49 KiB
DeepSeek-V4-Flash
1 Introduction
DeepSeek-V4 introduces several key upgrades over DeepSeek-V3:
- The Manifold-Constrained Hyper-Connections (mHC) to strengthen conventional residual connections.
- A hybrid attention architecture, which greatly improves long-context efficiency through Compress-4-Attention and Compress-128-Attention. For the Mixture-of-Experts (MoE) components, it still adopts the DeepSeekMoE architecture, with only minor adjustments.
DeepSeek-V4-Flash is the lightweight variant of the DeepSeek-V4 family, suitable for high-throughput and low-latency serving scenarios.
This document will show the main verification steps of the model, including supported features, feature configuration, environment preparation, single-node and multi-node deployment, accuracy and performance evaluation.
2 Supported Features
Refer to supported features to get the model's supported feature matrix.
Refer to feature guide to get the feature's configuration.
3 Prerequisites
3.1 Model Weight
DeepSeek-V4-Flash-w8a8-mtp(Quantized version): requires 1 Atlas 800 A3 (128GB × 8) node or 1 Atlas 800 A2 (64GB × 8) node. Download model weight- For Ascend 950DT servers, use the original
DeepSeek-V4-Flashweights released by DeepSeek on Hugging Face. The Attention weights use MXFP8, while the MoE weights use MXFP4 with 4-bit weights and 8-bit activation computation (W4A8). No Ascend-specific quantization or weight conversion is required. Both the mixed-deployment example in Section 5.1 and the intra-server 1P1D example in Section 5.2.3 use one Ascend 950DT server (96GB × 8). The mixed deployment uses four NPUs, while the 1P1D deployment assigns four NPUs to Prefill and four NPUs to Decode.
It is recommended to download the model weight to the shared directory of multiple nodes, such as /root/.cache/.
3.2 Verify Multi-node Communication (Optional)
If you want to deploy a multi-node environment, you need to verify multi-node communication according to verify multi-node communication environment.
4 Installation
4.1 Docker Image Installation
Select an image based on your machine type and start the docker image on your node, refer to using docker.
:::::{tab-set} :sync-group: install
::::{tab-item} Ascend 950DT series :sync: Ascend 950DT
Start the docker image on your each node.
:substitutions:
export IMAGE=quay.io/ascend/vllm-ascend:|vllm_ascend_version|-a5
export NAME=vllm-ascend
docker run --rm \
--name $NAME \
--net=host \
--shm-size=512g \
--device /dev/davinci0 \
--device /dev/davinci1 \
--device /dev/davinci2 \
--device /dev/davinci3 \
--device /dev/davinci4 \
--device /dev/davinci5 \
--device /dev/davinci6 \
--device /dev/davinci7 \
--device /dev/davinci_manager \
--device /dev/hisi_hdc \
--device /dev/ummu \
--device /dev/uburma \
-v /usr/local/Ascend/driver:/usr/local/Ascend/driver \
-v /etc/ascend_install.info:/etc/ascend_install.info \
-v /etc/hccl_rootinfo.json:/etc/hccl_rootinfo.json \
-v /etc/hixlep/:/etc/hixlep/ \
-v /root/.cache:/root/.cache \
-v /usr/local/sbin:/usr/local/sbin \
-v /usr/local/dcmi:/usr/local/dcmi \
-v /usr/local/bin/npu-smi:/usr/local/bin/npu-smi \
-v /usr/local/sbin/npu-smi:/usr/local/sbin/npu-smi \
-itd $IMAGE bash
:::: ::::{tab-item} A3 series :sync: A3
Start the docker image on each node.
:substitutions:
export IMAGE=quay.io/ascend/vllm-ascend:|vllm_ascend_version|-a3
docker run --rm \
--name vllm-ascend \
--shm-size=512g \
--net=host \
--device /dev/davinci0 \
--device /dev/davinci1 \
--device /dev/davinci2 \
--device /dev/davinci3 \
--device /dev/davinci4 \
--device /dev/davinci5 \
--device /dev/davinci6 \
--device /dev/davinci7 \
--device /dev/davinci8 \
--device /dev/davinci9 \
--device /dev/davinci10 \
--device /dev/davinci11 \
--device /dev/davinci12 \
--device /dev/davinci13 \
--device /dev/davinci14 \
--device /dev/davinci15 \
--device /dev/davinci_manager \
--device /dev/devmm_svm \
--device /dev/hisi_hdc \
-v /usr/local/dcmi:/usr/local/dcmi \
-v /usr/local/Ascend/driver/tools/hccn_tool:/usr/local/Ascend/driver/tools/hccn_tool \
-v /usr/local/bin/npu-smi:/usr/local/bin/npu-smi \
-v /usr/local/Ascend/driver/lib64/:/usr/local/Ascend/driver/lib64/ \
-v /usr/local/Ascend/driver/version.info:/usr/local/Ascend/driver/version.info \
-v /etc/ascend_install.info:/etc/ascend_install.info \
-v /etc/hccn.conf:/etc/hccn.conf \
-it $IMAGE bash
:::: ::::{tab-item} A2 series :sync: A2
Start the docker image on each node.
:substitutions:
export IMAGE=quay.io/ascend/vllm-ascend:|vllm_ascend_version|
docker run --rm \
--name vllm-ascend \
--shm-size=512g \
--net=host \
--device /dev/davinci0 \
--device /dev/davinci1 \
--device /dev/davinci2 \
--device /dev/davinci3 \
--device /dev/davinci4 \
--device /dev/davinci5 \
--device /dev/davinci6 \
--device /dev/davinci7 \
--device /dev/davinci_manager \
--device /dev/devmm_svm \
--device /dev/hisi_hdc \
-v /usr/local/dcmi:/usr/local/dcmi \
-v /usr/local/Ascend/driver/tools/hccn_tool:/usr/local/Ascend/driver/tools/hccn_tool \
-v /usr/local/bin/npu-smi:/usr/local/bin/npu-smi \
-v /usr/local/Ascend/driver/lib64/:/usr/local/Ascend/driver/lib64/ \
-v /usr/local/Ascend/driver/version.info:/usr/local/Ascend/driver/version.info \
-v /etc/ascend_install.info:/etc/ascend_install.info \
-v /etc/hccn.conf:/etc/hccn.conf \
-it $IMAGE bash
:::: :::::
After a successful docker run, you can verify the running container service by executing the docker ps command.
4.2 Source Code Installation
If you don't want to use the docker image as above, you can also build all from source:
- Install
vllm-ascendfrom source, refer to installation.
If you want to deploy a multi-node environment, you need to set up the environment on each node.
5 Online Service Deployment
:::{note}
In this tutorial, we suppose you downloaded the model weight to /root/.cache/. Feel free to change it to your own path.
:::
5.1 Single-Node Online Deployment
Single-node deployment completes both Prefill and Decode within the same node. The quantized model DeepSeek-V4-Flash-w8a8-mtp can be deployed on 1 Atlas 800 A3 (128GB × 8) or 1 Atlas 800 A2 (64GB × 8). The original DeepSeek-V4-Flash weights can be deployed on 1 Ascend 950DT server (96GB × 8).
:::::{tab-set} :sync-group: install
::::{tab-item} A2 series :sync: A2
Run the following script to execute online inference.
export OMP_PROC_BIND=false
export OMP_NUM_THREADS=10
export PYTORCH_NPU_ALLOC_CONF=expandable_segments:True
export LD_PRELOAD=/usr/lib/aarch64-linux-gnu/libjemalloc.so.2:$LD_PRELOAD
export HCCL_BUFFSIZE=1024
export VLLM_ASCEND_ENABLE_FLASHCOMM1=1
export TASK_QUEUE_ENABLE=1
export HCCL_OP_EXPANSION_MODE="AIV"
vllm serve /root/.cache/modelscope/hub/models/vllm-ascend/DeepSeek-V4-Flash-w8a8-mtp \
--max-model-len 133120 \
--max-num-batched-tokens 8192 \
--served-model-name dsv4 \
--gpu-memory-utilization 0.9 \
--max-num-seqs 32 \
--data-parallel-size 1 \
--tensor-parallel-size 8 \
--enable-expert-parallel \
--tokenizer-mode deepseek_v4 \
--tool-call-parser deepseek_v4 \
--enable-auto-tool-choice \
--reasoning-parser deepseek_v4 \
--safetensors-load-strategy 'prefetch' \
--no-enable-prefix-caching \
--model-loader-extra-config='{"enable_multithread_load": "true", "num_threads": 128}' \
--quantization ascend \
--port 8900 \
--block-size 128 \
--speculative-config '{"num_speculative_tokens": 1,"method": "mtp","enforce_eager": true}' \
--compilation-config '{"cudagraph_mode": "FULL_DECODE_ONLY"}' \
--async-scheduling \
--additional-config '
{"ascend_compilation_config":{
"enable_npugraph_ex":true,
"enable_static_kernel":false
},
"enable_cpu_binding": true,
"enable_dsa_cp": true,
"multistream_overlap_shared_expert":true}'
:::: ::::{tab-item} A3 series :sync: A3
Run the following script to execute online inference.
export OMP_PROC_BIND=false
export OMP_NUM_THREADS=10
export PYTORCH_NPU_ALLOC_CONF=expandable_segments:True
export LD_PRELOAD=/usr/lib/aarch64-linux-gnu/libjemalloc.so.2:$LD_PRELOAD
export HCCL_BUFFSIZE=1024
export VLLM_ASCEND_ENABLE_FLASHCOMM1=1
export TASK_QUEUE_ENABLE=1
export HCCL_OP_EXPANSION_MODE="AIV"
vllm serve /root/.cache/modelscope/hub/models/vllm-ascend/DeepSeek-V4-Flash-w8a8-mtp \
--max-model-len 1048576 \
--max-num-batched-tokens 10240 \
--served-model-name dsv4 \
--gpu-memory-utilization 0.9 \
--api-server-count 1 \
--max-num-seqs 64 \
--data-parallel-size 4 \
--tensor-parallel-size 4 \
--enable-expert-parallel \
--tokenizer-mode deepseek_v4 \
--tool-call-parser deepseek_v4 \
--enable-auto-tool-choice \
--reasoning-parser deepseek_v4 \
--safetensors-load-strategy 'prefetch' \
--model-loader-extra-config='{"enable_multithread_load": "true", "num_threads": 128}' \
--quantization ascend \
--port 8900 \
--block-size 128 \
--speculative-config '{"num_speculative_tokens": 1,"method": "mtp","enforce_eager": true}' \
--compilation-config '{"cudagraph_mode": "FULL_DECODE_ONLY"}' \
--async-scheduling \
--additional-config '
{"ascend_compilation_config":{
"enable_npugraph_ex":true,
"enable_static_kernel":false
},
"enable_cpu_binding": true,
"multistream_overlap_shared_expert":true}'
:::: ::::{tab-item} Ascend 950DT series :sync: Ascend 950DT
Run the following script to execute mixed online inference on one Ascend 950DT server.
export OMP_PROC_BIND=false
export OMP_NUM_THREADS=10
export PYTORCH_NPU_ALLOC_CONF=expandable_segments:True
export HCCL_BUFFSIZE=1024
export ASCEND_RT_VISIBLE_DEVICES=0,1,2,3
vllm serve /root/.cache/DeepSeek-V4-Flash \
--max-model-len 1048576 \
--safetensors-load-strategy prefetch \
--max-num-batched-tokens 4096 \
--served-model-name dsv4 \
--gpu-memory-utilization 0.9 \
--enable-expert-parallel \
--async-scheduling \
--max-num-seqs 64 \
--port 8900 \
--block-size 32 \
--tokenizer-mode deepseek_v4 \
--tool-call-parser deepseek_v4 \
--enable-auto-tool-choice \
--reasoning-parser deepseek_v4 \
--data-parallel-size 4 \
--api-server-count 1 \
--compilation-config '{"cudagraph_mode": "FULL_DECODE_ONLY"}' \
--speculative-config '{"num_speculative_tokens": 1, "method": "deepseek_mtp"}' \
--additional-config '{"enable_cpu_binding": true, "multistream_overlap_shared_expert": true, "enable_shared_expert_dp": true}'
:::: :::::
Key Parameter Descriptions:
--max-model-lenspecifies the maximum context length - that is, the sum of input and output tokens for a single request. Adjust it according to your actual scenario.--max-num-seqsindicates the maximum number of requests that each DP group is allowed to process. If the number of requests sent to the service exceeds this limit, the excess requests will remain in a waiting state and will not be scheduled. Note that the time spent in the waiting state is also counted in metrics such as TTFT and TPOT. Therefore, when testing performance, it is generally recommended that--max-num-seqs*--data-parallel-size>= the actual total concurrency.--max-num-batched-tokensis the maximum number of tokens processed in one scheduler step. A larger value can improve prefill efficiency but consumes more activation memory.--data-parallel-sizesets the global number of data parallel ranks, while--tensor-parallel-sizesets the tensor parallel size within each DP rank. Configure them together according to the deployment topology and available NPUs.- On Ascend 950DT, DeepSeek-V4 does not currently support standalone tensor parallelism (TP-only). TP partitions only the
wq_b,wo_a, andwo_blinear layers, so data parallelism is recommended. When TP is required, use it together with DSA-CP and enable FlashComm (enable_flashcomm1) and DSA-CP (enable_dsa_cp), as in the two-server DeepSeek-V4-Pro mixed deployment. --enable-expert-parallelenables expert parallelism for MoE layers. Do not mix MoE tensor parallelism and expert parallelism in the same MoE layer.--no-enable-prefix-cachingindicates that prefix caching is disabled. To enable it, remove this option.--block-sizesets the KV cache block size. To enable the experimental 4K prefix cache hit support, change it from128to32.--quantization ascendenables Ascend quantization for the W8A8 model used in the A2 and A3 configurations. The original DeepSeek-V4-Flash weights used on Ascend 950DT do not require this option.--speculative-configconfigures the MTP (Multi-Token Prediction) speculative decoding to accelerate inference.--compilation-config '{"cudagraph_mode":"FULL_DECODE_ONLY"}'enables full ACL graph execution in the decode phase to reduce scheduling latency.--async-schedulingenables asynchronous scheduling to overlap CPU scheduling with NPU computation.--additional-configenables Ascend-specific optimizations.enable_npugraph_exenables enhanced ACL graph execution,enable_static_kernel: falsekeeps static-kernel compilation disabled,enable_cpu_bindingenables Ascend-native CPU binding,enable_dsa_cpenables DSA context parallelism,enable_shared_expert_dpenables data parallelism for shared experts, andmultistream_overlap_shared_expertoverlaps shared expert computation for better MoE throughput. DSA-CP depends on FlashComm1, and both options must be enabled explicitly.VLLM_ASCEND_ENABLE_FLASHCOMM1=1enables the FlashComm communication optimization.
Common Issues Tip: If you encounter issues, please refer to the Public FAQ for troubleshooting.
Service Verification:
curl http://<node0_ip>:8900/v1/chat/completions \
-H "Content-Type: application/json" \
-d '{
"model": "dsv4",
"messages": [
{
"role": "user",
"content": "Who are you?"
}
],
"max_tokens": 256,
"temperature": 0
}'
Expected Result:
The service returns HTTP 200 OK with a JSON response containing the choices field.
5.2 Multi-Node PD Separation Deployment
We recommend using Mooncake for deployment: Mooncake.
In the standard single-node deployment mode, Prefill (prompt processing) and Decode (token generation) tasks run on the same set of NPUs. This can lead to two issues:
- Prefill preemption interrupts Decode: Prefill is a compute-intensive task that processes the entire input context at once, while Decode generates tokens one by one. When a new user request arrives, its Prefill phase can preempt and interrupt ongoing Decode tasks, causing jitter and higher time-per-output-token (TPOT) latency.
- Inflexible resource allocation: Prefill and Decode have fundamentally different computational characteristics — Prefill is compute-bound and memory-bandwidth-intensive, while Decode is memory-bandwidth-bound. Running them on the same hardware forces a compromise that satisfies neither optimally.
PD (Prefill-Decode) separation addresses these issues by running Prefill and Decode on dedicated node groups, each configured independently. This architecture is recommended for production deployments with concurrent multi-user workloads, where stable latency and high throughput are both required.
The following sections describe PD separation deployment on Atlas 800 A3 nodes (128GB × 8), Atlas 800 A2 nodes (64GB × 8), and Ascend 950DT servers (96GB × 8).
5.2.1 A3 Series PD Separation Deployment
This section shows the deployment guide of DeepSeek-V4-Flash on Atlas 800 A3 (128GB × 8) multi-node environment with 1P1D for better performance.
Before you start, please:
-
Prepare the script
launch_online_dp.pyon each node.import argparse import multiprocessing import os import subprocess import sys def parse_args(): parser = argparse.ArgumentParser() parser.add_argument( "--dp-size", type=int, required=True, help="Data parallel size." ) parser.add_argument( "--tp-size", type=int, default=1, help="Tensor parallel size." ) parser.add_argument( "--dp-size-local", type=int, default=-1, help="Local data parallel size." ) parser.add_argument( "--dp-rank-start", type=int, default=0, help="Starting rank for data parallel." ) parser.add_argument( "--dp-address", type=str, required=True, help="IP address for data parallel master node." ) parser.add_argument( "--dp-rpc-port", type=str, default=12345, help="Port for data parallel master node." ) parser.add_argument( "--vllm-start-port", type=int, default=9000, help="Starting port for the engine." ) return parser.parse_args() args = parse_args() dp_size = args.dp_size tp_size = args.tp_size dp_size_local = args.dp_size_local if dp_size_local == -1: dp_size_local = dp_size dp_rank_start = args.dp_rank_start dp_address = args.dp_address dp_rpc_port = args.dp_rpc_port vllm_start_port = args.vllm_start_port def run_command(visible_devices, dp_rank, vllm_engine_port): command = [ "bash", "./run_dp_template.sh", visible_devices, str(vllm_engine_port), str(dp_size), str(dp_rank), dp_address, dp_rpc_port, str(tp_size), ] subprocess.run(command, check=True) if __name__ == "__main__": template_path = "./run_dp_template.sh" if not os.path.exists(template_path): print(f"Template file {template_path} does not exist.") sys.exit(1) processes = [] num_cards = dp_size_local * tp_size for i in range(dp_size_local): dp_rank = dp_rank_start + i vllm_engine_port = vllm_start_port + i visible_devices = ",".join(str(x) for x in range(i * tp_size, (i + 1) * tp_size)) process = multiprocessing.Process(target=run_command, args=(visible_devices, dp_rank, vllm_engine_port)) processes.append(process) process.start() for process in processes: process.join()Parameter descriptions:
Parameter Type Required Default Description --dp-sizeint Yes - Data parallel size (total number of DP ranks across all nodes). --tp-sizeint No 1 Tensor parallel size within each DP rank. --dp-size-localint No (same as --dp-size)Number of DP ranks on the current node. If not set, defaults to --dp-size.--dp-rank-startint No 0 Starting rank offset for data parallel ranks on this node. --dp-addressstr Yes - IP address of the data parallel master node. --dp-rpc-portstr No 12345 RPC port for data parallel master communication. --vllm-start-portint No 9000 Starting port for each vLLM engine instance on this node. -
Prepare the script
run_dp_template.shon each node.-
Prefill node
nic_name="xxxx" # change to your own nic name local_ip=xx.xx.xx.1 # change to your own ip export HCCL_IF_IP=$local_ip export GLOO_SOCKET_IFNAME=$nic_name export TP_SOCKET_IFNAME=$nic_name export HCCL_SOCKET_IFNAME=$nic_name export VLLM_RPC_TIMEOUT=3600000 export VLLM_EXECUTE_MODEL_TIMEOUT_SECONDS=30000 export HCCL_EXEC_TIMEOUT=204 export HCCL_CONNECT_TIMEOUT=120 export OMP_PROC_BIND=false export OMP_NUM_THREADS=10 export PYTORCH_NPU_ALLOC_CONF=expandable_segments:True export HCCL_BUFFSIZE=2560 export TASK_QUEUE_ENABLE=1 export VLLM_ASCEND_ENABLE_FLASHCOMM1=1 export HCCL_OP_EXPANSION_MODE="AIV" export LD_PRELOAD=/usr/lib/aarch64-linux-gnu/libjemalloc.so.2:$LD_PRELOAD export ASCEND_RT_VISIBLE_DEVICES=$1 vllm serve /root/.cache/modelscope/hub/models/vllm-ascend/DeepSeek-V4-Flash-w8a8-mtp \ --host 0.0.0.0 \ --port $2 \ --data-parallel-size $3 \ --data-parallel-rank $4 \ --data-parallel-address $5 \ --data-parallel-rpc-port $6 \ --tensor-parallel-size $7 \ --enable-expert-parallel \ --seed 1024 \ --served-model-name dsv4 \ --max-model-len 1048576 \ --max-num-batched-tokens 8192 \ --max-num-seqs 16 \ --no-disable-hybrid-kv-cache-manager \ --model-loader-extra-config='{"enable_multithread_load": "true", "num_threads": 128}' \ --no-enable-prefix-caching \ --safetensors-load-strategy 'prefetch' \ --speculative-config '{"num_speculative_tokens": 1,"method": "mtp","enforce_eager": true}' \ --trust-remote-code \ --block-size 128 \ --tokenizer-mode deepseek_v4 \ --tool-call-parser deepseek_v4 \ --enable-auto-tool-choice \ --reasoning-parser deepseek_v4 \ --gpu-memory-utilization 0.9 \ --quantization ascend \ --enforce-eager \ --additional-config '{"enable_cpu_binding": true, "enable_shared_expert_dp": true, "enable_dsa_cp": true}' \ --kv-transfer-config \ '{"kv_connector": "MooncakeHybridConnector", "kv_role": "kv_producer", "kv_port": "30000", "engine_id": "0", "kv_connector_extra_config": { "prefill": { "dp_size": 4, "tp_size": 4 }, "decode": { "dp_size": 16, "tp_size": 1 } } }' -
Decode node
nic_name="xxxx" # change to your own nic name local_ip=xx.xx.xx.2 # change to your own ip export LD_PRELOAD=/usr/lib/aarch64-linux-gnu/libjemalloc.so.2:$LD_PRELOAD export HCCL_OP_EXPANSION_MODE="AIV" export TASK_QUEUE_ENABLE=1 export VLLM_RPC_TIMEOUT=3600000 export VLLM_EXECUTE_MODEL_TIMEOUT_SECONDS=30000 export HCCL_EXEC_TIMEOUT=204 export HCCL_CONNECT_TIMEOUT=1200 export HCCL_IF_IP=$local_ip export GLOO_SOCKET_IFNAME=$nic_name export TP_SOCKET_IFNAME=$nic_name export HCCL_SOCKET_IFNAME=$nic_name export OMP_PROC_BIND=false export OMP_NUM_THREADS=10 export PYTORCH_NPU_ALLOC_CONF=expandable_segments:True export HCCL_BUFFSIZE=1024 export ASCEND_RT_VISIBLE_DEVICES=$1 vllm serve /root/.cache/modelscope/hub/models/vllm-ascend/DeepSeek-V4-Flash-w8a8-mtp \ --host 0.0.0.0 \ --port $2 \ --data-parallel-size $3 \ --data-parallel-rank $4 \ --data-parallel-address $5 \ --data-parallel-rpc-port $6 \ --tensor-parallel-size $7 \ --enable-expert-parallel \ --seed 1024 \ --served-model-name dsv4 \ --max-model-len 1048576 \ --max-num-batched-tokens 120 \ --max-num-seqs 60 \ --async-scheduling \ --block-size 128 \ --no-disable-hybrid-kv-cache-manager \ --no-enable-prefix-caching \ --safetensors-load-strategy 'prefetch' \ --trust-remote-code \ --tokenizer-mode deepseek_v4 \ --model-loader-extra-config='{"enable_multithread_load": "true", "num_threads": 128}' \ --tool-call-parser deepseek_v4 \ --enable-auto-tool-choice \ --reasoning-parser deepseek_v4 \ --gpu-memory-utilization 0.9 \ --quantization ascend \ --speculative-config '{"num_speculative_tokens": 1,"method": "mtp","enforce_eager": true}' \ --compilation-config '{"cudagraph_mode": "FULL_DECODE_ONLY"}' \ --kv-transfer-config \ '{"kv_connector": "MooncakeHybridConnector", "kv_role": "kv_consumer", "kv_port": "30100", "engine_id": "1", "kv_connector_extra_config": { "prefill": { "dp_size": 4, "tp_size": 4 }, "decode": { "dp_size": 16, "tp_size": 1 } } }' \ --additional-config '{ "ascend_compilation_config":{ "enable_npugraph_ex":true, "enable_static_kernel":false }, "enable_cpu_binding":true, "multistream_overlap_shared_expert":true, "recompute_scheduler_enable":true }'
-
-
Start the server with the following command on each node.
-
Prefill node
# change ip to your own python launch_online_dp.py --dp-size 4 --tp-size 4 --dp-size-local 4 --dp-rank-start 0 --dp-address xx.xx.xx.1 --dp-rpc-port 12321 --vllm-start-port 7100 -
Decode node
# change ip to your own python launch_online_dp.py --dp-size 16 --tp-size 1 --dp-size-local 16 --dp-rank-start 0 --dp-address xx.xx.xx.2 --dp-rpc-port 12321 --vllm-start-port 7100
-
-
Deploy the P-D disaggregation proxy.
Refer to Prefill-Decode Disaggregation (Deepseek) to deploy the P-D disaggregation proxy.
5.2.2 A2 Series PD Separation Deployment
This section shows the deployment guide of DeepSeek-V4-Flash on Atlas 800 A2 (64GB × 8) multi-node environment with 4*1P 1*4D for better performance.
Before you start, please:
-
Prepare the script
launch_online_dp.pyon each node.import argparse import multiprocessing import os import subprocess import sys def parse_args(): parser = argparse.ArgumentParser() parser.add_argument("--dp-size", type=int, required=True, help="Data parallel size.") parser.add_argument("--tp-size", type=int, default=1, help="Tensor parallel size.") parser.add_argument("--dp-size-local", type=int, default=-1, help="Local data parallel size.") parser.add_argument("--dp-rank-start", type=int, default=0, help="Starting rank for data parallel.") parser.add_argument("--dp-address", type=str, required=True, help="IP address for data parallel master node.") parser.add_argument("--dp-rpc-port", type=str, default=12345, help="Port for data parallel master node.") parser.add_argument("--vllm-start-port", type=int, default=9000, help="Starting port for the engine.") return parser.parse_args() args = parse_args() dp_size = args.dp_size tp_size = args.tp_size dp_size_local = args.dp_size_local if dp_size_local == -1: dp_size_local = dp_size dp_rank_start = args.dp_rank_start dp_address = args.dp_address dp_rpc_port = args.dp_rpc_port vllm_start_port = args.vllm_start_port def run_command(visible_devices, dp_rank, vllm_engine_port): command = [ "bash", "./run_dp_template.sh", visible_devices, str(vllm_engine_port), str(dp_size), str(dp_rank), dp_address, dp_rpc_port, str(tp_size), ] subprocess.run(command, check=True) if __name__ == "__main__": template_path = "./run_dp_template.sh" if not os.path.exists(template_path): print(f"Template file {template_path} does not exist.") sys.exit(1) processes = [] num_cards = dp_size_local * tp_size for i in range(dp_size_local): dp_rank = dp_rank_start + i vllm_engine_port = vllm_start_port + i visible_devices = ",".join(str(x) for x in range(i * tp_size, (i + 1) * tp_size)) process = multiprocessing.Process(target=run_command, args=(visible_devices, dp_rank, vllm_engine_port)) processes.append(process) process.start() for process in processes: process.join() -
Prepare the script
run_dp_template.shon each node.-
Prefill node (4 P nodes share the same script)
For each P instance, only these two configuration values need to be modified:
kv_portandengine_id. Theengine_idshould start from 0 and increment sequentially, while thekv_port(e.g.,30100) must be unique for each P instance, such as 30000, 30100, etc.unset ftp_proxy unset https_proxy unset http_proxy rm -rf ~/ascend/log nic_name="xxxxxx" #eg."enp67s0f0np0" local_ip=`hostname -I|awk -F " " '{print$1}'` export LD_PRELOAD=/usr/lib/aarch64-linux-gnu/libjemalloc.so.2:$LD_PRELOAD export HCCL_OP_EXPANSION_MODE="AIV" export TASK_QUEUE_ENABLE=1 export VLLM_RPC_TIMEOUT=3600000 export VLLM_EXECUTE_MODEL_TIMEOUT_SECONDS=30000 export HCCL_EXEC_TIMEOUT=204 export HCCL_CONNECT_TIMEOUT=1200 export HCCL_IF_IP=$local_ip export GLOO_SOCKET_IFNAME=$nic_name export TP_SOCKET_IFNAME=$nic_name export HCCL_SOCKET_IFNAME=$nic_name export OMP_PROC_BIND=false export OMP_NUM_THREADS=10 export PYTORCH_NPU_ALLOC_CONF=expandable_segments:True export HCCL_BUFFSIZE=1024 export ASCEND_RT_VISIBLE_DEVICES=$1 export TASK_QUEUE_ENABLE=1 vllm serve /root/.cache/modelscope/hub/models/vllm-ascend/DeepSeek-V4-Flash-w8a8-mtp \ --host 0.0.0.0 \ --port $2 \ --data-parallel-size $3 \ --data-parallel-rank $4 \ --data-parallel-address $5 \ --data-parallel-rpc-port $6 \ --tensor-parallel-size $7 \ --enable-expert-parallel \ --seed 1024 \ --served-model-name dsv4 \ --max-model-len 135000 \ --max-num-batched-tokens 4096 \ --max-num-seqs 16 \ --block-size 128 \ --enforce-eager \ --async-scheduling \ --no-disable-hybrid-kv-cache-manager \ --enable-prefix-caching \ --trust-remote-code \ --gpu-memory-utilization 0.9 \ --quantization ascend \ --safetensors-load-strategy 'prefetch' \ --model-loader-extra-config='{"enable_multithread_load": "true", "num_threads": 128}' \ --tokenizer-mode deepseek_v4 \ --tool-call-parser deepseek_v4 \ --enable-auto-tool-choice \ --reasoning-parser deepseek_v4 \ --additional-config '{"enable_cpu_binding": true, "enable_shared_expert_dp": true}' \ --speculative-config '{"num_speculative_tokens": 1, "method": "mtp","enforce_eager": true}' \ --kv-transfer-config \ '{"kv_connector": "MooncakeHybridConnector", "kv_role": "kv_producer", "kv_port": "30000", "engine_id": "0", "kv_connector_extra_config": { "prefill": { "dp_size": 8, "tp_size": 1 }, "decode": { "dp_size": 32, "tp_size": 1 } } }' -
Decode node (4 D nodes share the same script)
unset ftp_proxy unset https_proxy unset http_proxy rm -rf ~/ascend/log nic_name="xxxxxx" #eg."enp67s0f0np0" local_ip=`hostname -I|awk -F " " '{print$1}'` export LD_PRELOAD=/usr/lib/aarch64-linux-gnu/libjemalloc.so.2:$LD_PRELOAD export HCCL_OP_EXPANSION_MODE="AIV" export TASK_QUEUE_ENABLE=1 export VLLM_RPC_TIMEOUT=3600000 export VLLM_EXECUTE_MODEL_TIMEOUT_SECONDS=30000 export HCCL_EXEC_TIMEOUT=204 export HCCL_CONNECT_TIMEOUT=1200 export HCCL_IF_IP=$local_ip export GLOO_SOCKET_IFNAME=$nic_name export TP_SOCKET_IFNAME=$nic_name export HCCL_SOCKET_IFNAME=$nic_name export OMP_PROC_BIND=false export OMP_NUM_THREADS=10 export PYTORCH_NPU_ALLOC_CONF=expandable_segments:True export HCCL_BUFFSIZE=1024 export ASCEND_RT_VISIBLE_DEVICES=$1 vllm serve /root/.cache/modelscope/hub/models/vllm-ascend/DeepSeek-V4-Flash-w8a8-mtp \ --host 0.0.0.0 \ --port $2 \ --data-parallel-size $3 \ --data-parallel-rank $4 \ --data-parallel-address $5 \ --data-parallel-rpc-port $6 \ --tensor-parallel-size $7 \ --enable-expert-parallel \ --seed 1024 \ --served-model-name dsv4 \ --max-model-len 135000 \ --max-num-batched-tokens 60 \ --max-num-seqs 30 \ --async-scheduling \ --block-size 128 \ --no-disable-hybrid-kv-cache-manager \ --no-enable-prefix-caching \ --trust-remote-code \ --gpu-memory-utilization 0.9 \ --quantization ascend \ --safetensors-load-strategy 'prefetch' \ --model-loader-extra-config='{"enable_multithread_load": "true", "num_threads": 128}' \ --tokenizer-mode deepseek_v4 \ --tool-call-parser deepseek_v4 \ --enable-auto-tool-choice \ --reasoning-parser deepseek_v4 \ --speculative-config '{"num_speculative_tokens": 1, "method": "mtp","enforce_eager": true}' \ --compilation-config '{"cudagraph_mode": "FULL_DECODE_ONLY"}' \ --kv-transfer-config \ '{"kv_connector": "MooncakeHybridConnector", "kv_role": "kv_consumer", "kv_port": "30400", "engine_id": "4", "kv_connector_extra_config": { "prefill": { "dp_size": 8, "tp_size": 1 }, "decode": { "dp_size": 32, "tp_size": 1 } } }' \ --additional-config '{ "ascend_compilation_config":{ "enable_npugraph_ex":true, "enable_static_kernel":false }, "enable_cpu_binding":true, "multistream_overlap_shared_expert":true, "recompute_scheduler_enable":true }'
-
-
Start the server with the following command on each node.
-
Prefill node
# change ip to your own python launch_online_dp.py --dp-size 8 --tp-size 1 --dp-size-local 8 --dp-rank-start 0 --dp-address x.x.x.x --dp-rpc-port 12321 --vllm-start-port 7100For each P instance, only the
--dp-addressparameter differs and must be configured as the IP address of the service within the same subnet as the other instances. -
Decode node
# change ip to your own python launch_online_dp.py --dp-size 32 --tp-size 1 --dp-size-local 8 --dp-rank-start x --dp-address x.x.x.x --dp-rpc-port 12321 --vllm-start-port 7100For each D instance, only the
--dp-rank-startparameter differs, which should be configured as 0, 8, 16, and 24 respectively. Each instance's--dp-addressmust be set to the IP address of the main D node, which is the IP of the Decode instance with--dp-rank-startset to 0.
-
-
Deploy the P-D disaggregation proxy.
The proxy is also implemented by referring to Prefill-Decode Disaggregation (Deepseek).
5.2.3 Ascend 950DT Series PD Separation Deployment
This section shows an intra-server 1P1D deployment on one Ascend 950DT server (96GB × 8). The Prefill instance uses NPUs 0-3 with DP4/TP1, and the Decode instance uses NPUs 4-7 with DP4/TP1. You can add Prefill or Decode instances as needed based on the workload's input/output characteristics and service requirements. An expert-parallel size (ep_size) of 4 is recommended for each instance. The prefill and decode parallel settings in --kv-transfer-config must match the actual engine settings after scaling.
Before starting the service, mount /etc/hixlep/ into the container and replace nic_name, local_ip, and the model path with values from your environment.
-
Prepare
run_prefill.sh.#!/usr/bin/env bash source /root/.bashrc nic_name="xxx" local_ip="xx.xx.xx.1" export HCCL_IF_IP=$local_ip export GLOO_SOCKET_IFNAME=$nic_name export TP_SOCKET_IFNAME=$nic_name export HCCL_SOCKET_IFNAME=$nic_name export HCCL_ALGO=level0:fullmesh export VLLM_RPC_TIMEOUT=3600000 export VLLM_EXECUTE_MODEL_TIMEOUT_SECONDS=30000 export HCCL_EXEC_TIMEOUT=204 export HCCL_CONNECT_TIMEOUT=120 export HCCL_BUFFSIZE=512 export LD_LIBRARY_PATH=/usr/local/lib:$LD_LIBRARY_PATH export ASCEND_LOCAL_COMM_RES_PATH=/etc/hixlep/ export OMP_PROC_BIND=false export OMP_NUM_THREADS=10 export PYTORCH_NPU_ALLOC_CONF=expandable_segments:True export ASCEND_RT_VISIBLE_DEVICES=0,1,2,3 vllm serve /root/.cache/DeepSeek-V4-Flash \ --host $local_ip \ --port 8000 \ --data-parallel-size 4 \ --data-parallel-address $local_ip \ --data-parallel-rpc-port 12321 \ --tensor-parallel-size 1 \ --max-model-len 1048576 \ --max-num-batched-tokens 3072 \ --served-model-name dsv4 \ --gpu-memory-utilization 0.85 \ --enable-expert-parallel \ --async-scheduling \ --max-num-seqs 8 \ --block-size 32 \ --api-server-count 1 \ --tokenizer-mode deepseek_v4 \ --tool-call-parser deepseek_v4 \ --enable-auto-tool-choice \ --reasoning-parser deepseek_v4 \ --trust-remote-code \ --enforce-eager \ --no-disable-hybrid-kv-cache-manager \ --speculative-config '{"num_speculative_tokens": 1, "method": "mtp"}' \ --kv-transfer-config \ '{"kv_connector": "MooncakeHybridConnector", "kv_role": "kv_producer", "kv_port": "36010", "engine_id": "1", "kv_connector_extra_config": { "prefill": { "dp_size": 4, "tp_size": 1 }, "decode": { "dp_size": 4, "tp_size": 1 }, "ascend_local_comm_res_path": "/etc/hixlep" } }' \ --additional-config '{"enable_cpu_binding": true}' -
Prepare
run_decode.sh.#!/usr/bin/env bash source /root/.bashrc nic_name="xxx" local_ip="xx.xx.xx.1" export HCCL_IF_IP=$local_ip export GLOO_SOCKET_IFNAME=$nic_name export TP_SOCKET_IFNAME=$nic_name export HCCL_SOCKET_IFNAME=$nic_name export HCCL_ALGO=level0:fullmesh export VLLM_RPC_TIMEOUT=3600000 export VLLM_EXECUTE_MODEL_TIMEOUT_SECONDS=30000 export HCCL_EXEC_TIMEOUT=2040 export HCCL_CONNECT_TIMEOUT=1200 export HCCL_BUFFSIZE=1024 export LD_LIBRARY_PATH=/usr/local/lib:$LD_LIBRARY_PATH export ASCEND_LOCAL_COMM_RES_PATH=/etc/hixlep/ export OMP_PROC_BIND=false export OMP_NUM_THREADS=10 export PYTORCH_NPU_ALLOC_CONF=expandable_segments:True export ASCEND_RT_VISIBLE_DEVICES=4,5,6,7 vllm serve /root/.cache/DeepSeek-V4-Flash \ --host $local_ip \ --port 8001 \ --data-parallel-size 4 \ --data-parallel-address $local_ip \ --data-parallel-rpc-port 12325 \ --tensor-parallel-size 1 \ --max-model-len 1048576 \ --max-num-batched-tokens 256 \ --served-model-name dsv4 \ --gpu-memory-utilization 0.92 \ --enable-expert-parallel \ --async-scheduling \ --max-num-seqs 56 \ --block-size 32 \ --no-enable-prefix-caching \ --tokenizer-mode deepseek_v4 \ --tool-call-parser deepseek_v4 \ --enable-auto-tool-choice \ --reasoning-parser deepseek_v4 \ --trust-remote-code \ --no-disable-hybrid-kv-cache-manager \ --compilation-config '{"cudagraph_mode": "FULL_DECODE_ONLY"}' \ --speculative-config '{"num_speculative_tokens": 1, "method": "mtp", "enforce_eager": false}' \ --kv-transfer-config \ '{"kv_connector": "MooncakeHybridConnector", "kv_role": "kv_consumer", "kv_port": "36010", "engine_id": "1", "kv_connector_extra_config": { "prefill": { "dp_size": 4, "tp_size": 1 }, "decode": { "dp_size": 4, "tp_size": 1 }, "ascend_local_comm_res_path": "/etc/hixlep" } }' \ --additional-config '{"enable_cpu_binding": true, "recompute_scheduler_enable": true, "multistream_overlap_shared_expert": true}' -
Start the Prefill and Decode services in separate terminals.
# Prefill terminal bash run_prefill.sh # Decode terminal bash run_decode.sh -
Deploy the P-D disaggregation proxy.
Refer to Prefill-Decode Disaggregation (Deepseek) and configure the Prefill endpoint as
<local_ip>:8000and the Decode endpoint as<local_ip>:8001.
Key Parameter Descriptions:
--no-disable-hybrid-kv-cache-managerkeeps the hybrid KV cache manager enabled. DeepSeek-V4 KV Pool deployments require this flag; otherwise, the service may OOM during startup.--enforce-eagerforces eager execution on prefill nodes instead of graph compilation.kv_connector_extra_config.prefill.dp_size/tp_sizeanddecode.dp_size/tp_sizemust match the actual global DP and TP layout on the prefill and decode sides.VLLM_ASCEND_ENABLE_FLASHCOMM1=1: enables the communication optimization function on the prefill nodes.recompute_scheduler_enable: true: enables the recomputation scheduler. When the KV Cache of the decode node is insufficient, requests will be sent to the prefill node to recompute the KV Cache. In the PD separation scenario, enable this configuration only on decode nodes.MooncakeHybridConnector: the KV transfer connector used for PD separation, transferring KV Cache between prefill and decode nodes.enable_shared_expert_dp: true: enables data parallelism for shared experts, applicable to MoE models.- On Ascend 950DT,
ascend_local_comm_res_pathspecifies the local communication resource directory used by the KV connector. The directory must be available at the same path in the container.
Deployment Verification:
After the PD separation service is fully started, send a request through the proxy port on the prefill master node to verify that Prefill and Decode nodes are working correctly together. Refer to Prefill-Decode Disaggregation (Deepseek) for the proxy verification method.
Common Issues Tip: If you encounter issues with PD separation deployment, please refer to the Public FAQ for troubleshooting.
5.2.4 Ultra-Long Sequence Deployment
For ultra-long sequence scenarios, support can be achieved by adjusting the PD (Prefill/Decode) ratio and the model parallelism strategy. For example, in a 1M sequence scenario, a 1*4P-1*4D ratio can be used, with the model parallelism set to DP4TP8 mode.
6 Functional Verification
Once your server is started, you can query the model with input prompts:
In <node0_ip>:, use the IP address and port number of the primary node. If the primary and standby nodes are separated, use the IP address and port number of the proxy node.
curl http://<node0_ip>:<port>/v1/chat/completions \
-H "Content-Type: application/json" \
-d '{
"model": "dsv4",
"messages": [
{
"role": "user",
"content": "Who are you?"
}
],
"max_tokens": 256,
"temperature": 0
}'
Expected Result:
The service returns HTTP 200 OK with a JSON response containing the choices field.
7 Accuracy Evaluation
Here is the accuracy evaluation method using AISBench.
Using AISBench
-
Refer to Using AISBench for details.
-
After execution, you can get the result.
| dataset | version | metric | mode | vllm-api-general-chat | note |
|---|---|---|---|---|---|
| GPQA | - | accuracy | gen | 88.17 | 1 Atlas 800 A3 (128GB × 8) |
| GSM8K | - | accuracy | gen | 96.30 | 1 Atlas 800 A3 (128GB × 8) |
8 Performance Evaluation
Using AISBench
Refer to Using AISBench for performance evaluation for details.
Using vLLM Benchmark
Refer to vllm benchmark for more details.
9 Performance Tuning
9.1 Recommended Configurations
Note
: The following configurations are validated in specific test environments and are for reference only. The optimal configuration depends on factors such as maximum input/output length, prefix cache hit rate, precision requirements, and deployment machine ratios. It is recommended to refer to Section 9.2 for tuning based on actual conditions.
Table 1: Scenario Overview
*Total NPUsindicates the total number of NPUs used across all nodes.
| Scenario | Deployment Mode | *Total NPUs | Weight Version | Key Considerations |
|---|---|---|---|---|
| High Throughput | Single-Node Mixed | 16 (A3) | DeepSeek-V4-Flash-w8a8-mtp | Use dp4 tp4 to balance memory capacity and compute efficiency |
| High Throughput / Long Context (1M) | Single-Node Mixed | 4 (Ascend 950DT) | DeepSeek-V4-Flash | Use dp4 tp1 with expert parallelism |
| High Throughput | 1P1D deployment | 32 (A3) | DeepSeek-V4-Flash-w8a8-mtp | dp16 tp1 on both P and D nodes; balanced latency and throughput |
| Long Context (1M) | Single-Node (A3) | 8 (A3) | DeepSeek-V4-Flash-w8a8-mtp | Use dp4 tp4 to balance memory capacity and compute efficiency |
| Long Context (1M) | 1P1D deployment | 32 (A3) | DeepSeek-V4-Flash-w8a8-mtp | dp16 tp1 on both P and D nodes; balanced latency and throughput |
| Long Context (1M) | 1P1D deployment | 8 (Ascend 950DT) | DeepSeek-V4-Flash | Split one Ascend 950DT server into P and D groups; both groups use dp4 tp1 |
Table 2: Detailed Node Configuration
| Scenario | Configuration | NPUs | TP | DP | Max Num Seqs | Max Num Batched Tokens | Max Model Len | MTP Speculation Num |
|---|---|---|---|---|---|---|---|---|
| High Throughput (A3) | Server / Single Machine | 8 | 4 | 4 | 64 | 10240 | 1048576 | 1 |
| Single-Node Mixed (Ascend 950DT) | Server / Single Machine | 4 | 1 | 4 | 64 | 4096 | 1048576 | 1 |
| Long Context (1M, A3) | Server / Single Machine | 8 | 4 | 4 | 64 | 10240 | 1048576 | 1 |
| PD Separation (A3) | Server-P Node | 8 | 4 | 4 | 16 | 8192 | 1048576 | 1 |
| PD Separation (A3) | Server-D Node | 8 | 1 | 16 | 60 | 120 | 1048576 | 1 |
| PD Separation (Ascend 950DT) | Prefill Group | 4 | 1 | 4 | 8 | 3072 | 1048576 | 1 |
| PD Separation (Ascend 950DT) | Decode Group | 4 | 1 | 4 | 56 | 256 | 1048576 | 1 |
For complete startup commands and parameter descriptions, please refer to the deployment examples in Chapter 5.
9.2 Tuning Guidelines
9.2.1 General Tuning Reference
Please refer to the Public Performance Tuning Documentation for tuning methods.
Please refer to the Feature Guide for detailed feature descriptions.
10 FAQ
For common environment, installation, and general parameter issues, please refer to the Public FAQ; this chapter only covers model-specific issues.