Initial tests for Kimi-K2.5 via KTransformers+SGLang, on a hybrid 4x RTX Pro 6000 Blackwell + 640GB/1.5TB CPU memory offload. Compute provided by Lium pods: - 19.97 output tok/s @ 10 concurrent requests - Mean TTFT: ~120s - Median TTFT: ~102s Need to play with the KT flags to further optimize this setup, which is heavily dependent on the overall system's CPU core count & available RAM. GPU <-> PCIe <-> RAM interconnectivity is the most obvious bottleneck Experts per MoE Layer on GPU: --kt-num-gpu-experts=128 CPU cores dedicated to MoE inference: --kt-cpuinfer=104 CPU experts work overlapping GPU work: --kt-max-deferred-experts-per-token=2 Max tokens per prefill chunk: --chunked-prefill-size=32658 CUDA graph capture disabled: --disable-cuda-graph
Yannick Nick
Yannick NickFeb 25, 2026
Running Kimi-K2.5 on 8x RTX Pro 6000 Blackwells, with plans to eventually test a CPU/GPU hybrid inference setup through KTransformers+SGLang on 4x of the same GPUs Very curious to gauge the overall performance with the hybrid setup compared to a quantized Kimi-K2.5 fit across the 4 GPUs. The hybrid setup will need close to 768GB of RAM To start here's a baseline across 8x GPUs using a synthetic coding agent style workload targeting 2k-45k input tokens, 80-3k max output tokens, and with up to 10 concurrent requests. SGLang's --mem-fraction-static flag is set to 0.90 Baseline avg throughput: ~74 output tokens/s @ 10 concurrent requests
KTransformers+SGLang flags to reproduce work: ========== export CUDA_VISIBLE_DEVICES=0,1,2,3 export OMP_NUM_THREADS=1 export MKL_NUM_THREADS=1 export OPENBLAS_NUM_THREADS=1 export NUMEXPR_NUM_THREADS=1 export VECLIB_MAXIMUM_THREADS=1 python -m sglang.launch_server \ --model-path <HF_PATH>/models--moonshotai--Kimi-K2.5/snapshots/3367c8d1c68584429fab7faf845a32d5195b6ac1 \ --kt-weight-path <HF_PATH>/models--moonshotai--Kimi-K2.5/snapshots/3367c8d1c68584429fab7faf845a32d5195b6ac1 \ --kt-cpuinfer 104 \ --kt-threadpool-count 2 \ --kt-num-gpu-experts 128 \ --kt-max-deferred-experts-per-token 2 \ --kt-method RAWINT4 \ --kt-gpu-prefill-token-threshold 400 \ --kt-expert-placement-strategy uniform \ --trust-remote-code \ --mem-fraction-static 0.90 \ --served-model-name kimi_k2 \ --tool-call-parser kimi_k2 \ --reasoning-parser kimi_k2 \ --disable-radix-cache \ --disable-chunked-prefix-cache \ --enable-mixed-chunk \ --tensor-parallel-size 4 \ --enable-p2p-check \ --disable-shared-experts-fusion \ --chunked-prefill-size 32658 \ --max-total-tokens 120000 \ --attention-backend flashinfer \ --disable-cuda-graph \ --host 0.0.0.0 \ --port 8000
141