dgx sparks and new models my tests and results

We have four Sparks, arranged as two ConnectX-7 pairs. Over the last week we tried DeepSeek V4 Flash, Qwen3.8 Flash Next, Qwen3.8-27B and Qwen3.6-35B-A3B. The following tables are our preserved local results—not estimates copied from model cards. Recipe and context summary Model / recipe Hardware Runtime / acceleration Served context Longest demonstrated prompt Active paths DeepSeek V4 Flash 0731 2x Spark, TP2 vLLM, NVFP4 MLA KV, DSpark MTP5 probabilistic 1,048,576 899,994 passed 6 Qwen3.8 Flash Next NVFP4 2x Spark, TP2 SGLang, QSA, NEXTN, FlashInfer GDN 262,144 250,000 passed on slower no-NEXTN recipe 6 Qwen3.8-27B NVFP4 1x or 2x Spark SGLang, DFlash2 K8, FP8 KV 262,144 benchmark prompts; near-limit soak pending 8 per replica / 12 effective TP2 Qwen3.6-35B-A3B NVFP4 1x Spark vLLM, Marlin MoE, DSpark K8, FP8 KV 262,144 workload prompts 16 This local pilot used 12 LCB_generation plus 12 coding_completion questions, four concurrent API requests, streaming, no tools and the same network-disabled execution grader. It is not an official LiveBench submission. Delivered tok/s is API-accounted output divided by whole-batch wall time, including prefill, scheduling, reasoning and tail failures—not decode-only speed. Model / thinking Score API success Wall Output tokens Delivered tok/s Median task Worst task Qwen3.8-27B TP2 — off 18/24 24/24 2:49 32,186 190.0 5.33s 140.01s Qwen3.8-27B TP2 — low 19/24 23/24 10:47 56,339 recorded; ~89K actual 87.0 recorded 26.63s 583.73s Qwen3.8 Flash Next — off 17/24 24/24 1:22 8,861 107.7 4.43s 40.29s Qwen3.8 Flash Next — low 21/24 24/24 8:32 43,528 85.0 28.95s 447.88s Qwen3.8 Flash Next — medium 22/24 24/24 11:07 51,931 77.9 35.31s 581.91s Qwen3.8 Flash Next — xhigh 19/24 22/24 46:46 171,111 61.0 191.43s 1,453.16s DeepSeek V4 Flash — low 20/24 24/24 25:09 149,236 98.9 146.25s 993.19s DeepSeek V4 Flash — high 16/24 20/24 1:05:15 at least 255,175 at least 65.2 556.85s 1,449.81s The operational lessons were clearer than the one-run score differences: Flash Next medium had the best observed score, 22/24. Low was the better everyday balance at 21/24. Flash Next off completed the whole batch fastest and was extremely concise. Qwen27 low bought one extra pass for 3.82x the wall time, and one response ran into its 32K ceiling. DeepSeek low generated 2.65x as many output tokens as Qwen27 low and took 25 minutes. Its reason to retain is the separately demonstrated ~900K prompt, not speed on this test. High/xhigh thinking was actively counterproductive here. Flash Next xhigh used over 3x the medium output tokens and scored worse; DeepSeek high was worse again. We also tested Qwen3.6-35B-A3B earlier on a separate RTX 4090 FP8 endpoint: it reached 118.12 tok/s c1 and 784.68 aggregate at c16, with only 32K served context. On a comparable 12-task complete-program subset it scored 11/12 thinking off; low thinking also scored 11/12 while using 7.84x as many tokens. That row is excluded from the 24-task table because both the task count and hardware differ. These are all measured results, but prompt shapes and output lengths differ between recipe-native tests. They are useful deployment operating points, not a single architecture-normalized leaderboard. Model / topology Single-stream result C4 aggregate C6/C8 aggregate Best useful saturation DeepSeek V4 Flash, 2x Spark TP2 79.4 tok/s forced predictable decode; 42.08 free-form 512 79.53 free-form 99.26 at c6; 89.81 at c8 with two queued c6, 99.26 tok/s Qwen3.8 Flash Next, 2x Spark TP2 51.06 fixed 512 96.32 fixed 512 184.03 at c6 fixed 512 c6, 184.03 tok/s Qwen3.8-27B, 1x Spark 65.51 code / 31.93 prose ndec; 27.02 fixed-256 harness — 140.76 at c8 fixed 256 c8, 140.76 tok/s Qwen3.8-27B, 2x Spark TP2 100.08 code / 47.06 prose ndec; 39.29 fixed-256 harness 124.58 fixed 256 175.34 at c8 c12, 199.98 tok/s Qwen3.8-27B, 2 independent replicas 65.51 code per Spark — 157.38 at c8 c16, 286.93 tok/s Qwen3.6-35B-A3B, 1x Spark 80.69 fixed 256 195.10 277.55 at c8 c16, 404.89 tok/s For Flash Next, disabling NEXTN gave 26.4 tok/s at c1 and 111.8 tok/s aggregate at c6. On the current fixed-512 workload, NEXTN raised single-stream speed by about 1.9x and c6 throughput by about 1.65x. DeepSeek's ~80 tok/s headline was reproducible, but only on predictable forced output where speculative acceptance is high. The same live recipe managed 42 tok/s on open-ended free-form output. Reporting only the 80 would have been technically true and operationally misleading. Qwen3.8-27B topology test All rows below generated 256 tokens with thinking off: Deployment Concurrency Aggregate tok/s Wall Observation One Spark / one replica 1 27.02 9.47s fixed-output harness One Spark / one replica 8 140.76 14.55s saturated Two independent replicas 8 157.38 12.79s no queue Two independent replicas 16 286.93 14.28s best shared-capacity point Two independent replicas 32 284.73 28.77s 16 queued Two Sparks / TP2 1 39.29 6.52s fastest topology in this harness Two Sparks / TP2 8 175.34 — no queue Two Sparks / TP2 12 199.98 15.36s useful saturation Two Sparks / TP2 16 184.57 22.19s four queued TP2 made one long coding stream 1.53x faster—65.51 to 100.08 tok/s in the ndec code probe—but two independent replicas delivered 43% more aggregate throughput at saturation and isolate failures. Qwen3.6-35B-A3B on one Spark This MoE is our non-thinking transcript/JSON worker. Fixed 256-token deterministic outputs: Concurrency Aggregate tok/s Mean stream tok/s Mean TTFT 1 80.69 80.72 0.118s 2 126.19 64.46 0.155s 4 195.10 50.53 0.189s 8 277.55 36.74 0.242s 16 404.89 26.81 0.348s 32 382.64 18.08 5.959s