Reddit user claims 768GB of VRAM from twelve unlocked mining cards, with no benchmark attached
A Reddit user says twelve unlocked CMP 170HX mining cards give him 768GB of VRAM for less than one RTX PRO 6000 — with no tokens/sec figure and no receipt.
Vlad Makarovreviewed and published
A Reddit user says he is running 768GB of VRAM on twelve firmware-unlocked NVIDIA CMP 170HX mining cards, for less than the price of one RTX PRO 6000. It went up on r/LocalLLaMA on September 18, drawing roughly 820 points and more than 330 comments. "Here's my latest build, 12x64gb cmp170hx," writes u/segmond. "For less than 1 RTX 6000 pro costs. I also have it connected with fiber to my other rig for RPC when I need more memory."
Twelve cards is not one GPU
"the 768gb is the headline, but the number i actually want to see is tok/s on a dense model," wrote Ianhsieh_1031, noting an NVLink domain "tops out well before 12," so tensor-parallel groups cross a slow interconnect, where "tp basically falls over." The 170HX has no NVLink, and the unlock runs over PCIe Gen 2 x4 unless the board is modded for x16. The fiber link is llama.cpp's RPC backend — memory pooling, not a fabric — and segmond's numbers are modest: "Running DeepSeekV4Flash-Q2 — gigabit ethernet — 124PP, 24TG, with RDMA 274PP, 32TG." Neither "Tokens/s?" nor "So whats the performance like?" drew a figure.
Unlocked mining silicon, no warranty
The CMP 170HX is a 2021 mining card: a cut-down A100 GA100 nominally shipping with 8GB or 10GB of HBM2e. CMPUnlocker, a community tool, exposes the memory the firmware fused off — 64GB on 8GB boards, 40GB on the 10GB ones — and restores full throughput. Per Wccftech's write-up: some stacks are defective dies NVIDIA disabled on purpose, 64GB stability is not guaranteed, bandwidth runs about 700-800 GB/s per board, and no FP8 or FP4. segmond knew the terms: "no warranty and exchange only on DOA, and no promise that it will unlock."
The arbitrage that made it cheap is closing
The card he is beating, the RTX PRO 6000 Blackwell Workstation Edition, carries 96GB of GDDR7 and lists at $16,000 on NVIDIA's marketplace, against an $8,565 launch MSRP. Twelve unlocked 170HXs at today's prices is not cheaper: a tested, x16-modded 64GB board lists on eBay at $2,706. "You cant get 12 CMP 170hx for less than a pro 6000," wrote Hannibalj2ca. Wccftech dates the move: cards sat near $100-$200 before the unlock, then passed $1,000 overnight. segmond says he bought earlier, and publishes no receipt or power draw.
A trend summary attached to the thread credits it with "NVIDIA M40 GPUs at <$15k total" and "40 tokens/sec on 400B-parameter models." None of it is in the post, which names CMP 170HX cards and states neither a dollar total nor a tokens/sec figure. What would settle it: tokens/sec at named context lengths and quantisations, wall power, and a bill of materials. Until then 768GB is a capacity claim, and capacity is the easy part — as our own budget-VRAM coverage found.
