Shopping for Unlocked Mining Silicon
The CMP 170HX is A100-class silicon that unlocks to 64 GB of HBM2e. Buying two meant mapping a market that is part bargain, part minefield.
The NVIDIA CMP 170HX is a cryptomining card built on the same GA100 die as the A100: passive slab, no display outputs, and 1.49 TB/s of HBM2e that shipped artificially limited. A community unlock — writing feature-override registers after opening the protection layer via a GSP Falcon exploit — restores it to 64 GB. That makes it, on paper, the cheapest high-bandwidth VRAM money can buy. I wanted two for a local inference box.
“On paper” was carrying a lot of weight, so I did the market survey properly: every live listing across Facebook Marketplace (six metro areas), eBay, Alibaba, and AliExpress, with seller-fraud research on each. Findings, in ascending order of surprise:
The card barely trades socially. Three live Facebook listings existed across all six markets combined. This is not a liquid asset.
AliExpress inventory was 100% one scam operation. Every listing traced to a single storefront lineage — a repurposed jewelry shop, renamed, zero percent positive feedback — plus roughly fifty letter-prefixed clones. My favorite bait: a C$2,150 card with C$5,199 shipping. If you’ve seen a too-good 170HX price there, you’ve seen this cluster.
Facebook beat eBay in every cross-listed case. Same sellers, same physical cards, consistently cheaper off-platform — spreads from a few hundred dollars to nearly half price. Marketplace fees are real and sellers price them in.
AI-generated product photos are not a scam tell. The best-vetted seller in the whole survey used obviously generated hero shots; a confirmed fraud used stolen photographs of real inventory (0% positive feedback — 67 ratings across 350 sales — reusing a legitimate listing’s exact title). The photo’s provenance told me nothing; the feedback ledger did.
The market prices variants irrationally. 8 GB and 10 GB stock versions sell for the same money despite different claimed unlock ceilings — nobody bidding on these cards seems to price the thing that actually matters.
Where it landed
Two cards, negotiated in person at C$3,000 each. Post-unlock that’s about C$47 per GB of driver-supported, >1 TB/s VRAM. The cheapest fully-supported alternative I could verify from real sold listings — an RTX A6000 — runs about C$117/GB. (How I verified those comparison prices is its own story about estimates, and I didn’t come out of it looking great.)
Background reading that earned its place: the VideoCardz spec sheet, and niconiconi’s teardown and watercooling notes — the single best independent documentation of this card. The register-override mechanism is documented for the sibling card in the cmp90hx-unlock repository and the surrounding NVIDIA-patcher discussion.
Update (Sep 8): both cards arrived, validated as genuine boards from the same production batch, matching power dongles included. The unlock, the external chassis, and what 1.49 TB/s actually does for MoE inference are future posts.