In the advance program for the upcoming International Solid-State Circuits Conference to be held in San Francisco in late February 2022, there was this enigmatic presentation in the processors section.
Little beyond this was disclosed, but Ian Cutress of AnandTech has been digging around and has published what he has found in “Intel Has Two Generations of Bitcoin ASIC: BZM1 is Built on 7nm, 137 GigaHash/sec at 2.5 W”. “BZM” appears to stand for “Bonanza Mine”, and Intel appears to be developing two generations: BZM1 and BZM2. These are both application-specific integrated circuits (ASICs)—custom silicon designed to execute the SHA2-256 hashing algorithm which is the “inner loop” of Bitcoin mining as quickly and energy efficiently as possible. Cutress writes on BZM1:
Intel has two generations of SHA-256 ASIC. The first one, BZM1, is the topic of the talk at ISSCC. Intel is building the chip on a 7nm process. Exactly which isn’t stated – the documents we have state ‘7nm’, but the same document also refers to Intel 4 as ‘4nm’. In all likelihood, this means that BZM1 is being built at Intel, and this could be one of the first IDM 2.0 customers for Intel utilizing Intel’s in-house custom design team – the SEC filing is co-signed by Intel’s GM of Custom Accelerators, for context.
The chip is 14.16 mm² (so a maximum of 4000 chips per wafer), operates at 1.6 GHz, and generates 137 gigahash (137GH) per second at 2.5 W. 25 of these chips are used in a deep board configuration, voltage stacked at 335 mV per chip, totaling 8.875V main supply.
It’s worth noting that 335 mV per chip as a voltage minimum is insanely low. Intel says this is the most technically advanced Bitcoin ASIC to date, using an ultra-low voltage design, specialized clocking strategies, and other circuit and microarchitectural optimizations – more detail in the actual ISSCC talk in February.
A second generation BZM2 chip was disclosed in a SEC filing by Intel.
Intel’s second generation chip is listed in an SEC filing. According to the filing, it’s called BZM2, and there is already a financial agreement with a customer. The filing is a four-year supply agreement between Intel and Griid Infrastructure, starting on September 8th, 2021, and the BZM2 chip is designed specifically for SHA-256 cryptographic hash functions. While exact purchase agreement numbers are redacted, Griid is to supply an 18-month rolling forecast of requested supply that Intel will work towards, with a specific reservation quantity, and a minimum deposit at the start of the agreement. These chips will be delivered up to May 2023, although the contract can be extended. Intel provides no warranty on the chips except for DOA, and also provides 3-month support after each batch of chips are delivered.
There are two versions of BZM2, likely differing in power and performance, although the exact numbers are redacted. We have a single source that states BZM2 is being built on TSMC N5, offering 35 J/TH, which by the same metric would be a 37% power saving over the first generation. This information may not be correct however; we are looking to second source it.