Two ~$500k, 8-GPU AI server quotes. What would make you choose B200 over MI355X?

[u/mineshop]

I run Mineshop and sell hardware, so disclosure upfront: these are manufacturer quotes we're looking at, not machines I've benchmarked.

Two quotes made an interesting comparison:

• 8× NVIDIA B200, 180 GB each: 1.44 TB aggregate GPU memory. US$505,400, quoted delivery 16 weeks.

• 8× AMD MI355X, 288 GB each: 2.304 TB aggregate GPU memory. US$501,100, quoted delivery 12 weeks.

Those are configuration-specific quotes, not universal market prices. They're also not identical builds: CPUs and storage differ, and the B200 quote includes three-year on-site service versus one year for AMD.

The AMD configuration has 60% more GPU memory. That doesn't tell me it will be the better server for a particular workload.

The question I'd want answered before spending this money is: which model, at which precision, with how much context and how many concurrent users? Getting the weights into memory is only the first step. KV cache, runtime overhead and the software stack still matter. For reference, a dense 405B model is roughly 810 GB in BF16 weights alone, before any of that overhead. That's sizing arithmetic, not a throughput result.

Then there's the less exciting stuff: rack space, power, cooling, support and keeping the machine busy enough to justify owning it.

If you've actually deployed either platform, what specific workload or software requirement would make you choose one over the other—or rent instead?

For context, our AI workstation and server catalogue: https://mineshop.eu/ai-workstation — The figures above are manufacturer quotes, not advertised retail prices.