[Neywiny]

Yes. Let's do the math. The fastest sd cards can read at around 300 MB/s (https://havecamerawilltravel.com/fastest-sd-cards/). Modern GPUs use 16 lanes of PCIe gen 5, which is 16x32Gb/s = 512Gb/s = 64 GB/s. Meaning you'd need over 200 of the fastest SD cards. So what you're asking is: is there a reason GPUs don't use 200 SD cards? And I can't think of any way that would work

[hedgehog]

SD is obviously the wrong interface for this but "High Bandwidth Flash" (stacked flash akin to HBM) is in development for exactly this kind of problem. AMD actually made a GPU with onboard flash maybe a decade ago but I think it was a bit early. Today I would love to have a pool of 50GB/s storage attached to the GPU.

[jiggawatts]

First gen HBF is targeting something like 1.2 TB/s!

[Dylan16807]

One thing to note, those aren't the fastest SD cards, those are the fastest UHS-II SD cards. The future is SD Express and you can already get microSDs at 900 MB/s.

[Neywiny]

SD expires cards are still on my watch list after seeing this https://www.theverge.com/2021/9/9/22665216/sd-express-card-s.... But even then, that's only 3x faster, so you're still putting down 71 ish (I think my original number was 213.33) cards, which means 71 PCIe PHYs and NVMe stacks.

[magicalhippo]

Some years ago I realized that if I had oodles of money to spend I would totally get someone to make a PCIe card with like several hundreds microSD cards on it.

You can buy vertical microSD connectors, so you can stack quite a lot of them on a PCIe card. Then a beefy FPGA to present it as a NVMe device to the host.

Goal total capacity, as you can put 1TB cards in there. And for teh lulz of course.

[15155]

This isn't a very difficult thing to build, but I am curious - what's the point? Who is the market?