Ask HN: Use RAM sticks as SATA drives
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PCIE RAM that looks like a disk would be useful for running Llama and other but models, on systems that cap out at 128 GB max. Using FlexGen or other disk offloading… Interesting idea.
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Idea of using RAM as a block storage died when $/GB and $/IOPS dropped (with DDR3 and SSD). As you can see nobody bothered with them since 2010[0]
> Also, I presume that a SATA interface to store data in RAM might have better performance than the average SSD. That totally depends on the silicon capabilities and still would be limited by the SATA. Sure, you would have a very low latency on a random IO, but anything with serious throughput (especially if the block size is small) would quickly saturate the bus. You can see it comparing SATA and NVMe drives from the same vendor and model range. And a personal anecdote – couple of years ago I did played with a software RAM drive (guess I needed something with tons of IO on a moderate sized load?) and the performance was… not good. Sure, it was a software written by some enthusiast and probably wasn’t optimized, but still. Modern SSDs are around $100-150 per TB, so you would get a better size and performance just buying an NVMe drive, with something like M.2 to PCI-E adapter[1] if needed. PS of course you can just buy an old server mobo and fill it out with your RAM sticks, make a software RAM drive and expose it over Ethernet with iSCSI or FCoE… but again that wouldn’t be cheaper than $100-150 NVMe drive. [0] https://en.wikipedia.org/wiki/RAM_drive, beneath “Devoted {hardware} RAM drives” [1] https://www.amazon.com/s?k=m.2+PCIe+converter+card |
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I’m not sure if one exists, but I think running it over SATA would defeat the purpose of using a RAM disk in the first place. Can I ask why you wouldn’t use a SATA SSD instead?
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Transfer speed is not everything, latency for random access is one important factor and also performance with randomly accessing many small files… Something even nvme drives are not that fast with…
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