21–26 of 26 posts
With ddr5 entering mainstream we will soon have a lot of used ddr3 and ddr4 modules available for cheap.
Is this for real? The store, which looks pretty amateurish, has no products for sale ("out of stock") and the prices are vastly too good to be true. DDR3 memory for 40c per gigabyte? Cheapest I can see on Amazon is 5 times that. 256GB of memory (plus the board itself) for $280? Not possible. Sorry, I don't believe it.
"refan" I think they might be talking about factory reject recycled/repaired ram. Chuck Peddle (6502) had some patents for this and ran operations in Asia for a company doing this on a large scale "Memory module assembly using partially defective chips" https://patents.justia.com/patent/6119049 https://patents.justia.com/patent/RE39016
Oral History of Charles Ingerham “Chuck” Peddle https://archive.computerhistory.org/resources/access/text/20...
>Peddle: I had a patent on how to use partial DRAM. And we turned that patent into a very large business making DRAM in Sri Lanka, in India, using reject die from Micron.
>Peddle: We buy the good ones in the front, probably about half price because they sell them about half price. Although we buy them less than half price because a lot of them don't make the 50% numbers that other people are looking for. And then the ones in the back, we basically almost get free because we can use them up.
That business died when Micron stopped selling partials(reject dies) to anyone but their subsidiary SpecTech. "SpecTek began at Micron in 1988 as a component-recovery group. In the two decades since its inception, the company has grown from an internal group to a manufacturing division; that experience has produced a product portfolio and reputation that makes SpecTek a leader in application-specific memory solutions.". Every time you buy Crucial you might be buying inferior SpecTek factory remanufactured/patched from defects product.
> We lost 4,500 jobs in a weekend when they stop selling partials.
Nowadays a TON of Chinese brands are into partials. Cheap flash memory was first - why throw away 90% defective flash die when you can make small SD card/USB drive out of it. I have no doubt they moved to ram now.
For the rest, in current chip shortage $280 wouldnt even cover 4 FPGAs pictured on that website :)
Out of interest, would you get a similar bandwidth using DDRx on this card over PCIe, to using DDRx in the standard memory sockets on a motherboard Edit: Looks like the slowest DDR4 gives 19200 MB/s https://uk.crucial.com/support/memory-speeds-compatability Not sure what PCIe that card supports is though
I haven't kept up with the speed and feeds, but in general PCI bandwidth is a decimal order of magnitude less than all the memory controller bandwidth
What is the competitive advantage of this versus NVMe? Their 1TB ramdisk is $1000, while a Gen 4 NVMe PCI-e card gives the same speeds in a smaller and more standard format for $150-$200.
Speaking as someone who actually runs NVMe RAIDs for large-ish databases, the NVMe speeds quoted are usually only attainable for large sequential streaming loads. While they are not spinning disks with heads that need to seek, there is still very substantial random I/O overhead with SSDs, including NVMe. Even with a top of the line model like a Samsung 980 Pro, you might only get 5% the PCIe 4 bus speed with heavy ra…
What is the competitive advantage of this versus NVMe? Their 1TB ramdisk is $1000, while a Gen 4 NVMe PCI-e card gives the same speeds in a smaller and more standard format for $150-$200.
Out of interest, would you get a similar bandwidth using DDRx on this card over PCIe, to using DDRx in the standard memory sockets on a motherboard Edit: Looks like the slowest DDR4 gives 19200 MB/s https://uk.crucial.com/support/memory-speeds-compatability Not sure what PCIe that card supports is though
Looks like the card is PCIe 4.0 x4, which gives about 8GB/s. Not sure if this board is driving the RAM at full speed, or how many controllers there are, but more lanes could make this faster.
This isn't a good device for most home users, but for businesses that cache a lot of high speed data this could be a useful tool.