DDRamDisk: RAM disk, a disk based on RAM memory chips

Also some early general-purpose microcomputer products in early '80s:

http://s100computers.com/Hardware%20Folder/SemiDisk/History/...

http://s100computers.com/Hardware%20Folder/Electralogics/His...

An interesting quirk of the later designs is they're bring your own ram. That might be a worthwhile thing to do with a pile of DDR3 from an old server. I think I've got 256gb or so in a draw somewhere that's otherwise unlikely to see any use.

Lithium battery strapped to consumer chips - so you can basically ignore the volatility aspect (possibly in exchange for an exciting new fire risk, not sure how professionally built these things are). That might be objectively better than a pci-e ssd, at least in terms of performance (particularly performance over time).

Interesting design. They use FPGAs to emulate NAND storage with DDR, then use a standard NAND SSD controller.

It doesn't perform any better than fast NVMe SSDs for larger, sequential operations. However, it appears to be an order of magnitude faster for the random 1K read/write operations.

It also has infinite durability relative to an SSD, though obviously your data isn't infinitely durable during a power outage scenario. Would be helpful to know how long that battery can keep it backed up.

> An interesting quirk of the later designs is they're bring your own ram. That might be a worthwhile thing to do with a pile of DDR3 from an old server. I think I've got 256gb or so in a draw somewhere that's otherwise unlikely to see any use.

The 256GB version is listed at $280. That's more than enough to buy the fastest 2TB SSDs on the market which will match the performance of this device for most real-world workloads.

Now that SSDs have become so fast, RAM disks really only help with very specific workloads: Anything with a massive number of small writes or anything that needs extreme durability.

These could be useful for certain distributed computing and datacenter applications where constant drive writes would wear out normal SSDs too fast.

For most people, buying the card just to make use of some old DIMMs would cost a lot of money for virtually zero real-world performance gain. Modern NVMe SSDs are very fast and it's rare to find a workload that has extreme levels of random writes.

> I wouldn't take a precious M.2 SSD slot on my main machine for 5-year old 1Tb drive, but I'd love to chuck 8 or 10 of them in some enclosure and build a nice performant NAS out of them. Alas, no such thing exists

NVMe M.2 drives can go into PCIe slots with an adapter.

If your motherboard supports bifurcation, you even put 4 x M.2 drives into a single x16 slot: https://www.amazon.com/Adapter-4x32Gbps-Individual-Indicator...

It wouldn't be difficult to find an older server motherboard with bifurcation support that could take 8 x M.2 drives with the right, cheap adapters. You'd have to read the manuals very carefully though.

The limit is the number of PCIe channels. ARM boards rarely have more than a couple lanes. You really need server-grade chips with a lot of I/O.

Or get one of the new cards with a PCIe Switch to connect 21 M.2 drives: https://www.apexstoragedesign.com/apexstoragex21