Comment by JonChesterfield
3 years ago
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).
> 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.
That's the previous version with memory soldered on. There's no price listed for the one with DIMM slots.
However it turns out I was way out of date on nvme pricing. So that's awesome, if fairly bad news for this product.
I don't think you could buy fastest 2TB SSD for $280. More like $20'000 for 6TB.
Fastest SSDs are not Samsungs, ADatas, SunDisks or other "household" brands (yes, I know, that Samsung has enterprise models, without names, only with partnumbers, but even these models are not "fastest").
It is special brands, prices for which is not publicly available (or my google-fu is not strong enough).
Everything you buy for $280 will degrade when 75% full, and even sustained linear write will tank after first several tens of gigabytes, when SLC caches will be full. Not to mention random write with small blocks.
Special enterprise SSDs, like DataEngine T2HP, costs much, much more (and don't have 2TB models, looks like it starts from 4TB or even 6TB now, but still it is not like x2 or x3 to $280, it is more like x50).
On the other hand, one who could buy true enterprise SSD, will not buy this DDRamDisk from strange hobby-looking site :-)
> 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)
Do LiFePO4 instead. Nothing is fireproof but those are pretty tame.
> Do LiFePO4 instead. Nothing is fireproof but those are pretty tame.
The reason LiFePO4 is safer than higher voltage Liion is because it has less energy per volume. But even LiFePO4 can catch fire if punctured.[1] Although often incorrectly claimed to be, LiFePO4 secondary cells are not "intrinsically safe," like NiMH secondary cells are.
[1] https://www.youtube.com/watch?v=07BS6QY3wI8&t=3m17s