Practical RAMDISK pc

[Rendawg87]

I had an interesting idea. I do not think ram requires much power to stay refreshed. Given battery tech now, would it be possible to build a small battery pack unit to keep ram refreshed on a ramdisk PCI Express card? Given how cheap ram is I bet you could build a desktop with 128 GB of constantly refreshed RAMDISK that you could install an OS on. 

 

I sure hope ramdisk pci express cards are still a thing. 

 

I'm also a huge fan Linus! I'm your age and I relate to your experiences with technology and love for it. (It's funny and really crazy

to see your younger associates not understand certain old school tech terms or hardware). You keep me loving Tech like a kid again even when my career makes it a drag. Much love!

[Streetguru]

11 minutes ago, Rendawg87 said:

 

PCi-e isn't really suited for the speed that RAM runs at anyways.

 

Top NVME drives are comparable in speed now, especially in a RAID 0 set up

[Mira Yurizaki]

PCIe 3.0 x16 tops out at ~16GB. DDR4-2166 is about 17 GB/s. So there's a bandwidth issue there.

[Bitter]

I seem to recall technology similar to this or exactly this from a number of years back, problem was it was eclipsed in capacity and cost by flash memory storage, the trade in speed was worth the gain in cost/gb of storage and now with NVME it's fairly moot since you're still pushing over the same PCI-e lanes so latency isn't that much better anymore. If you have a bunch of memory you can cache a ton of stuff to RAM and it does go faster but on modern systems the perceived gains are very small.

 

My personal experiences were back when I had XP 64bit *shudder* running on a system with 4GB of RAM and using a RAID0 array of two fast 7200 RPM hard drives, latency on the array was still not great even if sustained speeds were good for the time. I cached my browser disk cache into RAM with a virtual RAM disk software, that made going forward and backward instant, I cached some Windows OS assets into RAM as well, made Windows feel really fast and slick. I cached anything I could, felt great. Then I got an SSD and I couldn't feel that speed gain anymore over the SSD. On a modern system with SSD or NVME storage the gains you can notice from caching to RAM are far smaller, certain things may see a nice bump but mostly you won't notice.

[Rendawg87]

Yes the total size of the pipe might be an issue, but the speed at which the data is accessed and sent is far far faster than any NVME drive could access it's data. 

[Radium_Angel]

24 minutes ago, Rendawg87 said:

I had an interesting idea. I do not think ram requires much power to stay refreshed. Given battery tech now, would it be possible to build a small battery pack unit to keep ram refreshed on a ramdisk PCI Express card? Given how cheap ram is I bet you could build a desktop with 128 GB of constantly refreshed RAMDISK that you could install an OS on. 

 

I sure hope ramdisk pci express cards are still a thing. 

 

I'm also a huge fan Linus! I'm your age and I relate to your experiences with technology and love for it. (It's funny and really crazy

to see your younger associates not understand certain old school tech terms or hardware). You keep me loving Tech like a kid again even when my career makes it a drag. Much love!

So built it, blog it, video it, and let us know how it works (or doesn't work) I like ideas like this, something different from the usual RGB OC'd stuff we see daily.

[Bitter]

2 minutes ago, Rendawg87 said:

Yes the total size of the pipe might be an issue, but the speed at which the data is accessed and sent is far far faster than any NVME drive could access it's data. 

Not really, you'd still be limited by the latency in the PCI-e system vs the IMC and RAM which is MUCH lower latency. Say RAM via the IMC has a 60ns round trip, well in a PCI-e slot it's not going to be 60ns round trip. From what cursory data I'm seeing on Google it's about 10x higher on the PCI-e data buss vs RAM, so 600-900ns latency. Again though, we're talking things that just are not able to be perceived to the end user. Maybe doing a data intensive task over a long period of time those little bits would add up but still the cost/GB doesn't really pan out. Using software to cache writes to RAM for later writing is a better use of your system memory or the speculatively cache data to be read even, I do that with the Samsung software for the SSD in my HTPC and it works seamlessly for small writes and reads things happen with apparent instantaneous speed, even on computers where I'm not using any RAM caching just having a SSD makes things happen pretty darn fast. Theory is great but practical application isn't so practical.

[Rendawg87]

Fair point. If that's the case then the end result not only is not really noticeable but the limits to pci express make it a lost cause in the sense I'm looking at it in. 

[Snipergod87]

RAM with battery backups are a thing, but only in the enterprise space.

[Steven123123]

is this the same performance as what live linux cds do when they boot to ram?