What is factual fastest speed you can get and how does it compare to RAM disk?

[kamamam]

Imagine I'm a multimillionaire and want to create a server with fastest read/write speeds possible.

I imagine I could use a lot of RAID 0's PCIe SSDs, but of course these don't stack forever, there's a practical limit to it's speed.

Considering I could hire a specialist do it for me, what is a practical first speed limit I would reach and how would it compare to RAM?

The other way to ask this question is what combination of setup and commercially accessible hardware (excl. RAM) would I need to reach possible peak read/write speed and how would that compare to a RAM disk?

 

It's theoretically-practically speaking. Theoretically USB 3.0 is insanely fast, until you use it, practical reality looks different and theoretical maximum is never reached.

Same applies to this question, what is a theoretical maximum that you can reach in actual practicality?

[Crunchy Dragon]

RAM is one of the fastest buses in an entire system, I don't know if much can actually top it.

 

That said, anything you load into RAM will be lost in the event of losing power(either by shutdown or power outage).

[kamamam]

4 minutes ago, Crunchy Dragon said:

That said, anything you load into RAM will be lost in the event of losing power(either by shutdown or power outage).

Guessed as much, but I think more of a redundant storage.

[Jurrunio]

Max speed depends on how many PCIe lanes the CPU has. 9600k for example, has 16 PCIe lanes to the PCIe slot and 4 to the chipset. with appropriate expansion cards you can have 5 PCIe 3.0 x4 SSDs running at their max speed (assume 3000MB/s), put them in RAID and you can expect some 15000-16000MB/s speed in theory (in practice, likely lower)

 

RAM however... Even 2666MHz dual channel kit can easily do about twice that (theoretical max is 42656MB/s, you'll never reach that).

 

If you're a millionaire and buy an 8 channel Eypc running 3200MHz memory, you'll get a theoretical max of 200GB/s (more like 150GB/s in practice), while 128 PCIe 4.0 lanes gives 246GB/s worth of bandwidth, assuming 6000MB/s per SSD (I dont see any drives on the market that can do that, let's say you can source server material) then it could still do 192GB/s which is barely slower than the max of RAM.

[Jurrunio]

3 minutes ago, kamamam said:

but I think more of a redundant storage.

It's definitely not a good redudant storage when it forgets everything after a shutdown

[GrockleTD]

@Jurrunio what about HBM2 VRamdisks? /s

[kamamam]

2 minutes ago, GrockleTD said:

@Jurrunio what about HBM2 VRamdisks? /s

 

Doesn't HBM2 drop memory just like RAM does during power outage?

Isn't HBM2 to GPU what RAM is to CPU (technically L1 cache, but still)?

[GrockleTD]

7 minutes ago, kamamam said:

 

Doesn't HBM2 drop memory just like RAM does during power outage?

Isn't HBM2 to GPU what RAM is to CPU (technically L1 cache, but still)?

Yes, I was just joking about maximum bandwidth achievable

[Jurrunio]

2 hours ago, GrockleTD said:

@Jurrunio what about HBM2 VRamdisks? /s

You're still limited by the PCIe bus though