Use of NVMe RAID-0 for ECC RAM extender?

[cbn]

How well could multiple M.2 NVMe SSDs in RAID-0 (example here) work as a "system RAM extender"? (Specifically ECC System RAM)

How does the error checking on various M.2 NVMe SSDs compare to ECC UDIMMs or ECC RDIMMs?

I'm thinking it might work well enough at least with certain SSDs (Re: The Radeon SSG has a two Samung 950 Pro M.2 NVMe on it in RAID-0 (This in addition to 16GB ECC HBM2) for large data sets):

https://www.anandtech.com/show/10518/amd-announces-radeon-pro-ssg-fiji-with-m2-ssds-onboard

https://www.amd.com/Documents/Radeon-Pro-SSG-Technical-Brief.pdf

 

[cbn]

The following is an article on using Intel Optane as Memory Extender for Xeon processors (using Memory drive found on the chip):

http://www.zdnet.com/article/optane-ssd-fast-enough-to-be-used-as-memory-extender-intel/

https://www.intel.com/content/www/us/en/solid-state-drives/optane-ssd-dc-p4800x-mdt-brief.html

Intel® Memory Drive Technology is a revolutionary software that extends system memory transparently. Combined with an Intel® Optane™ Solid State Drive (SSD), Intel® Memory Drive Technology transparently integrates the SSD into the memory subsystem and makes it appear like DRAM to the OS and applications. Intel® Memory Drive Technology increases memory capacity beyond DRAM limitations and delivers DRAM-like performance in a completely transparent manner to the operating system and application. In addition, no changes are required to the OS or applications.

There are two key scenarios in which it is beneficial for an IT environment to use Intel® Memory Drive Technology:

• Displace a portion of DRAM to reduce overall memory cost
• Grow the memory pool beyond DRAM capacities when large system memory is required.

 

[cbn]

One reason I am asking if because the AMD X399 platform (Threadripper CPU) released bootable NVMe RAID 0, 1 and 10 yesterday:

https://www.anandtech.com/show/11892/amd-launches-nvme-raid-support-for-ryzen-threadripper-platform

And eventually I suspect this technology would even filter down to some future version of Socket AM4 (considering one Zeppelin die is actually capable of 32 PCIe 3.0 lanes). So when that happens we could have a card like this in a PCIe x16 slot and a video card in a PCIe x 16 slot (running x8). Such a combination (or perhaps even a Workstation APU with 1/2 rate Double precision floating point) would make a for interesting (and capable) little workstation.

 

[Billy Tallis]

Most SSDs these days, especially NVMe SSDs, have very robust error correction on the NAND side. End-to-end data protection isn't universal, but is available on some consumer-grade SSDs, so you can also have ECC on the controller's DRAM and SRAM. I'm not sure off the top of my head how well consumer platforms handle PCIe bus errors, but the standard does have rich error handling capabilities. Overall, a quality NVMe SSD is a fine choice for a reliable swap device. The problem is that even the best flash-based NVMe SSDs are still limited by the fundamental read latency of NAND flash. That's why Optane is so interesting as a swap drive: https://www.anandtech.com/bench/SSD17/1895

 

[cbn]

Thank you.