Forget RAMDisks – Enthusiasts are turning AMD’s V-Cache into 182 GB/s storage

CACHEDisk? Ryzen 7 7800X3D user turns their V-Cache into an 182 GB/s RAMDisk

While modern PCIe 4.0 and PCIe 5.0 SSDs are more than fast enough for today’s tasks, there is always a drive to make storage faster and push the limits of PC technology. For years, PC users have used RAMDisk technology to create ultra-fast storage mediums, using system memory to create faster, albeit volatile, storage spaces. Now, Ryzen 7 7800X3D users are taking this concept to a new level by making a 3D V-Cache RAMDisk.

An X user called Nemez (via Tom’s Hardware) was the first to create a “CacheDisk” using an AMD Ryzen 7 7800X3D processor. Using very specific settings in CrystelDiskMark, Nemez was able to create a RAMDisk within the processor’s L3 V-cache. This allowed them to create a RAMDisk that could deliver insane 182GB/s performance levels within the SSD testing tool.

For context, today’s fastest PCIe 5.0 SSDs (like the Corsair MP700 PRO that we recently reviewed) typically deliver 12GB/s speeds in this test. That’s around 15x slower than this 3D V-Cache based RAMDisk. PCIe 5.0 storage may be fast, but it is nothing when compared to the speed of this RAMDisk.

CrystalCacheMark pic.twitter.com/MSGyrGkXv8

— Nemez (@GPUsAreMagic) February 13, 2023

It may not be practical, but this is what V-Cache RAMDisk performance looks like

Ok, ok. A RAMDisk this small is not that useful. However it does showcase the power fast caches and how they compare with DRAM or non-volatile system storage. Perhaps with V-Cache clad EPYC processors a more usable RAMDisk could be created. After all, AMD’s largest Genoa-X CPUs can feature over one gigabyte of L3 cache.

I don’t expect cache-based RAMDisks to become the next big thing for PC storage, simply because I do not see caches becoming large enough to become suitable for this purpose. AMD’s 96MB of L3 Cache on their Ryzen 7 5800X3D and Ryzen 7 7800X3D is already considered innovative. While AMD could add more cache to future CPUs, we do not expect to see large enough changes to make strange use cases like CacheDisk storage viable.

You can join the discussion on AMD’s V-Cache becoming an uber-fast storage medium on the OC3D Forums.

Have a Ryzen 7 5800X3D.
Install OSFMount and create a FAT32 formatted ramdisk.
Run CrystalDiskMark, set the test values to:
SEQ 256KB, Queue Depth 1, Threads 16
Set data fill to 0s instead of random.
Run the test (probably a few times, this is very sensitive to system load).

— Nemez (@GPUsAreMagic) February 14, 2023