The RAM disk on AMD 3D V-Cache is 12 times faster than the fastest PCIe 5.0 SSDs

Sam Berens
27 November 2023 11:19

A RAM disk is a technology that makes it possible to use the computer’s working memory as a storage medium. This has the advantage that the speed is higher than the average hard drive or even SSD, but the latency can also be very low. However, since the rise of PCIe SSD, the technology offers fewer advantages than before. However, the losses are the same as before; RAM memory is more expensive, smaller, and more volatile.

However, now there is An interesting picture emerged from CrystalDiskMark in which a reading speed of no less than 182 GB / s and a writing speed of 175 GB / s were obtained. This turns out to be the RAM disk running on the 3D V-Cache of the Ryzen 7 5800X3D. To achieve this, very specific settings are required with the OSFMount utility in which the RAM disk can be created. Test values ​​must be set to SEQ 256KB, queue depth to 1 and chains to 16. Data size must also be set to zero instead of random. Even with this preparation, good results are not guaranteed, because the system also uses the L3 cache in the background, which can significantly affect the results.

There seems to be no practical benefit for this use of AMD’s 3D V-Cache and the values ​​obtained are not even close to the actual bandwidth of 3D V-Cache, which is 2 TB/s for the Ryzen 5000 series and even. to 2.5 TB/s for the Ryzen 7000 series. There may still be some value to be gained from using L3 cache as a RAM disk for AMD EPYC processors, as these have 1.3 GB of L3 Cache, which can make the disk RAM makes it more interesting.

Source:
Tom’s equipment