Plus, Windows does a reasonable job of caching games and other frequently accessed applications into RAM in the first place (it's one reason why reloading a level is often faster the second time you do it). That sort of defeats the purpose of a fast storage solution in the first place.

For a 50GB game, that could mean several minutes of waiting at HDD speeds, or maybe only 10-20 seconds with a fast M.2 SSD. After loading Windows, you have to load the RAM disk utility and then copy over all the files you want on fast storage to the RAM drive. That also means it takes longer to get everything ready in the first place, and you can't really use a RAM disk for the OS. You have to copy all the important data from your RAM disk to your actual SSD or HDD before turning off your machine or else everything on the RAM disk gets erased. Furthermore, you would never be able to shut your computer off (only power it down in sleep or hibernation mode) because you can't actually store anything on the RAM itself. You can 'save' files to the portion of RAM you designate as storage space, but if your computer crashes due to a power loss, you lose those files.

All the processing of the file contents is a bigger bottleneck. It's why most SSDs might at best cut load times in half, depending on the game, and why M.2 SSDs don't load games significantly faster than SATA SSDs. Reading the files off your storage device is only part of the task of loading a game. That doesn't mean games would load immediately, however. You would see near-instant file read and write times. So, if you need a lightening-fast virtual drive for whatever reason, a RAM Disk would be the way to go.

In comparison, the fastest available consumer SSDs, like the Sabrent Rocket, have a max transfer rate of 5,000MB/s. A single stick of RAM operating at 2666 MT/s (megatransfers per second) is the equivalent of 21,328 MB/s (megabytes per second) or 21.328 GB/s.

Softperfect ram disk limit