I've allocated 10GB of my 24GB RAM to the RAMdisk and ran CrystalDiskMark x64 v3.0.2f to see how fast it is.
- As recommended by the author, my Anti-Virus was disabled during the test.
- CrystalDiskMark was set to default (Random).
- ImDisk driver v1.7.5
- Kingston DDR3-1646Mhz @ 1.65V, 9-9-9-24-1T timings
- CPU is Intel Core i5-3570K @ 4.2GHz.
Here's the result (5x 1000MB):