Freeware RAM Disk software benchmark:

MB/s read, MB/s write:

Code:
SoftPerfect RAM Disk       3.4.8 (fat)         15,504.84 16,400.29
Ultra RAMDisk Lite         1.65 (fat)          15,399.50 16,077.85
PassMark OSMount           3.0.1006.0 (fat32)  14,271.84 18,171.73
ASUS ROG RAMDisk           unknown (unknown)   12,688.81 15,621.66
QILING Disk Master Free    5.1.0.0 (ntsf)      11,416.30 12,464.85
StarWind RAM Disk          5.6 (fat32)         11,367.45 16,222.78
Dataram RAMDisk            4.4.0.36 (fat)      11,255.26 15,969.61
Miray RAM Drive            1.1.0.0 (ntsf)      10,403.06 15,467.68
ImDisk Virtual Disk Driver 2.0.10 (fat)        10,398.57 15,922.14