There is a free "trial" offer to download the software, though the software appears to be the freeware version (without a time limit) of Ramdisk that is offered on Ramdisk's website, anyway.
However, there is a twist as those users who run AMD-branded memory can extended the virtual Ramdisk to 6 GB, instead of just 4 GB. If you want to go beyond 4 or 6 GB, you will have to purchase the personal version of the software, which is available for $19.
AMD promises that users could see a speedup of up to 1,700 percent when compared to HDD performance and achieve data transfer rates of up to 25,600 MB/s with DDR3-1600 memory. These are, of course, theoretical values.