CryptGenRandom

In order to create a new volume initialized with random data, I just benchmarked the famous CryptGenRandom function. The function fills a 1MB buffer and is called several times. It works on one thread, on a Core i7 2600k @3800. Here are my results, for various systems running in virtual machines:
10 (64-bit) : 2160 MB/s
10 (32-bit) : 1550 MB/s
8.1 (64-bit) : 404 MB/s
8.1 (32-bit) : 392 MB/s
8 (64-bit) : 405 MB/s
8 (32-bit) : 394 MB/s
7 SP1 (64-bit) : 265 MB/s
7 SP1 (32-bit) : 163 MB/s
Vista (64-bit) : 37 MB/s
Vista (32-bit) : 30 MB/s
XP64 SP2 (64-bit) : 38 MB/s
XP64 SP2 (32-bit) : 33 MB/s
XP SP3 : 30 MB/s
XP : 24 MB/s

As we can see, newer is better. :)

But for very old systems, CryptGenRandom might be not suited to this situation. So I will have to find something else.