For the longest time, game developers have been complaining about 32-bit limits for memory usage but were timid to cut off support for 32-bit OSes. It is one thing to tell users to drop a few extra sticks into their PC, as a handful of gigabytes have been pretty cheap for a while, but this barrier also required an OS upgrade, and many gamers were clinging to XP or fearful of driver problems. The problem has mostly been resolved for PC gamers now, and current consoles have crossed the threshold themselves with 8GB of memory (for Microsoft and Sony).
This brings us to Street Fighter V. I am not quite sure that a game like this inherently requires so much memory given the relatively few unique objects that fighting games tend to display. It apparently will be though, according to Capcom. Their official specifications claim that the game will not even launch without 6GB of memory installed, and 8GB is appreciated if it is available.
Otherwise, the game requires a dual-core (four thread) Haswell i3 at 3.6 GHz and an NVIDIA GTX 480 or higher. This is relatively high, slightly higher than Battlefield 3 in fact, but not too bad for today's situation. For the record, Capcom recommends a Devil's Canyon i5 with a GTX 960, but they naturally don't say what that corresponds to. They also don't provide AMD or Intel GPU equivalents, but I don't think even Iris Pro is equivalent so that probably just leaves Radeon users doing trial and error. Thankfully, Steam offers refunds just for that kind of thing.
They also want to say that Street Fighter V supports Steamworks. Expected, but nice.