Yes. Basically the highest number a 32 bit system can deal with is 2^32 which is 4gb. So if that system had an 8gb ram stock it could not store a number large enough to addresses the spots after the 4th Gb.
And a 64 bit system can use anything from 0 to 2^64
A 32-bit processor uses addresses that are 32 bits long. There are only 4,294,967,296, or 4GB, possible 32-bit addresses.
You need 4gb ram minimum because they are dropping support for 32 bit computers, only 64 bit stuff. Not related to Direct X stuff
But, like, a 64 bit processor can still use RAM less than 4GB? It's just that a 32 bit CPU can't address more than 4gb?
Yes. Basically the highest number a 32 bit system can deal with is 2^32 which is 4gb. So if that system had an 8gb ram stock it could not store a number large enough to addresses the spots after the 4th Gb.
And a 64 bit system can use anything from 0 to 2^64
https://www.pcworld.com/article/2013751/why-cant-32-bit-windows-access-4gb-of-ram.html