RDSEED is actually what people want most of the time. RDRAND may return before sufficient entropy has been gathered.
Basically, RDRAND was made first to be something like a hardware /dev/urandom. Of course, people started using RDRAND to generate RSA-keys or whatever, but the entropy may be depleted between uses.
So you're supposed to use RDSEED whenever you need something that'd actually be truly random with a full set of entropy.
Basically, RDRAND was made first to be something like a hardware /dev/urandom. Of course, people started using RDRAND to generate RSA-keys or whatever, but the entropy may be depleted between uses.
So you're supposed to use RDSEED whenever you need something that'd actually be truly random with a full set of entropy.