Guys,
I have a quick question related to RAM speed, and wow. I have a hobby of building PCs, my current challenge is to build an older machine that can run wow. I would like to play both classic and BFA. I have chosen an adequate CPU and GPU. My question would be, do I pick 1066 mhz ram or 1333 mhz ram. I have to pick from these, both would be 8 gigs. (I am aware that ram speeds shouldnt make much of a difference, but we are talking about pretty slow ram right now, compared to modern standards.)
Thanks for the input
RAM speed advantage depends on rest of your computer (CPU mainly) as eg. current generation AMD CPUs like faster RAM more than Intel’s CPUs.
So answering to your question is impossible without knowing rest of computer parts you have chosen, but judging by the speeds you mentioned they are older DDR3 and old CPU so speeds probably won’t give huge differences but I would pick the faster regardless.
The answer is based on CPU being Intel CPU as AMD CPUs of that era (Bulldozer) are totally outclassed by even older Intel CPUs so buying them at this point would not be very good idea.
Grelier pretty much nails it here. 
The actual difference between 1066 and 1333mhz DDR3 is not all that great, if there is a performance bottleneck it will likely indeed be on the CPU itself - but there is really no imaginable benefit in going for slower memory if you have a faster option available. 