Prime 95 one core is slower

Is it normal to have one core that is slower than the others and fails first.

Lately I've been trying to overclock my cpu and when I've been testing my computer with prime95 I've noticed that one of the cores is failing first,

I'm overlcoking an 8320.

8320 and 8350 that is pretty normal to see. weaker cores, they are always the problem children when overclocking AMD FX CPUs

I've got an 8350 and I find that a couple of mine are usually a bit slower, and always fail first. It's not an issue with your cpu, It's likely just the nature of the heat dispersion or power delivery. That being said If any are failing then your oc isn't stable. If any are reporting as being a lot slower, or are failing, you've got some tweaking to do. I've gotten my 8350 up to 4.5Ghz being fairly stable with a hyper 212. When bench-marking, I believe it's core 5 or 6 that goes out after about 30 minutes. I'm sure if I was better at ocing and had more patience I could fix it but It's not worth the trouble, I run my system at stock speeds.

Keep in mind that when stress testing with prime 95, the CPU is still needed to run the OS and what ever running process you may have in the background. Other than that, with the FX CPU's due to the shared resources, e.g., http://www.extremetech.com/computing/138394-amds-fx-8350-analyzed-does-piledriver-deliver-where-bulldozer-fell-short/2

 

FX chips get the largest performance drop is core "cores" on one module are trying to perform the same task, as they both begin to fight over the same exact resources while a dissimilar load may have less of a performance drop because fewer components will be shared, so a background process taking CPU time from prime 95 on a couple of the cores, may make the other core in the same module effectively perform faster, or the background process may make the core d something that stresses another component which carries a larger overall performance penalty.