Hello all i am getting into overclocking my system and i am currently at my GPU (i suppose i also have a question regarding my CPU OC and how it potentially is affecting my GPU performance). I have the Asus R9 280x which comes with a core clock of 1070mhz and a stock voltage (atleast when i went into GPU Tweak) of 1138mV. I tried to determine what would be a good safish voltage to set my 280x to and after some searching i came to the conclusion 1.2 would be a good starting point, i set the voltage and then started raising my GPU clock first to 1080 and then from their i increased it 20mhz every time, i got to 1140 and that was all fine and dandy it seemed when i was testing it in the Valley benchmark and in BF4 and BF3, played those for awhile without any artificats that i could notice and no crashes, my temps would sit around 74C when i was testing these games without any kind of FPS cap and was just letting it go full load. After that i decided i would stick with that for awhile.
Today though i went and played bad company 2 with aforementioned overclock, not testing the OC just playing the game normally, i had a FPS cap so i wasent stressing my GPU in anyway really, at most i was hitting 55% GPU usage playing at max settings. Then all of a sudden my game froze which i thought was weird. So i went back into the game but this time uncapped my FPS and tried to stress the card and it pushed it to the 88%-99% range then after 10-15 minutes of doing that my whole system froze and my speakers started buzzing, i had to hold in the power button to restart to resolve this.
My question is, is that normal for seemingly more demanding games to work perfectly fine with a OC but a older less demanding game not work fine? The next question is should i raise my voltage in this situation? and i couldent really find a clear answer to this with my research but could somebody possibly explain what the power target is for and if increasing that would assist me in my OC?
Now back to the question i stated at the beginning regarding my CPU OC, I got my i5 4670k to 4.2ghz, during most games it never pushes it past 50-55C and i was pretty content with the OC and it didnt really want to deal with trying to push it further. After watching linus's video on haswell OCing i set my CPU to adaptive voltage so when one the desktop completly idle it will go as low as 800mhz and then in intensive tasks like games it boosts up. At first i started monitoring this and noticed ever in games it would not boost up to and stay at my specificed 4.2 frequency, it jumps about from 3.9ghz-4.2ghz.
Now with that out of the way before i started OCing my GPU, i was just monitoring my CPU and GPU usage and temps while playing BF4 and BF3, while playing these games at a uncapped FPS i noticed that randomly during gameplay my GPU usage would drop from the high 90%'s down to low 80%'s which from my understanding would imply my CPU was maxing out in usage and therefore my GPU was being slowed down, in these occurrences though my CPU usage was not at 100% so unless there is something im missing there. My question is that issue im having possibly related to my CPU frequency jumping around that 300mhz or is it something else?
I know this has been a long post and im not that good at condensing things down so pardon me. Thanks in advance to anyone who can help me out on this.