What is highest stable Memory Clock for an R9 270/270x

[Hound888]

So i recently started overclocking my card and i currently have it set to 1070Mhz core clock 1500Mhz Memory clock but i have heard more then a few people say you get a performance drop when overclocking the memory to 1500mhz is that true?

 

[amtseung]

Overclocking isn't an exact science. In fact, it's very far from an exact science. It's mostly luck, and the rest is trial and error and guesswork.

I had a reference pcb HD7950 that got as high as 1.3ghz core and 2ghz memory (8ghz effective) with an H55 zip tied to the GPU die and copper 1cm^2 heatsinks from amazon plastered all over the VRAM and VRMs. A fet gave out and popped anyway, but it ran at that OC 24/7 for a year and a half. Even though that fet has failed, the card still works, I just can't overvolt it, bringing its highest stable OC to 1.2ghz core and 1.8ghz memory. Some people I've seen could barely reach 1.1ghz core and 1.5ghz mem with a full coverage water block. I know the HD7950 became the R9 280, which has a slightly different architecture than the R9 270/X, but you get the idea.

If you haven't touched voltage at all, I'd say that's a pretty substantial OC regardless. I'd focus more on core clock than memory clock though unless you can push the core clock reeeaaaaally far, because that's where most of the gain is.

 

[Hound888]

Overclocking isn't an exact science. In fact, it's very far from an exact science. It's mostly luck, and the rest is trial and error and guesswork.

I had a reference pcb HD7950 that got as high as 1.3ghz core and 2ghz memory (8ghz effective) with an H55 zip tied to the GPU die and copper 1cm^2 heatsinks from amazon plastered all over the VRAM and VRMs. A fet gave out and popped anyway, but it ran at that OC 24/7 for a year and a half. Even though that fet has failed, the card still works, I just can't overvolt it, bringing its highest stable OC to 1.2ghz core and 1.8ghz memory. Some people I've seen could barely reach 1.1ghz core and 1.5ghz mem with a full coverage water block. I know the HD7950 became the R9 280, which has a slightly different architecture than the R9 270/X, but you get the idea.

If you haven't touched voltage at all, I'd say that's a pretty substantial OC regardless. I'd focus more on core clock than memory clock though unless you can push the core clock reeeaaaaally far, because that's where most of the gain is.

I have the non-x Version but this little thing can actually overclock more or the same as the X version. So ya my core clock of 1070 is quite modest considering i have seen people take both versions up to 1200mhz and its ability to keep cool with custom fan curve is insane, its original core clock was 975Mhz but at 1070 it only reaches 47c maxed out at 100% for hours. I just feel leery using the 1500mhz mem clock cause some people say it loses performance 1500 or over so i may drop it down to 1465Mhz or something just to be safe and then increase the core clock abit more.

 

[Hound888]

So i actually went through the pain of installing some free GPU benchmark software and from what i can see i am getting a few more fps at 1500Mhz vs 1400Mhz so 1500 must be running stable at least for my card...what would unstable look like anyway( i am abit new to overclocking)

 

[amtseung]

Unstable doesn't exactly look like anything. You usually know something is wrong when you don't see anything, like your screen going black, a BSOD, or if it starts randomly displaying rainbow tiles like a disco floor.

Trust me, you'll know when it's gone too far.

Or if you overclock and your fps starts dropping, then you're coming up against that limit.

I recommend any of the GPU stress tests/benchmarks from Unigine. Furmark/Kombustor are actually pretty good at breaking GPU's of that era. It broke two of mine, anyway.