Originally Posted by ocyt
good info, thanks. my performace reflects this as well, 2149 (yes for whatever reason i stopped getting errors at 2149 after 2150 was, though i'll have to test it further to be sure)
and 1325 on the core with an undervolt.
but you brought up an interesting point, not exactly diminishing returns, but it gives literally no irl performance increase with the higher clocks.
think it's a driver issue? game devs being lazy? or is it like the 6870 being bios locked at 1ghz coreclock but per game performance being gimped...
what is your ASIC at?
ah that explains it, sorry for the confusion.
Well in all my years of experience, my theory about that, because this happens will all GPUs - AMD and Nvidia - It's when you check the FPS with a stock freq for example 1266 mhz, and then you rise the core to 1330 mhz, you are adding 64 mhz with no voltage or just a bit something like 0.015 v and probably you see a difference of 10 fps and that's very good, you can check benchmarks in the internet between for example Asus Strix with 1310 mhz stock or 1330 mhz in OC mode, and the reference card with 1266 mhz and you will notice a increment of 10 fps.-
But what happens next? and here comes the theory, when you past over the sweet point all the GPU have it, in the RX480 it's 1320/1330 mhz with 1.150v - The performance increase the some proportion with the freq BUT you need to add a lot of voltage and generate a lot of heat, and you start to see the lost of effiency, look my example:
1.100v = 1266 mhz
1.130v = 1320 mhz
1.180v = 1340 mhz
1.190v = 1350 mhz
Like you can see my sweet point it's 1320 mhz - So I have from 1266 mhz to 1320 mhz 54 mhz of dif and something like 10 fps - If I want 10 fps more, I will need another 54 mhz more, will be 1320+54 mhz = 1374 can be 1380 mhz ... I test it and I need = 1.220v
And start to have coil whine and a lot of not ideal situations - In basic you win performance with higher clocks but don't have effiency and start to be not productive.-
The ASIC it's a theory but apply very well, more high asic you can't rise too much voltage, but with less voltage from stock you can rise more higher clocks, low ASIC you can rise more voltage and you can rise more freq too, because it's not sensitive to the change of voltage, but you generate a lot of heat, that because for water cooling it's ideal low ASIC you can send a lot of voltage and control that, for air it's ideal high ASIC quality, less voltage, less heat.-
The ASIC it's directly related to the sweet point - I have a crossfire and one video card have from stock 1.150v (low ASIC) and the other 1.100v (high ASIC) from factory the same reference card.-
The high ASIC video card can just go to 1320 with nothing of voltage, but it's sensitive to add more, to get 1340 mhz I add voltage, all the time, and not win stability need to add a LOT (1.18v).-
The low ASIC video card can go to 1380 mhz and 1.170v every mv I add to the video card improve stability, but generate a lot of heat all the time.-
So my conclusion about the RX480 scale very very well with overclock, but just to 1320/1330 mhz then, it's a silicon lotery and the voltage will be very higher.-Edited by GecKoTDF - 1/17/17 at 6:19am