AMD Radeon HD 7770 and 7750 Video Card ReviewsTue, Feb 14, 2012 - 11:00 PM
Overclocking The Radeon HD 7770
To overclock the AMD Radeon HD 7770 video card we again used AMD Overdrive to find the highest stable overclock without any voltage increases.
The AMD Radeon HD 7770 reference card comes clocked at 1000MHz on the core and 1125MHz on the memory. If you use CATALYST Control Center (CCC) like we did, you can raise or lower the clock frequencies within the parameters set by AMD. For this card AMD set limits for this particular BIOS to 1200MHz on the core and 1250MHz on the memory. We were able to run the card at 1075MHz on the core and 1250MHz on the memory without any stability issues. If we went up to 1080MHz on the core it would cause the game or benchmark to hard lock and we had to kill the application in task manager.
Here is a GPU-Z screenshot showing the overclock! This is a 75MHz overclock on the core and 125MHz on the GDDR5 memory.
Radeon HD 7770 at 1000MHz core and 1125MHz memory:
Radeon HD 7770 at 1075MHz core and 1250MHz memory:
We tried out this overclock with Futuremark 3DMark 11 on the performance preset and saw the score go from P3558 to P3780, which is a 6.2% or 222 3DMark point increase from the card’s stock settings. This isn’t a huge performance gain and, in all honesty, we were disappointed with it as the XFX Radeon HD 7770 that we had for testing was factory overclocked up to 1120MHz! It looks like XFX increased the cards voltages or we got stuck with a bad overclocker.
In Metro 2033 we went from 13.33 FPS to 14.33 FPS at 1920×1080 and 19.67 FPS to 20.67 FPS at 1280×1024. Not a huge improvement, but still a gain of 5-7% for free.
Next up we have the XFX Radeon HD 7770 Black Super Overclocked Edition featuring Dual Dissipation. This card is factory overclocked up to 1120MHz already, so it will be interesting what we can get this card up to. This card uses a different BIOS, so we can overclock it up to 1350MHz on both the core and memory clocks.
We weren’t able to get the XFX card much higher than the default settings, but we were able to get another 35MHz on the core and 50MHz on the memory. This puts the core clock at 1155MHz, which is 155MHz over a stock Radeon HD 7770.
XFX Radeon HD 7770 at 1120MHz core and 1300MHz memory:
XFX Radeon HD 7770 at 1155MHz core and 1350MHz memory:
We tried out this overclock with Futuremark 3DMark 11 on the
performance preset and saw the score go from P3891 to P4029, which is a 3.5% or 138 3DMark point increase from the card’s stock settings. Not a huge overclock, but we did break the 4,000 point mark in 3DMark11 and that is nice to see.
In Metro 2033 we went from 15.00 FPS to 15.33 FPS at 1920×1080 and 21.33 FPS to 22.00 FPS at 1280×1024.
It appears that AMD already aggressively set the core clocks on the AMD Radeon HD 7700 series, so overclock doesn’t look like it will be too fun!