OverclockingThe overclocking results listed in this section were achieved with the default fan and voltage settings as defined in the VGA BIOS. Please note that every single sample overclocks differently, that's why our results here can only serve as a guideline for what you can expect from your card.
The maximum stable clocks of our card are 1170 MHz core (5% overclock) and 1870 MHz memory (25% overclock).
GPU overclocking potential is a bit lower than expected when compared to other enthusiast class GTX 680 cards; the difference is not that big though. Memory OC works very well and is among the best we have ever seen on a GTX 680.
|Maximum Overclock Comparison|
|Max. GPU Clock||Max. Memory Clock|
|POV GTX 680 TGT Ultra||1170 MHz||1870 MHz|
|KFA² GTX 680 OC||1240 MHz||1740 MHz|
|MSI GTX 680 Lightning||1225 MHz||1780 MHz|
|ASUS GTX 680 DC II||1207 MHz||1766 MHz|
|ZOTAC GTX 680 AMP||1130 MHz||1895 MHz|
|Palit GTX 680 JetStream||1165 MHz||1833 MHz|
|NVIDIA GTX 680||1147 MHz||1833 MHz|
Important: Each GPU (including each GPU of the same make and model)
will overclock slightly differently based on random production variances.
This table just serves to provide a list of typical overclocks for similar cards,
determined during TPU review.
Overclocked PerformanceUsing these clock frequencies, we ran a quick test of Battlefield 3 to evaluate the gains from overclocking.
Actual 3D performance gained from overclocking is 13.5%.
Memory UsageOur benchmarks show no visible improvement from 4 GB memory over a typical 2 GB GTX 680. That's why I decided to run an extra test using GPU-Z to record memory usage while running our test suite at 5760x1080 resolution.
As you can see, almost none of our games use more than 1.7 GB of memory with the exception of Battlefield 3, which still uses less than 2 GB, and Crysis 2, which peaks at 2287 MB - not even close to the 4 GB available. Our Crysis 2 installation uses the high-res texture pack and DX11 upgrade, which helps explain this reading.
However, in terms of actual performance numbers we see no significant improvement in Crysis 2 at that resolution. It seems that, even though the game uploads more than 2 GB in textures, it doesn't use them all which is why there is no visible performance advantage.
Now I hear you say "not so fast, what about 30" monitors?" The graph below shows three 30" monitors running in portrait mode at a resolution of 4800x2560.
We can clearly see an increased memory usage across all benchmarks. Again, Crysis 2 and Battlefield 3 are leading in memory consumption, but they are, still, not even close to using all the memory. AMD's Radeon HD 7900 Series comes with 3 GB of memory, which would be plenty, even for that scenario. At this resolution any single GPU card will just be too slow for serious gaming.
The order of benchmarks in the above tests is: Hard Reset, Stalker COP, Shogun 2, Civilization V, Sniper Elite V2, Crysis, Crysis 2, Batman Arkham City, Battleforge, Unigine Heaven, Battlefield 3, Skyrim, Dragon Age 2, Alan Wake, Max Payne 3, and WOW.