Performance Testing Part 2: Overclocked
WARNING: Overclocking your computer can void the warranty on the entire computer, as well as causing damage to various parts of it. This can be as extreme as small explosions and fire in certain, rare, circumstances.
Overclocking Nvidia’s latest series of cards is very different than previous cards, rather than telling the card to run at X MHz you tell the card to run X MHz faster than it would otherwise run at. Same for voltage, memory clock and overall TDP levels.
I tested out Gigabyte’s OC Guru 2 software and found it to be dubious at best. It looks quite snazzy but there are no sliders, only up/down buttons. Worse there are arbitrary limits on where things can be set, and they are not Nvidia’s limits (as evidenced by other software happily going higher). All in all, it needs some work. On the plus side, other OCing software works with the card just fine.
The most the card’s core wanted to OC was +70MHz, it did that with +80mV and 115% power. The memory on the other hand was happy to run faster, it was quite happy at +300MHz. The memory OC and the +70MHz to the core help, but the biggest difference sems to come from the power slider. Watching the GPUz sensors page, it doesn’t look like the +mV atually does anything.
The GTX 6xx series cards overclock themselves automatically based on temperature, load and current draw. With the power limit raised 15% the card stays in overclocked mode much more of the time and does so through heavier loads as well. In the following results you’ll see what I mean. Interestingly different speeds are reported in difference places, the GPUz main window shows the base levels for normal and boost speed, while the sensors page shows current clock speeds. At +70MHz +80mV and 115% power the core speed was actually hitting ~1300MHz, rather more than 70MHz above the official boost level of 1111MHz!
For this testing my 3770k CPU was overclocked to 4.5GHz. A number that 99% of modern Intel K series CPUs should be able to reach easily on decent air cooling.
Here we have the GPUz pages just after a 3DMark11 run:
The main page reflects the base targets, while the sensor page shows the reality, roughly speaking.
The memory clock reading is from after the benchmark when the card returned to idle, I moved the cursor back on the core clock to show where it was actually running, 1310MHz! Same for the core voltage (VDDC), it runs at 1.175v when in turbo-load mode.
The highest temperatures I saw from the card overclocked was 69c with auto fans. This is a very good cooler. The fans make a bit of noise in the 75-95% range, but under that they are very, very quiet. That 69c comes at around 60%. Onward to the benchmarks!
3DMark03
The entire GTX600 series doesn’t really like 3D03, I expect it’s because it’s a rather old version of directx. Not that averaging a minimum of 718FPS is bad mind you!
3DMark Vantage
First up, with Physx enabled:
I call going from 36k to 40k a meaningful improvement.
Non-Physx:
Interstingly, from 30k to 34k is about the same increase. I didn’t see that coming. It stomps the 7870 into the ground and is right on par with an overclocked 7950. Impressive.
3DMark11
That’s a healthy increase right there. That beats a stock GTX670 and beats some configurations of GTX680 as well. Hard to argue with this card when it does that! Admittedly a GTX680 with a 3770k does score higher than this, but it also costs a lot more. It stomps a seriously overclocked 7870 into the ground, easily. It also beats the 7950 handily in anything that involves tessellation, even OC’d.
HWBot Unigine Heaven
First up, DirectX 11:
Again, OCing a bit gave a big improvement.
DirectX 9:
This is serious territory! We’re over many GTX670 results here and close to the GTX680. Nvidia and Gigabyte may have done too good of a job.
Game benchmark time! We’re skipping Skyrim. It capped out stock, it’ll cap out OC’d too.
S.T.A.K.E.R. Call of Pripyat
Here we are in the nuclear wasteland (is it still a wasteland if there’s too much life?), with some benchmark results:
Right around 10% faster across the board. How much is due to the power being set to 115% and how much is due to the +60MHz is hard to say.
Battlefield3
I played the same map on the same settings with the same number of people (and my team even won again!) so as to keep the variables to a minimum, here’re the FPS:
Bare minimum was 62FPs! Beautiful. The game really looks quite nice as well.
All told, it is definitely worthwhile to OC this card. The temperatures don’t change much, the lifespan should be unchanged (should…) if you don’t push too far, and the performance increase is very impressive!
