Overclocking
This is my favorite part! First though, a disclaimer:
Overclocking means putting extra stress on your PC and it’s parts, it may cause damage to them, shorten their lifespan, and void their warranty.
Follow the methods in this article at your own risk!
Before overclocking the GPU I first overclocked my processor to 4ghz, it’s a nice round number and therefor the first target for anybody overclocking their CPU. It’s also a number that 99% of the Core i7 2600k and 2500k processors can reach easily, often without raising the voltage at all. While I’ve had this processor over 5.5ghz, that is not a level many can get to and doesn’t give a good example of benchmark results.
To overclock a video card you need some specialized software, my personal favorite is MSI Afterburner, despite being made by MSI it will overclock the vast majority of video cards and brands, it has a nice simple interface, and it generally places limits on the amount of voltage you can apply that will prevent you from frying your card. Be aware though: He (or she) who blindly sets the voltage slider as high as it will go is asking for trouble and dead hardware!
In the case of this Gigabyte Geforce GTX560OC the maximum voltage you can apply to the card is locked in bios at 1.08v or so, the stock voltage for this review card is 1.00 so this is an eight percent increase, and should be totally safe. As always, your mileage may vary!
Raising the voltage allowed me to overclock the core to over 1000mhz! It topped out at 1030mhz for 3dmark Vantage, though the maximum it could run varied by benchmark from 1030mhz down to 1010mhz. Still, that is a 21% increase over stock! Very good, much better than most cards.
The GDDR5 video ram topped out around 2200mhz. 10% faster than stock almost exactly.
Onward to the benchmark results:
3DMark Vantage
First with PhysX on:
Stock clocks score was 19870, so the overclock gained us 21% more performance, gotta love that!
Next with PhysX disabled:
Only 18.6% here, largely because of the CPU tests, the CPU wasn’t overclocked nearly as much as the GPU was. Still, 18.6% is a very nice bump in performance.
3DMark11:
Previous score was 4268, we’re up 19.7% here, this GPU is tearing it up!
Lost Planet 2:
As previously mentioned, this benchmark isn’t compatible with screenshots.
Overclocked, TestA scored 65FPS (A 22.4% increase!) and TestB scored 55.2FPS (a 20% increase).
22.4% is more than the GPU was overclocked! That’s my kind of response to OCing right there.
Unigine Heaven:
Remember when I said we’d see the real picture about Heaven and card performance when the card was overclocked? Well here’s that chart again, now that the card has scored a 1166 (A 17.9% gain):
Well now! This looks mighty promising. Not only did it eat the GTX560Ti cards (even the high-clocked versions) for lunch, it’s nipping at the heels of the GTX570! Keep in mind that the MSRP for the 570 is roughly 50% higher than this Gigabyte GTX560! This is part of why I like overclocking so much.
Temperature:
The last test is a functional test of the cooler, how hot does the GPU core run under full load?
The knowing the ambient temperature is critical to testing cooling performance, if you do not know the ambient temperature that the test was run at, the load temperature for the GPU is not very useful for evaluating heatsink performance. The core temperature itself is important as the GPU core does not like running over 90*c or so.
To make this a valid test, I dragged out my Fluke 51-1 K/J thermocouple temperature meter, Fluke is arguably the top name in thermocouple themometers, as well as in the voltmeter market.
The ambient temperature inside my case for these tests was 25.2*c, this is the number the GPU core’s temperature will be measured against.
I used Heaven to provide the load, as it is happy to run in a windowed format as well as being extremely demanding of the GPU.
With totally stock settings, the highest the GPU core temperature managed to get was 61.0*c, subtracting the 25.2*c ambient temperature gives us a total temperature gain of 35.8*c over ambient. Quite a good result, the GPU has plenty of room before it starts being unhappy, your ambient temperatures would have to be along the lines of high noon in the sahara before this GPU was unhappy.
Next I overclocked the card to 1000mhz core and 2200mhz ram, and fed it 1.087 volts. The ambient temperature was the same.
