We present our overclocking scaling results in a different manner than we normally do. As you know, we very much like to graph the actual scaling in terms of performance or overclockability using an extensive series of tests from a more scientific point of view. However, this time we opted for a very small comparison of four stages of the overclocking proces:C2D - Stock
Ci7 - Stock
Ci7 - OC
Ci7 - Voltage increase
The Core 2 Duo results you’ll see is the same data we used in our 9500GT review a few months ago. Although this means that they are not entirely comparable, we wanted to give them anyway for to see how it compares to the more recent Core i7 setup. Obviously, the i7 is a winner in the 3DMark06 and 3DMark Vantage benchmarks, due to the 4 cores and hyper threading technology.
Below you find a table of the clock frequencies used in the different test cases. Note that the frequencies can be a little bit higher or lower depending on what benchmark we were running; after all, 3DMark06 stresses the video card more than others, like Aquamark3.
On stock voltage, we were able to push the Galaxy to 750/1800/1134Mhz without too much trouble, but to go further up, we were in need of voltage modifications. At first, we only modified the Vgpu, since 1.1GHz memory frequency is more than enough to feed the video card (which is limited by the core and shader clocks). However, as we more or less expected, we were unable to clock the memory up to 1.1GHz anymore after we increase the Vgpu to 1.35v. Even at the stock frequency of 1GHz, we found the card to be very unstable! This is a known issue with a lot of Gefore 9 series products: when increasing the Vgpu (and GPU frequencies), you need to increase the memory voltage to keep the card stable. Once we increase the memory voltage to 2.1v, we were again able to run at 1.13GHz.
Since we have no other cooling solution available than the Galaxy stock cooling, we did experience heat issues above 1.45v. However, at 1.45v, we had almost no heat issues, which is very impressive for just stock cooling! Let's have a look at the scores:
For reference, here are the links to the final scores:
3DMark01: 65200 - 3rd
3DMark03: 29234 - 2nd
3DMark05: 18727 - 1st
3DMark06: 9521 - 2nd
3DMark Vantage: 3595 - 1st
Aquamark 3: 233037 - 3rd
As you can see, we managed to hit top3 in each benchmark only using the stock cooling, which makes us wonder what will happen when we bring out the LN2, that’s a story for later on :-)
Overclocking too far: artifacts
While overclocking to the brink of stability does lead to impressive scores, it doesn’t mean your system is usable at those speeds, to illustrate this, take a look at the following two recordings made during the bench session; if you are into flashy colors, overclocking your VGA could be your thing ;-)