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GPU vs. CPU Upgrade: Extensive Tests

What Advantages does Overclocking the CPU have for the Graphics Card?

The first table shows the gain in the overall results when an E2160 CPU is overclocked from 1.8 GHz to 2.41 GHz. The FSB is overclocked by 33%, pushing it from 200 to 267 MHz, which should be achievable using the stock cooler. The minimal increase in temperature is confirmed by the values for power consumption: the overall system with the overclocked E2160 requires between 6 and 10 watts (3D mode) more from the power supply.

Important! When attempting to overclock, you should always monitor temperatures carefully.

Performance increase of GPU by overclocking the E2160@1.8 to 2.41 GHzPercent
Geforce 9800 GTX (512 MB) E2160@2.41120.1
Geforce 9600 GT OC (1024 MB) E2160@2.41116.3
Geforce 8800 GTS OC (512 MB) E2160@2.41120.7
Geforce 8800 GT OC (512 MB) E2160@2.41116.5
Geforce 7950 GT (512 MB) E2160@2.41107.3
Geforce 6800 GT (256 MB) E2160@2.41100.6

With the new graphics chips, in particular, you can feel the effects of the higher clock rate more clearly: the 20% increased performance makes this obvious. Graphics cards with the G92 graphics chip need a basic performance level of at least 2.6 GHz.

When using the Q6600 things are a little more difficult: it is no longer a good idea to recommend a boxed standard cooler at 3200 MHz. The maximum power consumption or achievable clock rate varies from model to model: 3200 MHz was selected in order to leave some space to the X6800EE at 2.94 GHz, so that you can see from the comparison tables whether increasing the clock rate further will bring any more benefits. The FSB overclocking is 34%, and the base clock level 266 MHz is increased to 356 MHz.

Performance increase of GPU by overclocking the Q6600@2.4 to3.2 GHzPercent
Geforce 9800 GTX (512 MB) Q6600@3.2107.6
Geforce 9600 GT OC (1024 MB) Q6600@3.2105.8
Geforce 8800 GTS OC (512 MB) Q6600@3.2107.5
Geforce 8800 GT OC (512 MB) Q6600@3.2106.3
Geforce 7950 GT (512 MB) Q6600@3.2100.7
Geforce 6800 GT (256 MB) Q6600@3.2101.4

The performance increase due to an overclocked Q6600 is not as high in percentage terms as for the E2160. With a stock speed of 2400 MHz, the Q6600 achieved excellent results in the test games. In order for the quad core processor to keep up with the E6750, its clocking rate should be at least the same, lying between 2600 and 2800 MHz.

It’s important to remember that overclocking components will void your warranty, but that using adequate cooling and BIOS settings will help to assure component longevity. A Zalman 9700 LED has been used for this test: Questions about the appropriate BIOS settings can be answered in Toms Hardware Forums.

  • DjEaZy
    will there be a AMD/ATI roundup???
    Reply
  • randomizer
    That would simply consume more time without really proving much. I think sticking with a single manufacturer is fine, because you see the generation differences of cards and the performance gains compared to geting a new processor. You will see the same thing with ATI cards. Pop in an X800 and watch it crumble in the wake of a HD3870. There is no need to inlude ATI cards for the sake of this article.
    Reply
  • randomizer
    This has been a long needed article IMO. Now we can post links instead of coming up with simple explanations :D
    Reply
  • yadge
    I didn't realize the new gpus were actually that powerful. According to Toms charts, there is no gpu that can give me double the performance over my x1950 pro. But here, the 9600gt was getting 3 times the frames as the 7950gt(which is better than mine) on Call of Duty 4.

    Maybe there's something wrong with the charts. I don't know. But this makes me even more excited for when I upgrade in the near future.
    Reply
  • This article is biased from the beginning by using a reference graphics card from 2004 (6800GT) to a reference CPU from 2007 (E2140).

    Go back and use a Pentium 4 Prescott (2004) and then the basis of these percentage values on page 3 will actually mean something.
    Reply
  • randomizer
    yadgeI didn't realize the new gpus were actually that powerful. According to Toms charts, there is no gpu that can give me double the performance over my x1950 pro. But here, the 9600gt was getting 3 times the frames as the 7950gt(which is better than mine) on Call of Duty 4. Maybe there's something wrong with the charts. I don't know. But this makes me even more excited for when I upgrade in the near future.I upgraded my X1950 pro to a 9600GT. It was a fantastic upgrade.
    Reply
  • wh3resmycar
    scyThis article is biased from the beginning by using a reference graphics card from 2004 (6800GT) to a reference CPU from 2007 (E2140).
    maybe it is. but its relevant especially with those people who are stuck with those prescotts/6800gt. this article reveals an upgrade path nonetheless
    Reply
  • randomizer
    If they had used P4s there would be o many variables in this article that there would be no direction and that would make it pointless.
    Reply
  • JAYDEEJOHN
    Great article!!! It clears up many things. It finally shows proof that the best upgrade a gamer can make is a newer card. About the P4's, just take the clock rate and cut it in half, then compare (ok add 10%) heheh
    Reply
  • justjc
    I know randomizer thinks we would get the same results, but would it be possible to see just a small article showing if the same result is true for AMD processors and ATi graphics.
    Firstly we know that ATi and nVidia graphics doesn't calculate graphics in the same way, who knows perhaps an ATi card requiers more or less processorpower to work at full load, and if you look at Can you run it? for Crysis(only one I recall using) you will see the minimum needed AMD processor is slover than the minimum needed Core2, even in processor speed.
    So any chance of a small, or full scale, article throwing some ATi and AMD power into the mix?
    Reply