CPU Power for the Graphics Cards
In this comparison, you can see the increase in the overall 3D performance as the CPU performance increasesThe E2160 at 1800MHz sets the reference point for percentage increases: A rating of 120% for example is only 20% faster than this reference point. The percentage value is calculated using the overall result achieved in the benchmark suite at all tested resolutions, by a combination of graphics card and CPU.
| Performance increase of 9800 GTX by means of CPU | Percent |
|---|---|
| Geforce 9800 GTX (512 MB) E2160@1.8 | 100.0 |
| Geforce 9800 GTX (512 MB) E2160@2.41 | 120.1 |
| Geforce 9800 GTX (512 MB) E6750@2.67 | 137.9 |
| Geforce 9800 GTX (512 MB) Q6600@2.4 | 132.8 |
| Geforce 9800 GTX (512 MB) Q6600@3.2 | 143.0 |
| Geforce 9800 GTX (512 MB) X6800EE@2.94 | 139.0 |
The Geforce 9800 GTX responds very well to the clocking speed and performance class of the CPU. Overclocking the FSB by 33% on the E2160 results in 20% more performance overall for the Geforce 9800 GTX. There is only a difference of 2% to 7% among the E6750, the Q6600 standard rate and the X6800EE.
| Performance increase of 8800 GTS 512 OC by means of CPU | Percent |
|---|---|
| Geforce 8800 GTS OC (512 MB) E2160@1.8 | 100.0 |
| Geforce 8800 GTS OC (512 MB) E2160@2.41 | 120.7 |
| Geforce 8800 GTS OC (512 MB) E6750@2.67 | 140.5 |
| Geforce 8800 GTS OC (512 MB) Q6600@2.4 | 135.4 |
| Geforce 8800 GTS OC (512 MB) Q6600@3.2 | 145.6 |
| Geforce 8800 GTS OC (512 MB) X6800EE@2.94 | 142.6 |
The Geforce 8800 GTS OC responds even better to the CPU performance, thanks to the higher clocking rates for shader and GPU. A weaker and lower clocked CPU wastes at least 35% of overall 3D performance with the G92 graphics chip.
| Performance increase of 8800 GT OC by means of CPU | Percent |
|---|---|
| Geforce 8800 GT OC (512 MB) E2160@1.8 | 100.0 |
| Geforce 8800 GT OC (512 MB) E2160@2.41 | 116.5 |
| Geforce 8800 GT OC (512 MB) E6750@2.67 | 137.2 |
| Geforce 8800 GT OC (512 MB) Q6600@2.4 | 132.3 |
| Geforce 8800 GT OC (512 MB) Q6600@3.2 | 140.6 |
| Geforce 8800 GT OC (512 MB) X6800EE@2.94 | 138.2 |
A Geforce 8800 GT OC is as fast as an unclocked Geforce 8800 GTS 512. The streamlined graphics chip has only 112 stream processors instead of 128, which has an immediate effect on the maximum potential increase in performance. It is 3-5% lower than for the Geforce 8800 GTS 512 OC.
| Performance increase of 9600 GT OC 1024 by means of CPU | Percent |
|---|---|
| Geforce 9600 GT OC (1024 MB) E2160@1.8 | 100.0 |
| Geforce 9600 GT OC (1024 MB) E2160@2.41 | 116.3 |
| Geforce 9600 GT OC (1024 MB) E6750@2.67 | 133.3 |
| Geforce 9600 GT OC (1024 MB) Q6600@2.4 | 129.1 |
| Geforce 9600 GT OC (1024 MB) Q6600@3.2 | 136.5 |
| Geforce 9600 GT OC (1024 MB) X6800EE@2.94 | 134.8 |
Where the overclocked E2160 is able to obtain a 16% performance increase from the Geforce 9600 GT, the benefits sink to 3-4% for the more expensive CPUs, when the values are compared using the Geforce 8800 GT OC.
| Performance increase of 7950 GT by means of CPU | Percent |
|---|---|
| Geforce 7950 GT (512 MB) E2160@1.8 | 100.0 |
| Geforce 7950 GT (512 MB) E2160@2.41 | 107.3 |
| Geforce 7950 GT (512 MB) E6750@2.67 | 111.0 |
| Geforce 7950 GT (512 MB) Q6600@2.4 | 109.8 |
| Geforce 7950 GT (512 MB) Q6600@3.2 | 110.6 |
| Geforce 7950 GT (512 MB) X6800EE@2.94 | 111.2 |
A more powerful CPU increases the overall results of the Geforce 7950 GT by 11%. The overclocked Q6600 at 3.2 GHz loses points in this graphics card class to the E6750 at 2.67 GHz, or the X6800EE at 2.94 GHz.
| Performance increase of 6800 GT by means of CPU | Percent |
| Geforce 6800 GT (256 MB) E2160@1.8 | 100.0 |
| Geforce 6800 GT (256 MB) E2160@2.41 | 100.6 |
| Geforce 6800 GT (256 MB) E6750@2.67 | 102.1 |
| Geforce 6800 GT (256 MB) Q6600@2.4 | 96.8 |
| Geforce 6800 GT (256 MB) Q6600@3.2 | 98.1 |
| Geforce 6800 GT (256 MB) X6800EE@2.94 | 101.9 |
The Geforce 6800 GT barely profits from the better CPU; in fact, when used in conjunction with a quad core, it actually loses performance. These results arise because the Geforce 6 reaches its limits with maximum graphics quality and high test resolutions. With lower resolutions and graphics quality, the CPU is able to achieve more.
- Previous page Graphics Cards have More Potential
- Next page 3D Performance for the CPU
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- The Best Gaming Graphics cards for Your Money: March 2008
- Nvidia's GeForce 9600 GT Reviewed
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- The Best Gaming Graphics Cards for Your Money: February 2008
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The entry level cpu in a series have almost as much overclock potetial as a high end one, sometimes even more due to fsb clock.
The most bang for the buck is to had with a entry level cpu in a current series opverclocked, combined with the best grahics card in your budget (save money on cpu and put it towards gpu)
E.G. If someone has a 8600GT and a low spec CPU, it makes no sense to buy a new graphics card as this review coroborates the relation between GPU AND CPU.
Great stuff Tom's.
Also, Mackayde, the fact that you said 'coroborates' makes my point for me - this is ground already covered - we all know that mid range goes with mid range etc... for the best bang for the buck & price/performance ratio.
Err, of course you can make the bus speed faster by overclocking. What THG is suggesting is that the hit you get from using a cheaper CPU (i.e. less cache, lower bus speeds) can generally be dialled out by overclocking the CPU to death. i.e. run 3DMark on both, I bet you can easily get the same of better results from a lower prices CPU and many of the premium units.