Tom's Hardware > All Reviews > Components > Graphics Cards > Comparison: Factory-Overclocked Versus Reference Graphics

Comparison: Factory-Overclocked Versus Reference Graphics

09:50 - Sunday 25 July 2010 by Tino Kreiss

1. GPU Overclocking Is Half Of The Story
2. Graphics Cards And Configurations Compared
3. Differences: Reference Versus Aftermarket
4. 2D Temperature, Noise, Power Consumption
5. 3D Temperature, Noise, Power Consumption
6. Overclocking
7. Cross-Check
8. Benchmarks: Alien Vs. Predator
9. Benchmarks: Avatar

10. Benchmarks: Battlefield Bad Company 2
11. Benchmarks: Dragon Age: Origins
12. Benchmarks: Left 4 Dead 2
13. Benchmarks: Mass Effect 2
14. Benchmarks: Supreme Commander 2
15. Benchmarks: 3DMark06
16. Overall Performance
17. Power, Noise, And Temperature
18. 3D Performance, Ordered By Resolution And AA
19. Conclusion

In order to their products apart, third-party vendors take reference GPUs from AMD and Nvidia, and then make their own tweaks to layout, cooling, and performance. We're comparing a tuned-up card from MSI to AMD's reference Radeon HD 5870 to measure value.

When it comes to setting the clock rates on non-reference graphics cards, third-party vendors take different routes. Some overclocked cards employ higher GPU clocks, but they don’t always alter memory data rates. Typically, the GPU speed can be modified afterward through software tools (incidentally, most reference cards can also be tweaked fairly easily). These tools typically allow users to also adjust memory clock speeds, which is a critical warranty item. Experience shows that memory is more sensitive to overclocking. In addition, overclocking often alters 2D clocks as well, causing your card to use more power and requiring more cooling when it sitting there idle.

If you manually overclock a graphics card, you cannot know without some testing if the target settings remain effective, or if throttling in 2D mode is still possible. We've seen plenty of instances where an overclocked card ends up running at its maximum clocks, even on the Windows desktop. That defeats the purpose of throttling entirely, generating a lot of unnecessary heat your cooling subsystem is forced to deal with.

Factory-overclocked cards, however, correctly implement modified speed settings, meaning that they run the tweaked clock speeds in 3D mode and still throttle clock speeds and power consumption in 2D mode, making them more efficient, at least, without any aftermarket tweaking needed.

In this article, we’ll compare a reference ATI Radeon HD 5870 card and the factory-overclocked MSI R5870 Lightning TwinFrozr II, analyzing real-world differences between the two. We'll also run the reference card at overclocked settings as well, because we wanted to see if the pricier aftermarket solution can deliver more value than a reference board tuned to run faster.