The Sapphire Radeon HD 4650 OC costs slightly less than the Radeon HD 4670, which works out to be about 15% less for this budget graphics card, but when using OverDrive we had no problems beating the HD 4670 when it came to the frame-rate performance in all of the Linux OpenGL tests.
The factory-overclocked HD 4650 was generally within a few frames per second of the HD 4670, but once squeezing a few more megahertz out of the RV730PRO core and video memory it had no problems running up against the RV730XT. In the 2D GtkPerf testing, the performance was roughly the same between all of the ATI graphics cards tested.
Sapphire's Radeon HD 4650 OC does cost about $20 USD more than the Radeon HD 4550, but in the OpenGL tests it was twice as fast (and in some cases, even more) as the RV710 GPU.
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