Compare any two graphics cards:
GeForce GTX 260 vs Radeon HD 4890 1GB
IntroThe GeForce GTX 260 features a core clock frequency of 576 MHz and a GDDR3 memory frequency of 999 MHz. It also uses a 448-bit bus, and uses a 65 nm design. It is made up of 192 SPUs, 64 TAUs, and 28 ROPs.
Compare all that to the Radeon HD 4890 1GB, which features GPU clock speed of 1000 MHz, and 1024 MB of GDDR5 RAM set to run at 975 MHz through a 256-bit bus. It also features 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the Radeon HD 4890 1GB should theoretically be just a bit better than the GeForce GTX 260 overall. (explain)
Texel RateThe Radeon HD 4890 1GB should be just a bit (about 9%) more effective at texture filtering than the GeForce GTX 260. (explain)
Pixel RateThe GeForce GTX 260 will be a little bit (about 1%) more effective at FSAA than the Radeon HD 4890 1GB, and will be able to handle higher resolutions more effectively. (explain)
Please note that the above 'benchmarks' are all just theoretical - the results were calculated based on the card's specifications, and real-world performance may (and probably will) vary at least a bit.
Please note that the price comparisons are based on search keywords - sometimes it might show cards with very similar names that are not exactly the same as the one chosen in the comparison. We do try to filter out the wrong results as best we can, though.
Memory Bandwidth: Bandwidth is the max amount of information (in units of megabytes per second) that can be transported over the external memory interface in one second. It's calculated by multiplying the bus width by its memory clock speed. If the card has DDR memory, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed per second. This figure is worked out by multiplying the total amount of texture units of the card by the core clock speed of the chip. The better this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly write to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.