Compare any two graphics cards:
GeForce GTX 650 vs Radeon HD 4890 2GB
IntroThe GeForce GTX 650 has a GPU core speed of 1058 MHz, and the 2048 MB of GDDR5 RAM is set to run at 1250 MHz through a 128-bit bus. It also features 384 SPUs, 32 TAUs, and 16 Raster Operation Units.
Compare those specs to the Radeon HD 4890 2GB, which makes use of a 55 nm design. AMD has clocked the core speed at 1000 MHz. The GDDR5 RAM runs at a frequency of 975 MHz on this specific model. It features 800(160x5) SPUs along with 40 Texture Address Units and 16 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 4890 2GB should be 56% quicker than the GeForce GTX 650 in general, due to its higher data rate. (explain)
Texel RateThe Radeon HD 4890 2GB will be a small bit (about 18%) more effective at anisotropic filtering than the GeForce GTX 650. (explain)
Pixel RateThe GeForce GTX 650 will be a little bit (about 6%) more effective at anti-aliasing than the Radeon HD 4890 2GB, and will be able to handle higher resolutions while still performing well. (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: Memory bandwidth is the largest amount of data (counted in megabytes per second) that can be transferred over the external memory interface in a second. It's worked out by multiplying the bus width by its memory clock speed. If it uses DDR memory, the result 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, HDR and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed per second. This number is calculated by multiplying the total number of texture units by the core clock speed of the chip. The better the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the most pixels the video card could possibly record to the local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.