Compare any two graphics cards:
GeForce GTS 450 1GB vs Radeon HD 4850 512MB
IntroThe GeForce GTS 450 1GB has a GPU clock speed of 783 MHz, and the 1024 MB of GDDR5 RAM is set to run at 902 MHz through a 128-bit bus. It also is comprised of 192 SPUs, 32 TAUs, and 16 ROPs.
Compare those specs to the Radeon HD 4850 512MB, which uses a 55 nm design. AMD has clocked the core frequency at 625 MHz. The GDDR3 memory runs at a speed of 993 MHz on this particular model. It features 800(160x5) SPUs as well as 40 Texture Address Units and 16 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 4850 512MB should theoretically perform a little bit faster than the GeForce GTS 450 1GB overall. (explain)
Texel RateThe GeForce GTS 450 1GB will be just a bit (about 0%) more effective at AF than the Radeon HD 4850 512MB. (explain)
Pixel RateIf running with a high screen resolution is important to you, then the GeForce GTS 450 1GB is superior to the Radeon HD 4850 512MB, by far. (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 maximum amount of data (in units of MB per second) that can be transferred across the external memory interface in a second. The number is worked out by multiplying the interface width by its memory clock speed. If it uses DDR RAM, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This number is worked out by multiplying the total number of texture units by the core clock speed of the chip. The higher the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly write to its local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.