Compare any two graphics cards:
Radeon HD 4670 1GB vs Radeon HD 7770
IntroThe Radeon HD 4670 1GB has core speeds of 750 MHz on the GPU, and 1100 MHz on the 1024 MB of GDDR4/GDDR3/DDR3/DDR2 RAM. It features 320(64x5) SPUs along with 32 TAUs and 8 ROPs.
Compare all of that to the Radeon HD 7770, which features core clock speeds of 1000 MHz on the GPU, and 1125 MHz on the 1024 MB of GDDR5 memory. It features 640 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)
In theory, the Radeon HD 7770 should be 105% quicker than the Radeon HD 4670 1GB in general, due to its higher bandwidth. (explain)
Texel RateThe Radeon HD 7770 will be a lot (approximately 67%) faster with regards to anisotropic filtering than the Radeon HD 4670 1GB. (explain)
Pixel RateIf running with high levels of AA is important to you, then the Radeon HD 7770 is superior to the Radeon HD 4670 1GB, by a large margin. (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 information (in units of MB per second) that can be transferred across the external memory interface within a second. It's calculated by multiplying the card's bus width by its memory clock speed. If it uses DDR type RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed in one second. This number is worked out by multiplying the total texture units by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at 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 can possibly record to its local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate is also dependant on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the max fill rate.