Compare any two graphics cards:
Radeon HD 4650 512MB vs Radeon HD 6450 (OEM) 1GB
IntroThe Radeon HD 4650 512MB makes use of a 55 nm design. AMD has clocked the core speed at 600 MHz. The DDR2 memory runs at a speed of 500 MHz on this model. It features 320(64x5) SPUs as well as 32 Texture Address Units and 8 Rasterization Operator Units.
Compare that to the Radeon HD 6450 (OEM) 1GB, which makes use of a 40 nm design. AMD has clocked the core frequency at 750 MHz. The GDDR5 memory works at a frequency of 900 MHz on this card. It features 160 SPUs as well as 8 TAUs and 4 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the Radeon HD 6450 (OEM) 1GB should theoretically be quite a bit superior to the Radeon HD 4650 512MB overall. (explain)
Texel RateThe Radeon HD 4650 512MB is quite a bit (approximately 220%) more effective at anisotropic filtering than the Radeon HD 6450 (OEM) 1GB. (explain)
Pixel RateIf using high levels of AA is important to you, then the Radeon HD 4650 512MB is the winner, 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: Bandwidth is the max amount of information (in units of MB per second) that can be moved across the external memory interface in one second. The number is calculated by multiplying the card's interface width by the speed of its memory. If the card has DDR RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed in one second. This number is calculated by multiplying the total amount of texture units by the core speed of the chip. The higher the texel rate, the better the card will be at 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 the video 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 amount of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.