Compare any two graphics cards:
GeForce 9800 GT 1GB vs GeForce GT 340
IntroThe GeForce 9800 GT 1GB features a GPU core speed of 600 MHz, and the 1024 MB of GDDR3 memory runs at 900 MHz through a 256-bit bus. It also features 112 Stream Processors, 56 Texture Address Units, and 16 ROPs.
Compare all of that to the GeForce GT 340, which has a clock speed of 550 MHz and a GDDR5 memory frequency of 850 MHz. It also uses a 128-bit bus, and makes use of a 40 nm design. It is comprised of 96 SPUs, 32 TAUs, and 8 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the GeForce 9800 GT 1GB should theoretically be just a bit better than the GeForce GT 340 in general. (explain)
Texel RateThe GeForce 9800 GT 1GB should be a lot (more or less 91%) better at texture filtering than the GeForce GT 340. (explain)
Pixel RateThe GeForce 9800 GT 1GB should be much (approximately 118%) faster with regards to full screen anti-aliasing than the GeForce GT 340, and also should be capable of handling higher resolutions without losing too much performance. (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.
Memory Bandwidth: Bandwidth is the max amount of information (in units of megabytes per second) that can be moved past the external memory interface within a second. The number is worked out by multiplying the card's interface width by the speed of its memory. If it uses DDR memory, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed per second. This figure is worked out by multiplying the total texture units of the card by the core speed of the chip. The better the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.