GeForce 9800 GT 512MB vs Radeon HD 4870 512MB

Intro

Compare those specs to the Radeon HD 4870 512MB, which has a core clock speed of 750 MHz and a GDDR5 memory frequency of 900 MHz. It also makes use of a 256-bit memory bus, and uses a 55 nm design. It is comprised of 800(160x5) SPUs, 40 TAUs, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 9800 GT 512MB		105 Watts
Radeon HD 4870 512MB		150 Watts
	Difference: 45 Watts (43%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 4870 512MB will be 100% quicker than the GeForce 9800 GT 512MB overall, due to its higher data rate. (explain)

Radeon HD 4870 512MB		115200 MB/sec
GeForce 9800 GT 512MB		57600 MB/sec
	Difference: 57600 (100%)

Texel Rate

The GeForce 9800 GT 512MB will be a bit (about 12%) faster with regards to texture filtering than the Radeon HD 4870 512MB. (explain)

GeForce 9800 GT 512MB		33600 Mtexels/sec
Radeon HD 4870 512MB		30000 Mtexels/sec
	Difference: 3600 (12%)

Pixel Rate

The Radeon HD 4870 512MB is a lot (approximately 25%) faster with regards to AA than the GeForce 9800 GT 512MB, and will be able to handle higher screen resolutions without slowing down too much. (explain)

Radeon HD 4870 512MB		12000 Mpixels/sec
GeForce 9800 GT 512MB		9600 Mpixels/sec
	Difference: 2400 (25%)

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.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the max amount of information (in units of MB per second) that can be transferred across the external memory interface in a second. It is worked out by multiplying the card's bus width by the speed of its memory. In the case of DDR memory, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the bandwidth is, the faster 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 is worked out by multiplying the total amount of texture units of the card by the core speed of the chip. The higher this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the maximum number of pixels the graphics 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 number of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.