GeForce GT 450 (OEM) vs Radeon HD 7990

Intro

Compare those specs to the Radeon HD 7990, which features GPU clock speed of 950 MHz, and 3072 MB of GDDR5 RAM running at 1500 MHz through a 384-bit bus. It also is comprised of 2048 SPUs, 128 TAUs, and 32 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 450 (OEM)		106 Watts
Radeon HD 7990		375 Watts
	Difference: 269 Watts (254%)

Memory Bandwidth

In theory, the Radeon HD 7990 should be 500% faster than the GeForce GT 450 (OEM) overall, due to its greater bandwidth. (explain)

Radeon HD 7990		576000 MB/sec
GeForce GT 450 (OEM)		96000 MB/sec
	Difference: 480000 (500%)

Texel Rate

The Radeon HD 7990 will be quite a bit (approximately 1183%) more effective at texture filtering than the GeForce GT 450 (OEM). (explain)

Radeon HD 7990		243200 Mtexels/sec
GeForce GT 450 (OEM)		18960 Mtexels/sec
	Difference: 224240 (1183%)

Pixel Rate

The Radeon HD 7990 will be quite a bit (more or less 221%) more effective at anti-aliasing than the GeForce GT 450 (OEM), and also should be able to handle higher resolutions more effectively. (explain)

Radeon HD 7990		60800 Mpixels/sec
GeForce GT 450 (OEM)		18960 Mpixels/sec
	Difference: 41840 (221%)

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.

One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the largest amount of information (in units of megabytes per second) that can be moved over the external memory interface within a second. It's worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR RAM, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. 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 are applied in one second. This is worked out by multiplying the total amount of texture units by the core 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 a second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly write to its local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). 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 get to the max fill rate.