Radeon HD 7770 vs Radeon HD 7990

Intro

Compare all that to the Radeon HD 7990, which comes with core clock speeds of 950 MHz on the GPU, and 1500 MHz on the 3072 MB of GDDR5 RAM. It features 2048 SPUs along with 128 Texture Address Units and 32 ROPs.

Display Graphs

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Benchmarks

These are real-world performance benchmarks that were submitted by Hardware Compare users. The scores seen here are the average of all benchmarks submitted for each respective test and hardware.

3DMark Fire Strike Graphics Score

Radeon HD 7990		15520 points
Radeon HD 7770		3180 points
	Difference: 12340 (388%)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7770		80 Watts
Radeon HD 7990		375 Watts
	Difference: 295 Watts (369%)

Memory Bandwidth

The Radeon HD 7990 should in theory be quite a bit faster than the Radeon HD 7770 overall. (explain)

Radeon HD 7990		576000 MB/sec
Radeon HD 7770		72000 MB/sec
	Difference: 504000 (700%)

Texel Rate

The Radeon HD 7990 is quite a bit (about 508%) better at AF than the Radeon HD 7770. (explain)

Radeon HD 7990		243200 Mtexels/sec
Radeon HD 7770		40000 Mtexels/sec
	Difference: 203200 (508%)

Pixel Rate

If running with a high resolution is important to you, then the Radeon HD 7990 is a better choice, by a large margin. (explain)

Radeon HD 7990		60800 Mpixels/sec
Radeon HD 7770		16000 Mpixels/sec
	Difference: 44800 (280%)

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: Memory bandwidth is the maximum amount of data (in units of MB per second) that can be moved over the external memory interface within a second. It is worked out by multiplying the card's interface width by its memory clock speed. In the case of DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, 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 amount of texture map elements (texels) that are applied in one second. This number is worked out by multiplying the total texture units of the card by the core speed of the chip. The higher this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly write to the local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number of 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 is also dependant on quite a few 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.