Radeon HD 4890 1GB vs Radeon HD 5770

Intro

Compare those specs to the Radeon HD 5770, which uses a 40 nm design. AMD has clocked the core speed at 850 MHz. The GDDR5 memory is set to run at a speed of 1200 MHz on this particular card. It features 800(160x5) SPUs as well as 40 TAUs and 16 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 5770		108 Watts
Radeon HD 4890 1GB		190 Watts
	Difference: 82 Watts (76%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 4890 1GB should be quite a bit faster than the Radeon HD 5770 in general. (explain)

Radeon HD 4890 1GB		124800 MB/sec
Radeon HD 5770		76800 MB/sec
	Difference: 48000 (63%)

Texel Rate

The Radeon HD 4890 1GB will be a little bit (about 18%) more effective at texture filtering than the Radeon HD 5770. (explain)

Radeon HD 4890 1GB		40000 Mtexels/sec
Radeon HD 5770		34000 Mtexels/sec
	Difference: 6000 (18%)

Pixel Rate

If running with a high resolution is important to you, then the Radeon HD 4890 1GB is the winner, but not by far. (explain)

Radeon HD 4890 1GB		16000 Mpixels/sec
Radeon HD 5770		13600 Mpixels/sec
	Difference: 2400 (18%)

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: Memory bandwidth is the largest amount of information (in units of MB per second) that can be transported past the external memory interface within a second. It's worked out by multiplying the interface width by its memory clock speed. If the card has DDR RAM, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the 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 number is calculated by multiplying the total texture units by the core clock speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly write to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the max fill rate.