Radeon HD 3870 1GB vs Radeon HD 5770

Intro

Compare all of that to the Radeon HD 5770, which features a core clock speed of 850 MHz and a GDDR5 memory speed of 1200 MHz. It also makes use of a 128-bit memory bus, and makes use of a 40 nm design. It features 800(160x5) SPUs, 40 TAUs, and 16 ROPs.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3870 1GB		106 Watts
Radeon HD 5770		108 Watts
	Difference: 2 Watts (2%)

Memory Bandwidth

In theory, the Radeon HD 5770 should be a little bit faster than the Radeon HD 3870 1GB in general. (explain)

Radeon HD 5770		76800 MB/sec
Radeon HD 3870 1GB		72000 MB/sec
	Difference: 4800 (7%)

Texel Rate

The Radeon HD 5770 will be quite a bit (about 174%) faster with regards to anisotropic filtering than the Radeon HD 3870 1GB. (explain)

Radeon HD 5770		34000 Mtexels/sec
Radeon HD 3870 1GB		12400 Mtexels/sec
	Difference: 21600 (174%)

Pixel Rate

The Radeon HD 5770 is a bit (approximately 10%) faster with regards to full screen anti-aliasing than the Radeon HD 3870 1GB, and should be able to handle higher resolutions without slowing down too much. (explain)

Radeon HD 5770		13600 Mpixels/sec
Radeon HD 3870 1GB		12400 Mpixels/sec
	Difference: 1200 (10%)

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 maximum amount of data (measured in megabytes per second) that can be transported past the external memory interface within a second. It's worked out by multiplying the card's interface width by the speed of its memory. If it uses DDR type RAM, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the better 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 texture map elements (texels) that are applied per second. This number is worked out by multiplying the total amount of 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 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 card can possibly write to the local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of Render Output Units 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 is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.