Radeon HD 3870 1GB vs Radeon HD 6770

Intro

Compare those specs to the Radeon HD 6770, which has GPU clock speed of 900 MHz, and 512 MB of GDDR5 memory running at 1050 MHz through a 128-bit bus. It also features 800 Stream Processors, 40 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3870 1GB		106 Watts
Radeon HD 6770		108 Watts
	Difference: 2 Watts (2%)

Memory Bandwidth

Performance-wise, the Radeon HD 3870 1GB should theoretically be a small bit better than the Radeon HD 6770 overall. (explain)

Radeon HD 3870 1GB		72000 MB/sec
Radeon HD 6770		67200 MB/sec
	Difference: 4800 (7%)

Texel Rate

The Radeon HD 6770 will be quite a bit (more or less 190%) faster with regards to AF than the Radeon HD 3870 1GB. (explain)

Radeon HD 6770		36000 Mtexels/sec
Radeon HD 3870 1GB		12400 Mtexels/sec
	Difference: 23600 (190%)

Pixel Rate

If running with a high screen resolution is important to you, then the Radeon HD 6770 is superior to the Radeon HD 3870 1GB, but it probably won't make a huge difference. (explain)

Radeon HD 6770		14400 Mpixels/sec
Radeon HD 3870 1GB		12400 Mpixels/sec
	Difference: 2000 (16%)

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 transported past the external memory interface in one second. It's worked out by multiplying the bus width by the speed of its memory. In the case of DDR RAM, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied per second. This figure is calculated by multiplying the total amount of texture units by the core clock speed of the chip. The higher this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip could possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.