Radeon HD 3870 512MB vs Radeon HD 4770

Intro

Compare those specs to the Radeon HD 4770, which has GPU clock speed of 750 MHz, and 512 MB of GDDR5 RAM set to run at 800 MHz through a 128-bit bus. It also is made up of 640(128x5) Stream Processors, 32 TAUs, and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4770		80 Watts
Radeon HD 3870 512MB		106 Watts
	Difference: 26 Watts (33%)

Memory Bandwidth

In theory, the Radeon HD 3870 512MB should be just a bit faster than the Radeon HD 4770 overall. (explain)

Radeon HD 3870 512MB		57600 MB/sec
Radeon HD 4770		51200 MB/sec
	Difference: 6400 (13%)

Texel Rate

The Radeon HD 4770 should be quite a bit (about 94%) more effective at AF than the Radeon HD 3870 512MB. (explain)

Radeon HD 4770		24000 Mtexels/sec
Radeon HD 3870 512MB		12400 Mtexels/sec
	Difference: 11600 (94%)

Pixel Rate

The Radeon HD 3870 512MB is just a bit (approximately 3%) faster with regards to AA than the Radeon HD 4770, and also should be able to handle higher resolutions better. (explain)

Radeon HD 3870 512MB		12400 Mpixels/sec
Radeon HD 4770		12000 Mpixels/sec
	Difference: 400 (3%)

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. The number is calculated by multiplying the bus width by its memory clock speed. If the card has DDR RAM, it should be multiplied by 2 again. If it uses 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 higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied in one second. This is calculated by multiplying the total 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 handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly write to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the max fill rate.