Radeon HD 4870 512MB vs Radeon HD 5770

Intro

Compare all of that to the Radeon HD 5770, which features GPU core speed of 850 MHz, and 1024 MB of GDDR5 memory running at 1200 MHz through a 128-bit bus. It also features 800(160x5) Stream Processors, 40 TAUs, and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 5770		108 Watts
Radeon HD 4870 512MB		150 Watts
	Difference: 42 Watts (39%)

Memory Bandwidth

As far as performance goes, the Radeon HD 4870 512MB should in theory be a lot superior to the Radeon HD 5770 overall. (explain)

Radeon HD 4870 512MB		115200 MB/sec
Radeon HD 5770		76800 MB/sec
	Difference: 38400 (50%)

Texel Rate

The Radeon HD 5770 will be a small bit (more or less 13%) better at texture filtering than the Radeon HD 4870 512MB. (explain)

Radeon HD 5770		34000 Mtexels/sec
Radeon HD 4870 512MB		30000 Mtexels/sec
	Difference: 4000 (13%)

Pixel Rate

The Radeon HD 5770 is a small bit (approximately 13%) better at AA than the Radeon HD 4870 512MB, and will be able to handle higher screen resolutions more effectively. (explain)

Radeon HD 5770		13600 Mpixels/sec
Radeon HD 4870 512MB		12000 Mpixels/sec
	Difference: 1600 (13%)

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 data (in units of megabytes per second) that can be transported over the external memory interface in a second. It is calculated by multiplying the interface width by its memory clock speed. If the card has DDR memory, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the card's 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 are processed in one second. This number is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly record to its local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the max fill rate.