Radeon HD 4890 1GB vs Radeon HD 7750

Intro

Compare those specifications to the Radeon HD 7750, which comes with a GPU core clock speed of 800 MHz, and 1024 MB of GDDR5 RAM set to run at 1125 MHz through a 128-bit bus. It also is made up of 512 Stream Processors, 32 TAUs, and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7750		55 Watts
Radeon HD 4890 1GB		190 Watts
	Difference: 135 Watts (245%)

Memory Bandwidth

Theoretically, the Radeon HD 4890 1GB should perform quite a bit faster than the Radeon HD 7750 in general. (explain)

Radeon HD 4890 1GB		124800 MB/sec
Radeon HD 7750		72000 MB/sec
	Difference: 52800 (73%)

Texel Rate

The Radeon HD 4890 1GB is quite a bit (approximately 56%) more effective at anisotropic filtering than the Radeon HD 7750. (explain)

Radeon HD 4890 1GB		40000 Mtexels/sec
Radeon HD 7750		25600 Mtexels/sec
	Difference: 14400 (56%)

Pixel Rate

The Radeon HD 4890 1GB will be a lot (more or less 25%) more effective at FSAA than the Radeon HD 7750, and also will be capable of handling higher screen resolutions more effectively. (explain)

Radeon HD 4890 1GB		16000 Mpixels/sec
Radeon HD 7750		12800 Mpixels/sec
	Difference: 3200 (25%)

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 (counted in megabytes per second) that can be transferred over the external memory interface within a second. The number is worked out by multiplying the card's interface width by its memory speed. If the card has DDR type RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the faster 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 number of texture map elements (texels) that can be processed in one second. This figure is worked out by multiplying the total amount of texture units of the card by the core clock speed of the chip. The better the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly record to the 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 clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.