Radeon HD 4890 1GB vs Radeon HD 7750

Intro

Compare all that to the Radeon HD 7750, which uses a 28 nm design. AMD has clocked the core frequency at 800 MHz. The GDDR5 memory is set to run at a frequency of 1125 MHz on this specific model. It features 512 SPUs along with 32 Texture Address Units and 16 ROPs.

Display Graphs

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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

In theory, the Radeon HD 4890 1GB is 73% quicker than the Radeon HD 7750 overall, due to its greater bandwidth. (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 (about 56%) better at AF 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 should be quite a bit (approximately 25%) faster with regards to FSAA than the Radeon HD 7750, and also able to handle 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 max amount of information (in units of megabytes per second) that can be moved across the external memory interface in a second. It is calculated by multiplying the bus width by its memory speed. In the case of DDR type memory, the result should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high 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 by the core clock speed of the chip. The higher this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.