Radeon HD 4890 1GB vs Radeon HD 7750

Intro

Compare those specifications to the Radeon HD 7750, which features a GPU core clock speed of 800 MHz, and 1024 MB of GDDR5 RAM running at 1125 MHz through a 128-bit bus. It also features 512 Stream Processors, 32 Texture Address Units, and 16 Raster Operation Units.

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 will be 73% quicker than the Radeon HD 7750 in general, due to its greater data rate. (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 much (approximately 56%) faster with regards to 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 should be quite a bit (approximately 25%) faster with regards to FSAA than the Radeon HD 7750, and also capable of handling higher resolutions while still performing well. (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: Bandwidth is the maximum amount of information (in units of MB per second) that can be transported across the external memory interface in a second. It is calculated by multiplying the bus width by the speed of its memory. If the card has DDR RAM, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

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

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