Radeon HD 4850 1GB vs Radeon HD 7770

Intro

Compare that to the Radeon HD 7770, which uses a 28 nm design. AMD has set the core speed at 1000 MHz. The GDDR5 memory runs at a speed of 1125 MHz on this particular card. It features 640 SPUs along with 40 TAUs and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7770		80 Watts
Radeon HD 4850 1GB		110 Watts
	Difference: 30 Watts (38%)

Memory Bandwidth

In theory, the Radeon HD 7770 should be 13% quicker than the Radeon HD 4850 1GB overall, because of its greater data rate. (explain)

Radeon HD 7770		72000 MB/sec
Radeon HD 4850 1GB		63552 MB/sec
	Difference: 8448 (13%)

Texel Rate

The Radeon HD 7770 should be much (about 60%) more effective at AF than the Radeon HD 4850 1GB. (explain)

Radeon HD 7770		40000 Mtexels/sec
Radeon HD 4850 1GB		25000 Mtexels/sec
	Difference: 15000 (60%)

Pixel Rate

The Radeon HD 7770 should be a lot (about 60%) faster with regards to anti-aliasing than the Radeon HD 4850 1GB, and also able to handle higher screen resolutions more effectively. (explain)

Radeon HD 7770		16000 Mpixels/sec
Radeon HD 4850 1GB		10000 Mpixels/sec
	Difference: 6000 (60%)

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 (measured in MB per second) that can be transported past the external memory interface in a second. It is worked out by multiplying the card's interface width by its memory clock speed. In the case of DDR memory, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This number is calculated by multiplying the total texture units 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 number of pixels the graphics card can possibly record to the local memory in a second - measured in millions of pixels per second. The figure is worked out 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 drawing the pixels (image) on the screen. The actual pixel output rate also depends on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.