Radeon HD 4850 512MB vs Radeon HD 7790

Intro

Compare all that to the Radeon HD 7790, which uses a 28 nm design. AMD has set the core frequency at 1000 MHz. The GDDR5 RAM works at a frequency of 1500 MHz on this model. It features 896 SPUs along with 56 TAUs and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7790		85 Watts
Radeon HD 4850 512MB		110 Watts
	Difference: 25 Watts (29%)

Memory Bandwidth

Theoretically, the Radeon HD 7790 should be quite a bit faster than the Radeon HD 4850 512MB in general. (explain)

Radeon HD 7790		96000 MB/sec
Radeon HD 4850 512MB		63552 MB/sec
	Difference: 32448 (51%)

Texel Rate

The Radeon HD 7790 should be much (more or less 124%) better at anisotropic filtering than the Radeon HD 4850 512MB. (explain)

Radeon HD 7790		56000 Mtexels/sec
Radeon HD 4850 512MB		25000 Mtexels/sec
	Difference: 31000 (124%)

Pixel Rate

The Radeon HD 7790 should be quite a bit (more or less 60%) faster with regards to FSAA than the Radeon HD 4850 512MB, and also will be capable of handling higher screen resolutions while still performing well. (explain)

Radeon HD 7790		16000 Mpixels/sec
Radeon HD 4850 512MB		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: Memory bandwidth is the largest amount of information (measured in megabytes per second) that can be transported across the external memory interface in one second. It is worked out by multiplying the bus width by its memory clock speed. If the card has DDR memory, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the most pixels the graphics card could possibly write to the local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the number of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.