Radeon HD 3650 vs Radeon HD 7990

Intro

Compare all that to the Radeon HD 7990, which features a clock frequency of 950 MHz and a GDDR5 memory speed of 1500 MHz. It also uses a 384-bit memory bus, and makes use of a 28 nm design. It is comprised of 2048 SPUs, 128 Texture Address Units, and 32 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3650		78 Watts
Radeon HD 7990		375 Watts
	Difference: 297 Watts (381%)

Memory Bandwidth

In theory, the Radeon HD 7990 should be 2150% quicker than the Radeon HD 3650 overall, because of its greater data rate. (explain)

Radeon HD 7990		576000 MB/sec
Radeon HD 3650		25600 MB/sec
	Difference: 550400 (2150%)

Texel Rate

The Radeon HD 7990 is quite a bit (about 4093%) better at anisotropic filtering than the Radeon HD 3650. (explain)

Radeon HD 7990		243200 Mtexels/sec
Radeon HD 3650		5800 Mtexels/sec
	Difference: 237400 (4093%)

Pixel Rate

The Radeon HD 7990 will be a lot (about 1997%) faster with regards to full screen anti-aliasing than the Radeon HD 3650, and also will be able to handle higher resolutions without slowing down too much. (explain)

Radeon HD 7990		60800 Mpixels/sec
Radeon HD 3650		2900 Mpixels/sec
	Difference: 57900 (1997%)

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.

One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the maximum amount of information (measured in megabytes per second) that can be transported past the external memory interface within a second. The number is calculated by multiplying the bus width by its memory clock speed. If it uses DDR memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, 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 figure is calculated by multiplying the total number of texture units by the core speed of the chip. The higher the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly record to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the amount of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.