Radeon HD 6450 (OEM) 1GB vs Radeon HD 7990

Intro

Compare that to the Radeon HD 7990, which comes with a clock frequency of 950 MHz and a GDDR5 memory speed of 1500 MHz. It also features a 384-bit bus, and uses a 28 nm design. It is made up of 2048 SPUs, 128 Texture Address Units, and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6450 (OEM) 1GB		31 Watts
Radeon HD 7990		375 Watts
	Difference: 344 Watts (1110%)

Memory Bandwidth

In theory, the Radeon HD 7990 will be 1900% quicker than the Radeon HD 6450 (OEM) 1GB in general, due to its higher data rate. (explain)

Radeon HD 7990		576000 MB/sec
Radeon HD 6450 (OEM) 1GB		28800 MB/sec
	Difference: 547200 (1900%)

Texel Rate

The Radeon HD 7990 is quite a bit (approximately 3953%) faster with regards to texture filtering than the Radeon HD 6450 (OEM) 1GB. (explain)

Radeon HD 7990		243200 Mtexels/sec
Radeon HD 6450 (OEM) 1GB		6000 Mtexels/sec
	Difference: 237200 (3953%)

Pixel Rate

The Radeon HD 7990 should be much (more or less 1927%) more effective at FSAA than the Radeon HD 6450 (OEM) 1GB, and will be capable of handling higher screen resolutions better. (explain)

Radeon HD 7990		60800 Mpixels/sec
Radeon HD 6450 (OEM) 1GB		3000 Mpixels/sec
	Difference: 57800 (1927%)

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 max amount of information (in units of MB per second) that can be transferred across the external memory interface in a second. It's calculated by multiplying the bus width by the speed of its memory. In the case of DDR type memory, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied per second. This figure is calculated by multiplying the total amount of texture units by the core speed of the chip. The better the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.

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