GeForce GTX 650 vs Radeon HD 4890 1GB

Intro

Compare those specs to the Radeon HD 4890 1GB, which makes use of a 55 nm design. AMD has set the core speed at 1000 MHz. The GDDR5 RAM runs at a frequency of 975 MHz on this particular card. It features 800(160x5) SPUs as well as 40 Texture Address Units and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 650		64 Watts
Radeon HD 4890 1GB		190 Watts
	Difference: 126 Watts (197%)

Memory Bandwidth

In theory, the Radeon HD 4890 1GB should be much faster than the GeForce GTX 650 overall. (explain)

Radeon HD 4890 1GB		124800 MB/sec
GeForce GTX 650		80000 MB/sec
	Difference: 44800 (56%)

Texel Rate

The Radeon HD 4890 1GB is a small bit (more or less 18%) faster with regards to texture filtering than the GeForce GTX 650. (explain)

Radeon HD 4890 1GB		40000 Mtexels/sec
GeForce GTX 650		33856 Mtexels/sec
	Difference: 6144 (18%)

Pixel Rate

The GeForce GTX 650 will be a small bit (more or less 6%) better at FSAA than the Radeon HD 4890 1GB, and will be capable of handling higher resolutions while still performing well. (explain)

GeForce GTX 650		16928 Mpixels/sec
Radeon HD 4890 1GB		16000 Mpixels/sec
	Difference: 928 (6%)

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 maximum amount of information (counted in MB per second) that can be transported 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 RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the 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 in one second. This number is worked out by multiplying the total number of 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 in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly record to the local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.