GeForce 9800 GX2 vs GeForce GT 420

Intro

Compare those specs to the GeForce GT 420, which comes with core speeds of 700 MHz on the GPU, and 900 MHz on the 2048 MB of GDDR3 RAM. It features 48 SPUs along with 8 TAUs and 4 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 420		50 Watts
GeForce 9800 GX2		197 Watts
	Difference: 147 Watts (294%)

Memory Bandwidth

As far as performance goes, the GeForce 9800 GX2 should in theory be a lot better than the GeForce GT 420 in general. (explain)

GeForce 9800 GX2		128000 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 99200 (344%)

Texel Rate

The GeForce 9800 GX2 is a lot (about 1271%) better at AF than the GeForce GT 420. (explain)

GeForce 9800 GX2		76800 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 71200 (1271%)

Pixel Rate

If using a high resolution is important to you, then the GeForce 9800 GX2 is superior to the GeForce GT 420, by far. (explain)

GeForce 9800 GX2		19200 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 16400 (586%)

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 largest amount of data (measured in MB per second) that can be moved past the external memory interface in a second. The number is calculated by multiplying the card's interface width by its memory speed. If it uses DDR memory, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly record to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of ROPs by the the core 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 is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.