Budget Video Card Comparison - November 2000

The NVIDIA GeForce2 MX

Perhaps the most well known of the bunch, and in many incarnations the cheapest, NVIDIA's GeForce2 MX chip powers quite a variety of budget video cards that are on the market today. Since NVIDIA only makes the chips and relies on third party manufacturers to make the cards, we have seen quite a few GeForce2 MX based budget cards out there. Before we go into the two different types of GeForce2 MX cards there are out there, let's take a look at the core itself.

The GeForce2 MX core is very similar to its more powerful GeForce2 GTS brother, however there are some key differences that designate the MX as a budget chip. The MX contains the same advanced T&L engine found on the more expensive GTS and Ultra chips. This engine is NVIDIA's second generation T&L processor and this time gains the ability to perform not only transform and lighting calculations but also clipping calculations. Because of its lower clock speed, the engine boasts the ability to process 20 million triangles per second versus 25 million on the GeForce2 GTS. In addition, the MX is produced on a 0.18 micron process, making it cooler running and less power hungry than the 0.25 micron VSA-100 chip used in the Voodoo4 4500.

It is here, however, that the similarities between the GeForce2 GTS core and the GeForce2 MX core end. Perhaps one of the most disappointing cutbacks that the MX has is the fact that two of the four rendering pipelines present on the GTS are lost. The GeForce2 MX contains a total of two rendering pipelines, each capable of processing two texels per clock. This produces a total of two pixels per clock when in a dual textured game, exactly half of the GeForce2 GTS' four. By cutting out two of the memory pipelines on the GeForce2 MX, NVIDIA is able to reduce die size as well a chip complexity, thus reducing overall cost.

The second most disappointing cutback present on the GeForce2 MX is its clock speed. In order to increase yields and thus decrease production costs, NVIDIA clocks all GeForce2 MX chips at 175MHz, 25MHz shy of its higher performing brother. This does two things for card producers. First off, it means that no fan or heatsink is required for proper operation. Since heatsinks and fans do not come cheap, not requiring any form of cooling keeps the cost of the GeForce2 MX cards down. Although we do see some manufacturers including heatsinks and even fans, they are not necessary for normal operation. Secondly, lowering the clock speed ensures the MX's place as a budget core, meaning that it is kept a safe distance from potential GTS buyers. The worst situation for NVIDIA is to have two products competing against each other and by clocking the GeForce2 MX at 175MHz core, it can be assured that the MX's performance falls well below that of the GTS core. Thankfully, not all of the news surrounding the lower clock speed is bad. Since the MX core is so similar to the GTS core, one can be almost certain that with some cooling every MX will reach an overclocked speed of around 200 MHz with a bit of tweaking.

Although the value side of the MX may shine through when examining the list of features lost, one attractive feature is gained: TwinView. TwinView is NVIDIA's answer to Matrox's DualHead technology that allows for the use of a second monitor on a single video card. This feature is targeted more at the workstation market, but is also quite nifty for users out there with a second monitor lying around. Most of the truly "budget" GeForce2 MX cards will not have a second VGA or DVI connector, for a bit more one can get a card that can take advantage of this feature.

A second feature added to the MX core is what NVIDIA calls "digital vibrance control." According to NVIDIA, this technology allows the user to "manage the digital bitstream between the graphics pipeline and the display system," thus resulting in more accurate color management. In our testing, we found that digital vibrance control is nothing more than glorified gamma control that is packaged with the GeForce2 MX's drivers.

When both the decreased rendering pipelines and decreased clock speed are taken into account, we can see that the GeForce2 MX can output 700 million texels per second, well below the 1600 million texels per second the GeForce2 GTS is capable of doing. Then again, some of what is lost in speed is made up for in features not found on any other NVIDIA card.