Graphic cards

Introduction:

The graphic system is a tight coupling between the graphic card and the graphic monitor. This fact is so true that these devices should always be bought together. Graphic monitors supported performances are those allowed by its internal circuitry and the included cathode ray tube as well as the supported performances of the graphiccard driving it.

A good monitor is by definition a monitor with sufficient displaying surface to allow a comfortable readability without effort from the user, a close matching to the real natural colors, enough brightness and contrast to give realistic details even when the images are not ideal, no visible flicking so it wont tear your eyes even after a long period of use, a choice of color resolution large enough to allow an interesting variety of color resolutions and a screen dot pitch small enough so the images details will look close to photo realistic quality. In numbers, this would mean at least a 15 inches monitor capable to support a refresh rate of at least 72hz to 75hz at a screen resolution of 1024 X 768 with a dot pitch of .28 which actually is the case of most of the middle grade monitors. For better performances a 17 inches monitor is more flexible but in this case you should choose one that would support screen resolution of 1600 X 1200 at a refresh rate of at least 85hz at the highest screen resolution with a dot pitch of .25 so the images wont look grainy while no flicker will be perceptible.

A dot is the smallest possible portion of a screen monitor and its size is varying according to the picture tube quality while a pixel is a determined area covering a portion on the monitor screen which size is determined by the application is use. In other word a pixel can use more than one screen dot but can never be smaller than one screen dot. However, on a high definition monitor a pixel can be so small on the monitor display that if someone would use a black background screen where only a single white pixel would be displayed it could be very difficult to locate it by most of the people.

To summarize all this we could say that a graphic monitor quality can be determined by the following criteria:

* A small dot pitch
* A high screen resolution
* A high refresh rate
* A large diplay surface

The relative importance of these criteria are very much depending of your own personal needs and budget of course. The smaller the dot pitch or the largest the display surface of a monitor the more expensive the monitor usually is so you may have to sacrifice some display surface to get a monitor size that fits your budget. A good rule is to get the smallest possible screen dot pitch that you can afford for the monitor size you intend to buy. In any case you should never change an existing monitor for a larger one using the same dot pitch if you don't want to lose any image definition because the large the display surface is the lower its definition will be if its dot pitch is not reduced accordingly. For instance, on very large display you will have to establish a good distance between you and the monitor if you don't want to see the granularity effect. While this effect is more perceptible on TV screen it can also be observed on computer graphic monitor display using very large screen.

Just as a reminder I would like to summarize the different color depth and their corresponding names so you could use it in the suite of this page where these names will be widely referred to:

* 8-bits = 256 color named the VGA mode
* 16-bits = 65,536 colors named the high color mode or SVGA
* 24-bits = 16.7m colors named True color mode
* 32-bits = 16.7m colors named True color mode



Graphic cards Basic Hardware informations:

A graphic card is a very complex device. As a matter of fact there are so many components on a graphic card circuit board that it could almost be considered as a small stand alone computer. Like on the computer motherboard the graphic card is using its own clock circuitry to time each of the computed operations it perform, the graphic card also possess its own BIOS which like the computer motherboard can be software upgradable (Flash BIOS) or not and the graphic card circuit board also has its own self contained Chipset which in this case is referred to as the graphic Chipset and finally the graphic card also uses its own memory sockets. There are also some specific circuitry like the RAMDAC which is used to convert the digital signal form to an analog signal form as required by the graphic monitor as well as the expansion connector to allow the use of add-on card for additional feature like Mpeg acceleration, TV-Tuner, ect, ect..

The goal of this page is not to review every technical aspects of the graphic card but only the most important aspect that can be useful when its time to choose a graphic card. So, according to this I will try to mainly focus on these topics and give as much details as I can without being too technical.

These are in my opinion the most important criteria to consider when choosing a graphic card:

* The RAMDAC frequency
* The highest possible resolution
* The highest possible refresh rate
* The maximum memory allowed

Now we will have a quick look at some of the most important component used on graphic cards and we will try to see what are their importance on the overall performances of the graphic card.