|
|
|
|
|
Web Developer's Journal Archive SectionThis article is out of date, but may still be useful to some readers.Kelvin 64by Paige Turner |
||||||
|
The performance of any graphics system is, for the most part, determined by the video card and the heart of any video card is the graphics controller chip. Information is constantly passed back and forth through the graphics controller as images are updated on the screen.
This constant swapping means that the bottleneck will usually be the interface between the memory and the graphics controller. The Kelvin 64 was one of the first video cards to use a 64 bit data path - speeding up data transfer rates, effectively doubling the amount of information that can be passed through the interface. 32 bit video cards are probably even today the biggest selling type of card but anyone seeking real graphics performance should be looking instead at 64 or even 128 bit cards. If you work in front of a computer for a living, you are aware how much time (read: money) can be wasted waiting for screen redraws. Investing in a high end video card pays back in a matter of months rather than years as productivity increases. Of course there are other things that influence video speed. The amount and type of memory on a video card is a major factor as well as the way the memory is addressed. You've probably spent significant amounts of time waiting for screen redraws and noticed that most large graphic images redraw in "chunks" or pieces. An application calls for a graphic to be drawn and the video card grabs as big a chunk of the image as it can, draws it and then goes back for another chunk of the image. Complicated graphics can use quite a few chunks of data and take quite awhile to draw. The more memory you have on your video card the larger the chunks that can be redrawn at a time. The faster your memory is the less time it takes to do that redrawing. There are two main types of video memory. DRAM and VRAM. VRAM is the fastest but rarely seen in video cards except in the very high end. If your wallet is fat enough to handle the load, insist on VRAM for your video card. DRAM is much more common and is fast enough for most uses. Two megabytes of either type of video RAM are a minimum for acceptable graphics performance. Four would, obviously be better (bigger chunks of data at a time). A few high end cards can hold 8 MB of VRAM or DRAM. Another method of speeding up video performance is used in the Kelvin 64. Linear addressing maps the computer's system memory to the memory on the video card. This should allow for an entire graphic to be built in one piece instead of in chunks. Non-linear addressing can take many more CPU cycles to load and unload chunks of graphic data while an image is building. The Kelvin 64 with linear addressing should outperform some 64 bit cards even with VRAM. The Kelvin 64 is available in three versions: VL, PCI or ISA and is compatible with drivers for Windows 3x and NT, OS/2, AutoCAD, Microstation, and MS-DOS applications. It supports a maximum 1280 x 1024 resolution at 256 colors and 60 Hz. It is capable of a maximum of 75 Hz at 1024 x 768 and 65,536 colors. It lists for $250 with 1 MB of DRAM and is the 2 MB version sells for $325. This is not a bad price at all for a 64 bit card. Being able to upgrade to 4 MB would, however, be a nice option. If you have an older, slower system the Kelvin 64 would be a good way to increase performance. Most VL or PCI computers bought from reputable manufacturers will probably already have a pretty fast video card so it would be wise to get an idea of what you already have before you plunk down the dollars for a video card upgrade. If you have a 32 bit card with 1 or 2 MB DRAM you may not notice a big difference after installing the Kelvin 64 or a similar card. If you have a 16 bit card or one with 1 MB or even .5 MB you will almost certainly sit up and take notice when your new Kelvin 64 starts up. But be light on your feet. The video card market is constantly changing. One manufacturer leapfrogs another with new video technology almost weekly. By the time you read this Orchid may well have a faster, better card available. The video card market is very hard to keep up with. Being timely is difficult and you - getting ready to pop for a fast video card - don't want to waste your money. So, just before you buy, check out the latest computer magazines for comparative reviews of video cards. S t r e t c h your wallet or credit card and get the best card you can find and get as much DRAM, or even better, VRAM, as you can possibly afford. If you don't - you may find yourself disappointed in the lack of a visible improvement over the video card you started out with. The market changes so fast that you will also find yourself regretting your hasty purchase with too little video RAM. Sure you can add video RAM to some cards later on but again, you probably won't be able to notice much difference if you are only adding 2 more MB of DRAM. Go hog wild upfront - go for a 64 bit card with at least 2 MB of DRAM. The Kelvin 64 is a good buy at $250. |
| Advertising Rates & Policies | Contact | Subscribe to Our Mailing List |
Webmaster
|
Web Developer's Journal |
