There are numerous considerations to make when choosing a Video Card.
Todays computer will almost certainly feature a video card built to fit in a PCI -E 16 slot.
AGP and PCI video cards have to all intents and purposes been superceded.
The main considerations when using such a card are likely to be:
a, The output potential of the card, both in visual and in video processing power such as rendering.
b, Any need for an Addition Power Supply to the video card?
c, Does the video card assembly occupy space below the PCI-E 16 slot?
d, The physical size of the video card.
e, Will the computer be used, now or in the future, with a Cross Fire or SLI configuration
f, Consideration of whether or not to use a liquid cooling system may be important if overclocking is to be used
if there is a need to avoid the loss of PCI or PCIe slot(s) when using oversized video card(s).
A, Output consideration.
Modern video cards go a long way to relieving the strain on the CPU.
(Central Processing Unit commonly referred to as the computer chip, or that ruddy great thing with a big fan)
Most users will want to see a high frame rate to get a realist fluid picture as they would expect when watching a DVD on a television.
There would seem to be little point however in having the ability to create higher frame rates that the human eye or monitor use.
Complicated frame content, fast action motion and high screen resolution all require a large throughput and needs additional consideration.
Hardware Rendering for video and 3D image processing is a major factor for video editing.
Picture quality, from a video card, should not be taken for granted. This may be especially so when High Definition viewing is required.
There are so many variables it is only prudent to list them all and see how one's requirements are met by specific video cards.
Searching out the Web Sites of Hi-Spec computer builder and scrutinising their computer specifications is often a good place to start.
But being mindful of their need to also supply good value may mean their choice may not be the best option for our build of computer.
My advice would be to use this Forum and seek the advice of professional and amateur members who will have up to date information.
B, Power Supply Requirement
High performance PCI-E 16 cards will often require an additional source of power as they are sometimes rated above that of the PCI-E 16 slot.
(Rating here is the power consumption of the video card)
The additional 12 Volt power source required will be supplied via a six or maybe even an eight pin socket wired direct from the Power Supply Unit
Via an adapter that plugs into the older large four pin type sockets that were commonly used to supply power for Hard Drives.
Plug & Socket commonly referred to as a Molex type
C, Space Requirement
Many high performance cards require additional cooling carried out by a fan and ducting system riding piggy back on the underside of the video card when in its slot.
This could result in the loss of a PCI or PCIe slot per video card.
D. The physical size of the video card.
With the ever increasing resources built into the video card they have grown in size, usually lengthways resulting in cards that may well exceed the computer case design.
Sometimes this can be overcome by sacrificing space intended for Hard Drives.
Ensure that a suitable computer case is chosen if this kind of card is chosen.
E, Cross Fire or SLI configuration?
The need for either of these is likely to depend largely upon the uses to which a computer will be put.
There is extensive coverage on the Internet, with both in-depth reviews and comparisons.
This link, though out of date already provides a good insight into the two systems.
Select the menu items and Click the ‘Go’ button to access all the information.
F, Liquid Cooling
This is essential in most cases where serious overclocking is to be undertaken.
The video card fan cooling system is replaced by cooling heads that clip onto the main video card processor.
This has the advantage of very efficiently cooling the processor without impinging upon the PCI card space below the video card socket.
Careful research would seem essential as the main processor is not the only source of heat.
There is lot’s of advice available on the internet.
The main computer CPU will also require consideration if overclocking is to be carried out and many over clockers strip off the CPU outer covering and attach the cooler direct to the chip found below. This will invalidate the guarantee of course.
The heated coolant, circulated in specially designed pipes, is passed through a radiator that is cooled by fans.
These can be fitted inside the computer case or externally with the added benefit of a noise reduction when sited correctly.
Liquid cooling is unlikely to be necessary for most of us.
PCI-E 16 Socket
New PCI-E 16 slot(s) are usually blue. Sometimes there is a second PCI-16 slot that may be black.
The blue No. 0, or top PCI-E 16 slot, should be used for the Primary Video Card.
When a second card is to be installed it should be in the lower No. 1, PCI-E 16 slot.
Note that the Primary No. 0 slot has 16 data channels whilst the secondary No. 1 black slot has only four or eight channels.
Enter the PCI-E (2) 16 ready Motherboard.
This will have two blue PCI-E (2) 16 ready slots each able to utilise all 16 data channels on each of the video cards.
Sometimes there may be a third black PCI-E slot.
Normally when using two cards they would be configured as a Cross Fire pair when using ATI based cards
an SLI configuration with Nvidia based cards.
The PCI-E (2) 16 ready Motherboard is able to take full advantage of two PCI-E (2) ready Video Cards to produce up to double that of a single PCI-E 16 Video Card.
PCI-E (2) 16 cards should work on a Motherboard that is not ‘PCI-E (2) 16 ready’
having only a standard PCI-E 16 slot.
BUT The Motherboard BIOS may require updating in such a case?
The Cards to be installed in the computer used in this guide.
This is not a general suggestion !
The selection of two:
Sapphire ATI Radeon HD 3870 XT, 512MB GDDR4, TV-Out/Dual DVI/HDMI (PCI-Express)
cards using Cross Fire, is based upon specific needs:
i, The hope for best quality output as well as a good frame rate for image intensive applications.
ii, Good quality direct output to a HD television and realistic playback on the computer of DVD creations.
iii, A preference for excellent hardware rendering and a good throughput for complex imaging at as near full quality imaging as seems to be currently practical
iv, Several other smaller considerations appearing in the specification of this card.
v, Value for money
This has tended to moved the video card preference away from the Nvidea Ge-Force 8800 GTX PCIe to the ATI 3800 series card.
Perhaps the main consideration is the prospect of far superior Anti Aliasing ability from the ATI card, in Cross Fire mode, which together with the above requirements would seem to make this card more suitable choice.
(Anti Aliasing and additional features help smooth out the sharp bits, pixelation and shimmering.)
To boost hardware rendering and complex imaging potential the Cross Fire video card setup is to be used.
Note also that ATI supply an excellent software, 'Catalyst Control Center', that enables simple control of most features and an Overdrive function to enable simple overclocking of the video cards.
Reading manufacturers specifications together with user’s reviews, has to be a good recommendation, along with comments and advice from current users.
There is excellent potential on our VFForum from which everyone can benefit, whether they want to make their own decisions in part, in full or based entirely upon other peoples opinions.
Maybe however that the more effort that one puts into the selection, the more rewarding will be the end product if one is satisfied with the result.
More importantly perhaps a far better understanding of the equipment will be achieved.
< Message edited by geoff_pell -- 1/5/2008 11:55:39 AM >