View Full Version : PCI vs AGP Graphics

02-12-2003, 08:31 PM
What is the speeds for PCI, and AGP 2x, 4x, 8x ?

Also how does PCI - X compare as well? I saw that new G5 had some PCI-X slots.


02-12-2003, 08:38 PM
From memory, AGP x 1= PCI x 1

AGP x 2 = double the speed of PCI.
AGP x 8 = 8 times the basic (66mHz?) PCI speed.

PCI-X runs at 133 Mhz, twice that of PCI (similar to AGPx2?) as long as its a PCI-X card in a PCI-X slot.


02-12-2003, 08:58 PM
Normal PCI is 33MHz, AGP is 66MHz.

AGP 2/4x use double/quad data rate to increase the bandwidth, but still run at 66MHz.

AGP also has the advantage easier access to main memory etc.

PCI-X is better than AGP, and will eventually replace it. For [desktop] PC land it will probably show up first in AMD64 systems (BTW, ATI will be releasing an AMD64 chipset when PCI-X arrives).

02-12-2003, 09:45 PM
so AGP 8x top of the line graphics cards, will be replaced by PCI-X graphics cards?

Will that make AGP cheaper, or not make much difference?

John Grieve
03-12-2003, 09:23 AM
PCI-X graphics cards will replace AGP eventually and I expect that at some stage AGP will be completely dropped from motherboards because of it.

While AGP is being phased out I would expect the prices to drop fairly fast until there is no AGP stock left to sell.

It is very difficult to pinpoint when this will start happening as PCI-X (even though it is backed by the big boys in the industry) has yet to get a grip on the market. I am assuming the first boards with PCI-X may still have an AGP slot but once the videocard manufacturers realise PCI-X is here to stay it will not be long till AGP is dropped from boards completely (I am assuming maybe 1 to 2 years max).