PCI and AGP

[CivicRacer]

what the diffrence between the two other then where u put them in your motherboard ?

 

[sswingle]

Basically, PCI is a 33 mhz bus, AGP is.....much faster, meaning, more data can go to the AGP than to the PCI. Also, PCI is shared bandwidth on all your PCI cards, and AGP is dedicated to your graphics card.

I'm sure someone else can come up with something more technical than that...

 

[CombatChuk]

AGP was designed to eliminate the bottleneck that there was between the PCI bus and the memory controller. AGP runs at a faster speed and has direct access to the memory

 

[VIAN]

AGP or Advanced Graphics Port is a brown slot under your motherboard northbridge.
PCI or Peripheral Component Interconnect slots are white and are located at the bottom left of the motherboard under the AGP slot.

AGP runs at 66MHz while PCI runs at 33MHz. PCI cards share their bandwidth with all the peripherals of your system such as the HDD, Floppy, sound card, USB ports, basically anything that is connected to the motherboard. AGP runs on a separate bus which is quicker and provides some extra error checking on the data that it sends and gets to and from memory.

So, basically, an AGP bus is a quicker PCI bus with unshared bandwidth and better error checking.

AGP wasn't created because there was a bottleneck, it was created for storing textures faster and better than PCI. The need for storing textures in RAM was necessary in the chance that the game textures outweighed the video memory buffer, in which major slowdown would occur. Technically AGP isn't necessary with video cards that support large memory buffer, but it is good to have the potential or safety. As you can see here, there was very little performance differance if any between the PCI and AGP version of the Voodoo5 5500. Now, games are bigger and might require the VPU to send bigger amounts of data over the PCI bus and AGP could be at an advantage here.

I still recommend AGP until PCI Express comes out next year.

 

[CombatChuk]

There was a bottleneck in pci, the pci bus is limited to 133M/b a second which 5 years ago wouldn't have mattered. But a couple years later there was a few games that had bigger textures that would stress out the PCI bus (Unreal Tournament, Tribes, Quake 3). That made AGP more more handy.

 

[VIAN]

Ah, but I just stated that it wasn't created because the PCI bus had a bottleneck. At the time when the PCI bus was becoming a bottleneck AGP4X was out. So they had already been thinking about the future. And I also mentioned that with todays games, AGP will have an advantage in games because, now more information needs to be sent.

But I will give you credit for letting me narrow down that 2001 games and up would favor AGP because there would be a decent difference compared to PCI. In 2000, AGP vs. PCI was hardly ever a battle. And before that, there was no battle.