AGP vs. PCI

[miwojo11]

What is the big difference between PCI and AGP as far as graphic cards go? I searched it via google and most websites said that AGP was faster, but the topics were years old. I also noticed that most new cards only come out via PCI. Which one is faster?

 

[MarkG]

PCI-Express is totally different to PCI.

As for speed, if the chips on the card are otherwise identical and they're fast enough to be bus-limited, PCI-Express > AGP > PCI.

 

[Darkchyld]

3 interface standards for video currenyly exsist...
PCI, 133 mhz max transfer speed, oldest, slowest.
AGP, in 2x, 4x and 8x. (x=PCI Bus speed) On its way out.
PCIx, or PCI Expess. The latest and greatest. 16x.
What it all comes down to is how fast can data be moved to the video card. Todays game are so graphicially intensive that the major bottleneck in performance was the cards interface. With SLI and CrossFire the latency has been reduced to a minimum.
When your sitting there waiting for a game like Quake 4 to "load", what happening is the texture data is being decompressed from the harddrive and loaded into your graphic cards RAM, (of course theres data being loaded into the system RAM too). As one plays the game as the screen changes data moves back and forth, the more "bandwidth" or speed the better.

 

[Pain]

Slight correction, PCI = 33Mhz, with 133MB/s max bandwidth.

There used to be 1X agp, but that went away almost as fast as it appeared.

PCI-EX is a replacement for PCI, and replacement of AGP came along for the ride, with a lot of misinformation feed to the public about the lack of bandwidth on AGP and therefore a jump to PCI-EX was required [for video]. I'm not saying PCI-EX isn't good, but there was a lot of marketing spin hoopla that went into selling PCI-EX as the savior of AGP.

The load times of games is largely due to trying to suck 10 gallons of water through a soda straw, i.e. reading the disk. It's not due to the graphics card interface.

 

[Darkchyld]

Absolutly correct! Thank you for the clairification! :lol:
DC

 

[TheGreatGrapeApe]

PCI-EX is a replacement for PCI, and replacement of AGP came along for the ride, with a lot of misinformation feed to the public about the lack of bandwidth on AGP and therefore a jump to PCI-EX was required [for video]. I'm not saying PCI-EX isn't good, but there was a lot of marketing spin hoopla that went into selling PCI-EX as the savior of AGP.

I'd agree for single card, but the lack of dual card option for AGP and likelyhood that quad SLi/Xfire would saturate AGP is realistic seing as it's not able to scale similarly.

 

[Pain]

Yeah, that's true. When the new interface was first announced SLI wasn't around yet, but you are certainly correct that it is now.

 

[Stevemeister]

PCI = old and slow. Not many cards around and quite honestly not up to playing latest games at anything more than about 800 x 600 tops

AGP = faster amd a decent AGP card will play new games adequately but AGP is now being replaced by PCIE.

PCIE = latest and fastest. Don't get anything else if you're buying new

 

[tenaciousleydead]

the only thing you really need pci-express for is HDTV streaming where it acctually comes in handy.

 

[MarkG]

Note that there was also 66MHz PCI and 64-bit PCI and probably other variants that I've forgotten. But the odds of having anything other than 33MHz 32-bit PCI in a consumer PC are slim .

the only thing you really need pci-express for is HDTV streaming where it acctually comes in handy.

AGP4x is kind of borderline for HDTV, but I watch and edit a lot of 1080i HDTV footage on this machine (except it has to be converted to 540p at 50 or 60fps for smooth playback).

 

[parlee]

i dun think what u guys r saying about the bandwith is true, sure pci-express has double, but if u look at the latest cards for agp on a 4x interface and an 8x interface the difference is litterally less than 2%, which could be due to a margin of error... 16x bandwidth for one card is total overkill, even with the 7900gtx, they could make it on agp with a bridge... but there trying to force people to upgrade so that they can turn a bigger profit.. kinda lame since im still on agp. a 7900gtx on 4x agp would run almost identical to a 7900gtx on pci-express 16x... maybe when nvidia 8xxx series and ati 2xxx series come out then the 8x bandwidth will be close to its maximum, but i guess companys wanted 16x out so that they could help push video card makers.. or to make more money :lol:

 

[MarkG]

but there trying to force people to upgrade so that they can turn a bigger profit

No, they're trying to force people to upgrade because AGP is dead, dead, dead.

Try talking to a hardware engineer sometime about AGP8x with its octuple-clocked 66Mhz bus, and see how much they shudder at the idea of trying to get it all to work . Hardware-wise, AGP is a nightmare: certainly there would never have been an AGP16x bus whereas there's plenty of room for faster PCI-Express buses.

 

[Grimmy]

Noooooooo...

dissassemble....

845.... is still.. alive!!!!

I still like my AGP... :roll:

 

[MarkG]

Well, I still use an AGP4x 845 machine here, but I have no illusions about the future. AGP was a bodge that worked for a while, but it's time to switch to something that's designed for the future.

 

[Darkchyld]

845.. ? Is that a chipset?
Right now one can't saturate an 8x PCIx bus let alone the 16x but the time will come. I can still hear,"What! You can't clock a CPU at 1000 Mhz!".
Profit? It the way of business. What else do you get?
Bragging rights. Mines faster, bigger, better than yours.. :lol:
And whats the one thing that the enthusiast will pay for?
More, MORE!!
DC