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DenverBuc
06-12-03, 02:42 PM
Hey, there is a pretty cool overview of PCI Express over at Anandtech. One thing I couldn't tell out of the article is this:

Will AGP be replaced by PCI Express?

Looks like with that bandwidth, GPU makers would be foolish not to - just don't know about competition for bandwidth.

Anyone familiar enough to venture an answer?

Nutty
06-12-03, 02:58 PM
As the RAM on video cards increases, and the ability to store vertex data in video card ram becomes more popular, then the need for a fast bus to the card becomes more redundant.

The only thing needing it now is basically dynamic vertex data, animations n stuff. As Doom3 and its engine do animations on the cpu, it means vertices have to be streamed from system ram to the gpu for rendering. Static world data will be held in video ram or AGP ram.

It will help yes, but the amount it will help will decrease as video cards get better, and become more flexable.

I can envisage a point when all models and scene data will be held purely local on the video card. The data bus will become comletely redundant after the data is initially uploaded when this time comes.

Dazz
06-12-03, 03:55 PM
Inother words yes it will replace it.

GlowStick
06-12-03, 05:00 PM
Also, PCI-Express is a real bus, AGP only supports video cards whle pci express can do any type of add in card.

The Baron
06-12-03, 05:04 PM
Also, PCI-Express is a real bus, AGP only supports video cards whle pci express can do any type of add in card.
Dunno about that... I think AGP COULD do other cards since AGP3.0 supports multiple devices.. but we'll never see AGP network cards. Would be kinda cool, though. :p

netviper13
06-12-03, 11:53 PM
The thing with PCI Express, at least what I got from the great article in the latest edition of CPU Magazine, is that each slot will have its own dedicated bandwidth; not shared like current PCI.

silence
06-13-03, 01:11 AM
well AGP 8x isn't used at all....and when it was introduced most ppl said it's just marketing cause there is no chance cards gonna need all bandwidth AGP 8x offers.....so if that's too much,i dun see why all the fuss about PCI express......

ya,i did start thread asking that...and got some answers, but i looked more i am still confused. i mean ppl are talking about like some sort of revolution coming, but truth is (from what i read around) that we simply won't be using all that bandwidth......am i wrong?

netviper13
06-13-03, 01:28 AM
PCI Express is definitely needed. Let's take Gigabit ethernet for example, all implementations of it prior to Intel's new method of integrating it were not able to run full-duplex Gigabit ethernet. Why? Because doing so would be more bandwidth than PCI can handle. Add to that a PCI soundcard and your PCI bus is more than saturated.

With PCI Express all those problems go away. Each slot has its own bandwidth thus it doesn't matter how many you fill, bandwidth is great enough to handle anything currently out there, etc.

Deimos
06-13-03, 01:32 AM
Originally posted by silence
ya,i did start thread asking that...and got some answers, but i looked more i am still confused. i mean ppl are talking about like some sort of revolution coming, but truth is (from what i read around) that we simply won't be using all that bandwidth......am i wrong? Yes and no. We won't be using all that bandwidth (for quite some time) as far as videocards are concerned. But you have to remember all the other devices. Gigabit ethernet. RAID storage solutions. I can easily create a PC where the PCI-bus is the bottleneck. So it's a revolution to get rid of the PCI-bus.

Unless all you want is the videocard, in which case it's a (possible unnecessary) evolution.

Mainboard design should also be simpler, because of (I presume) less lines to trace. Less lines (over the same area) means less crosstalk which then means that the speeds of the mainboards can be raised.

All in all I'm looking forward to it.

/Deimos

netviper13
06-13-03, 01:34 AM
There will still be quite a few lines to trace, but the serial nature of the design removes a lot of the nasty design requirements of parallel buses.

silence
06-13-03, 02:21 AM
well...ya, looks like i was just thinking about video cards, but when u put it like this i see advantages......thnx guys.

DenverBuc
06-13-03, 09:19 AM
Woohoo - got a thread in before it made it to the front page!!

Sniff, sniff....I'd like to thank all the little people who helped me get to this pinnacle of my posting career...

LOL.

Rampant CL
06-13-03, 10:17 AM
The needs of the many (add in devices) outweight the needs of the few (add in devices)

The dedicated bandwidth would be welcome

The Baron
06-13-03, 10:45 AM
PCI express gets rid of AGP, not PCI.

PCI-X gets rid of PCI.

yoladude
06-13-03, 05:19 PM
i think that maybe pci-express will be a good thing for replacing vanilla PCI slots and offering the extra bandwidth there, cause more bandwidth is actually NEEDED, as opposed to replacing graphics cards, as AGP 8x is already overkill for right now. i cant imagine the kinds of games that will need pci-express to function well.

Riptide
06-13-03, 08:27 PM
Originally posted by The Baron
PCI express gets rid of AGP, not PCI.

PCI-X gets rid of PCI.

So there will be motherboards that support both?

The Baron
06-13-03, 10:15 PM
Originally posted by Riptide
So there will be motherboards that support both?
Yes. PCI-X is backwards compatible with PCI so is the logical choice to replace PCI. PCI Express is not compatible with PCI at all (I don't think it's even pin-compatible), so it will replace AGP and MAYBE take hold someday.

Riptide
06-14-03, 12:07 AM
Is there a performance penalty for running a PCI-X and PCI board at the same time?