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Skip Breakfast · Nov 9, 2004, 02:13 PM

I know that some of you are up on what's going on with the dark side.

I've been seeing a lot of new video cards going with high-speed PCI-X instead of AGP, and I've spoken with a few folks who have told me that it makes better use of bandwith than AGP.

I suppose this means Apple will cease including AGP slots in future Power Macs, but not for a while. Now I'm wondering if this is another reason for the switch from ADC to DVI.

Your thoughts?

Leonard · Nov 9, 2004, 02:29 PM

Video cards are NOT going PCI-X, video cards are going PCI-E or PCI-Express!

PCI-E will most likely appear in PowerMacs in one of the next two revisions. Of course ATI and Nvidia will continue to manufacture AGP cards for the next couple of years for the billions of PCs and Macs that still have AGP and want to upgrade.

If you ask my opinion on the switch back to DVI, it's because ADC didn't catch on and also because of the introduction of dual DVI which is needed on bigger LCDs.

Skip Breakfast · Nov 9, 2004, 02:46 PM

My bad. I meant PCI-E.

I didn't realize that ADC was single link. That explains a lot.

CatOne · Nov 9, 2004, 05:56 PM

Originally posted by Skip Breakfast:
I know that some of you are up on what's going on with the dark side.

I've been seeing a lot of new video cards going with high-speed PCI-X instead of AGP, and I've spoken with a few folks who have told me that it makes better use of bandwith than AGP.

I suppose this means Apple will cease including AGP slots in future Power Macs, but not for a while. Now I'm wondering if this is another reason for the switch from ADC to DVI.

Your thoughts?

PCI Express is different than PCI-X, as was explained. Not sure of the exact rates, but the current PCI Express slots being used for video cards in PCs are 16x, which are about twice as fast as the 8x AGP slots.

I'd predict that PCI Express will become the "standard" connector going forward, so that in 5 years everything will be using some version of it. It addresses a lot of the shortcomings of plain old PCI.

Scotttheking · Nov 9, 2004, 06:32 PM

Originally posted by CatOne:
PCI Express is different than PCI-X, as was explained. Not sure of the exact rates, but the current PCI Express slots being used for video cards in PCs are 16x, which are about twice as fast as the 8x AGP slots.

Yep. AGP 8X is 2.1GB/sec, PCIe is 4GB/sec. But there are other differences, a major one being that the card can send data back far more easily.

jamil5454 · Nov 9, 2004, 09:46 PM

Today's video cards are just making use of AGP8x, much less PCI-E. I'd wait until the next gen. of cards come out to upgrade to a PCI-E based system.

macgfx · Nov 10, 2004, 12:45 AM

Can we not have cake, and eat cake as well?

1xAGP PRO SLOT
2xPCI-E SLOTS
2XPCI-X SLOTS

All bets are covered.

OR is there something about PCI-E and AGP that would conflict?

Scotttheking · Nov 10, 2004, 09:57 AM

Originally posted by macgfx:
Can we not have cake, and eat cake as well?

1xAGP PRO SLOT
2xPCI-E SLOTS
2XPCI-X SLOTS

All bets are covered.

OR is there something about PCI-E and AGP that would conflict?

Cost. You'd only use one or the other, but pay for both. It would make sense to transition to PCIe, as PCIe cards are now out. Hopefully Apple will be smart and go to something like 1 16x, 1 4x or 8x, and 2 PCI-X (Wishing for a reasonable amount of slots is folly).

polendo · Nov 10, 2004, 12:03 PM

I believe PC gamer of november (and/or PC World) did some test regarding this issue. In a nutshell: while PCI express does have a huge advantage on the use of bandwith, the truth of the matter is that AGP 8x is MORE than enough for TODAY's games (or apps). In other words the bandwith of AGP's exceed's by far the requirements of the games. They in fact showed that the tests turn out the same fps on a game +/-1 or so (using the same chipset of nvidia'a and ati's) with both AGP and PCIE.

I think that PCI E will open new possibilities in the near future, but as in today AGP is enough because is not used 100% of its capacity. In a PC world, I would switch to a PCI E based board if I needed to upgrade my whole system.. but if I had a capable motherboard with 8x , I would only switch to an AGP videocard because the difference in performance is marginal (if at all).

jamil5454 · Nov 10, 2004, 04:27 PM

Originally posted by polendo:
I believe PC gamer of november (and/or PC World) did some test regarding this issue. In a nutshell: while PCI express does have a huge advantage on the use of bandwith, the truth of the matter is that AGP 8x is MORE than enough for TODAY's games (or apps). In other words the bandwith of AGP's exceed's by far the requirements of the games. They in fact showed that the tests turn out the same fps on a game +/-1 or so (using the same chipset of nvidia'a and ati's) with both AGP and PCIE.

I think that PCI E will open new possibilities in the near future, but as in today AGP is enough because is not used 100% of its capacity. In a PC world, I would switch to a PCI E based board if I needed to upgrade my whole system.. but if I had a capable motherboard with 8x , I would only switch to an AGP videocard because the difference in performance is marginal (if at all).

^What he said.

drHo · Nov 10, 2004, 10:51 PM

but isnt PCI-E needed for the SLI configurations currently offered by nvidia, and i'm sure ATI is not far behind. like this one:
http://www.alienware.com/intro_pages/sli.aspx

DAMN! if i only had the money....wowser!

UnixMac · Nov 13, 2004, 09:25 AM

Bt the time software is available that can tax today's 8X AGP top end GPU's like the 6800 and 9800, we'll all be using new Mac's with PCIe only bus or something newer.

The progress of bandwidth has far exceeded the progress of CPU/GPU performance increase. Additional bandwidth without the added processing power is meaningless.

polendo · Nov 13, 2004, 09:33 AM

Originally posted by drHo:
but isnt PCI-E needed for the SLI configurations currently offered by nvidia, and i'm sure ATI is not far behind. like this one:
http://www.alienware.com/intro_pages/sli.aspx

DAMN! if i only had the money....wowser!

Actually you are correct on this point. SLI would allow more processing power (2 GPU's) to be used with the greater bandwith.

regards

UnixMac · Nov 13, 2004, 11:12 AM

Originally posted by polendo:
Actually you are correct on this point. SLI would allow more processing power (2 GPU's) to be used with the greater bandwith.

regards

SLI is a whole different animal... but then you have a major cost issue for (some)... two Nv40 cards are going to be north of $1000... now you're turning a whole new direction in graphics for professional and super high end gaming I suppose.

Imagine SLI NV40 with dual 30" ... man that would be nice.

istallion · Nov 16, 2004, 12:28 AM

Originally posted by UnixMac:
SLI is a whole different animal... but then you have a major cost issue for (some)... two Nv40 cards are going to be north of $1000... now you're turning a whole new direction in graphics for professional and super high end gaming I suppose.

Imagine SLI NV40 with dual 30" ... man that would be nice.

I think the reason most people welcome SLI is the upgrade path. Waiting until your first card gets too slow and picking up it's mate for cheap in a year.

P · Nov 18, 2004, 11:35 AM

Another advantage of PCIe is the ability to add a second video board on it - you can't do that with AGP, so the second board has to be PCI (which of course is much slower). You can reuse your old PCIe board as a secondary board. When that 6800U just can't cut it any more, buy a new 8800 (or whatever) and use the 6800 as the secondary board. Kinda nifty.

jcadam · Nov 18, 2004, 02:19 PM

Originally posted by P:
Another advantage of PCIe is the ability to add a second video board on it - you can't do that with AGP, so the second board has to be PCI (which of course is much slower). You can reuse your old PCIe board as a secondary board. When that 6800U just can't cut it any more, buy a new 8800 (or whatever) and use the 6800 as the secondary board. Kinda nifty.

The way SLI works now (and the way it worked back in ye olde days of PCI), both cards have to be a matched pair (They both have to be 6800 Ultras, etc.), the card and drivers have to both support SLI too, etc. etc. The difficulties in getting two differently-performing cards (even if the only difference is clock rate of the GPU and/or memory) to sync correctly are non-trivial.

Of course there is some overhead, you don't get a doubling of performance by adding a second card.

Only rich bastards can afford an SLI setup, since you have to be able to afford TWO high end grafx cards (low end cards in an SLI config would be pointless, just buy ONE high-end card!!)

You are better off getting a 6800 Ultra now, in a year, ditch it and buy an 8800 (since even if it doesn't quite outdo your dual 6800 performance-wise, it'll probably support more features (later versions of OpenGL, Direct3D, etc) anyway).

There are only a few motherboards out there right now that can support SLI also, since you need TWO 16x PCIe slots (most only have one). If Apple chooses to provide this capability in the next PM revision, I'll be very surprised (since few people would be interested).

That's why my whole opinion on SLI is, well, meh

Leonard · Nov 18, 2004, 03:00 PM

jcadam, what I think the previous poster was talking about was having 2 PCI-E cards NOT in an SLI configuration. Just having 2 PCI-E cards working separately giving you the ability to have one monitor running on one card and a second (or third) monitor on the second card. Ie. With our current system of 1 AGP slots and 3 or more PCI slots, when you replace your AGP card with a newer card, you can't use the old AGP card in the PCI slot, but if you have two PCI-E slots, your old PCI-E card isn't useless, it could be used in the second PCI-E slot for a second video card NOT in SLI.

jcadam · Nov 18, 2004, 03:19 PM

Originally posted by Leonard:
jcadam, what I think the previous poster was talking about was having 2 PCI-E cards NOT in an SLI configuration. Just having 2 PCI-E cards working separately giving you the ability to have one monitor running on one card and a second (or third) monitor on the second card. Ie. With our current system of 1 AGP slots and 3 or more PCI slots, when you replace your AGP card with a newer card, you can't use the old AGP card in the PCI slot, but if you have two PCI-E slots, your old PCI-E card isn't useless, it could be used in the second PCI-E slot for a second video card NOT in SLI.

oh ok. But in that case you would still need a second 16x PCIe slot. What I expect to see in the next PM revision is one 16x PCIe slot, and a combination of PCIe 1x slots and traditional PCI slots (or PCI-X) for legacy support.

But now I'm off-topic, so I'll stop.

awcopus · Nov 18, 2004, 07:10 PM

Originally posted by Leonard:
jcadam, what I think the previous poster was talking about was having 2 PCI-E cards NOT in an SLI configuration. Just having 2 PCI-E cards working separately giving you the ability to have one monitor running on one card and a second (or third) monitor on the second card. Ie. With our current system of 1 AGP slots and 3 or more PCI slots, when you replace your AGP card with a newer card, you can't use the old AGP card in the PCI slot, but if you have two PCI-E slots, your old PCI-E card isn't useless, it could be used in the second PCI-E slot for a second video card NOT in SLI.

Leonard, I couldn't help but notice that your system is virtually identical to mine... except for the 9800XT. Would you (or anyone else) mind recommending a reliable vendor for the 9800 XT? I ordered one over the phone with MacMall, and they sent me a special edition. So, I'm looking again. Thanks in advance.

I had considered waiting for the X800, but I'm too impatient to see improved performance with Motion. I would have considered the nVidia 6800, but my ADC-based 23" display is a limiting factor.

UnixMac · Nov 18, 2004, 11:21 PM

Speaking of SLI.. I remember my Obsidian X-24 by Quantum 3D ... man that was a large card! At that time, it was the undisputed top dog. I wish they made cards of that pedigree today.

Leonard · Nov 19, 2004, 12:17 PM

Originally posted by awcopus:
Leonard, I couldn't help but notice that your system is virtually identical to mine... except for the 9800XT. Would you (or anyone else) mind recommending a reliable vendor for the 9800 XT? I ordered one over the phone with MacMall, and they sent me a special edition. So, I'm looking again. Thanks in advance.

It's unlikely you'd find a vendor, since the 9800XT is an OEM card. It's only made for Apple and only available as a BTO (or CTO) on new G5 PowerMacs. Apple doesn't sell it as an individual part. The 9800 Pro Mac SE is the only retail card close to it - I'm not sure if the 9800 Pro Mac SE is clocked the same or not. You could try finding the 9800XT on eBay or from an Authorized Apple Service Provider (AASP). The AASP might be willing to purchase it as a repair part.

l008com · Nov 20, 2004, 10:59 AM

I welcome the change back to PCI for the same reason that was mentioned above. I have two monitor on my one AGP card, and if i want a 3rd monitor, which I do, I'll have to settle for a cheap ATI PCI card that will be vastly unaccelerated compared to the two screens I already have. And with 10.4 moving more and more graphics stuff to the card itself, the difference would really show. Thats my take on it. Of course I wouldn't mind an nVidia AGP card that could simply drive 3 monitors :-P

P · Nov 21, 2004, 08:03 AM

Originally posted by jcadam:
oh ok. But in that case you would still need a second 16x PCIe slot. What I expect to see in the next PM revision is one 16x PCIe slot, and a combination of PCIe 1x slots and traditional PCI slots (or PCI-X) for legacy support.

But now I'm off-topic, so I'll stop.

Leonard was right, that was what I meant. And you don't actually NEED a PCIe 16x slot - if you have a 8x slot (and many PC boards today have one 16x and one 8x slot), the board will work there. Slower, yes, but as has already been stated, 16x is more than the boards can use right now. It will even work in a 2x or 1x slot. At that point, performance will be impaired, but still faster than PCI, and you get it "for free" if you reuse the old board.