Tackling AGP 8X

EconolineCrush writes "AGP 8X is popping up in new chipsets and motherboards, and graphics cards are also starting to support the standard, but is there a major performance advantage over the older AGP 4X spec? According to this review of NVIDIA's latest AGP 8X-enable graphics products, no. The review also covers some of AGP 8X's new functionality, which includes support for multiple AGP ports with multiple AGP devices per port. Whether future games and applications take advantage of AGP 8X's extra bandwidth remains to be seen, but more interesting should be what companies do with multiple AGP devices and ports."

Comments

lack of performance

[Zod000]

I dont recall seeing much of an increase from agp 2x to agp 4x either so I'm no surprised

AGP8

[Nonillion]

That would be cool to have more than one AGP slot. I am sometimes disapointed that I cannot have two dual headed agp cards installed...

Hmm

[Maskirovka]

Is there anything preventing this new standard from being used for other peripherals like NICs and SCSI cards? If so, why not just phase out PCI completely?

Re:Hmm

[Fulcrum of Evil]

The bus is very one-sided. It gives 2.1GB/s to the card, but nothing particularly special on the way back. After all, the intent was to allow the cpu to stream from main memory.

Re:Hmm

[OverCode@work]

AGP is Accelerated Graphics Port, a very hackish specialization of the PCI bus for graphics devices. It is a master-to-target link, not a bus, per se. Its signalling rates are not be appropriate for a general-purpose bus (mobo manufacturers have enough trouble getting it right on the short runs to a single AGP port), and its optimizations are slanted toward squeezing performance out of bus traffic typical of graphics devices, not random access disk controllers and network devices.

Not to say that you *couldn't* have an AGP disk controller. But I doubt the performance improvement would be sufficient to justify the hassle and the lost AGP slot.

PCI-X is starting to come close to the lower AGP speeds in performance, and is a much cleaner and more general standard.

-John

A Quick Commentary

[clinko]

Granted, this is slightly off topic but worthy.

If multiple AGP is availiable for 8x then it's probably the greatest improvement possible. I ran 2 monitors at work, then got hooked. Now it's almost impossible for me to use 1 monitor. The problem is that you can't get multiple agps as of now so you have to use a crappy pci card.

This will also be awesome for gaming! I can't wait until I can get a dual agp card. I bet if they start making dual agp mobos then dual monitors will become very common.

The End.

Re:A Quick Commentary

[jedie]

I can't wait until I can get a dual agp card. I bet if they start making dual agp mobos then dual monitors will become very common.

three things:
1) Dual head AGP cards already exist, Matrox even has a triple head AGP card.
2) What's wrong with PCI cards? If you use it for work (like you said in the first part of your comment), I don't see what's wrong with it. I'm using 1 AGP and 1 PCI right now and I'm happy the way it is. usually I use my main monitor, which has a higher resolution, for coding and at the same time my second screen is cluttered with IRC, IM and online-documentation
3) I don't think dual AGP slotted mobo's will become standard real soon: people have lots of PCI slots and that din't encourage people to go dual/triple/... screen. I rather think that dual AGP will remain something for techies, geeks and professionals.

And remember kids: the more monitos you have, the larger your penis is!

Confused

[El Pollo Loco]

It's been a long weekend, but this part still confuses me.

which includes support for multiple AGP ports with multiple AGP devices per port.

I can't figure out why this would be good. (this is not a troll, i just can't figure it out). Can you put two video cards in, and have them work together, like voodoo SLI type things? Or is it just one card for a monitor, another to output to tv?

Overkill?

[bogie]

Call me when we actually need more than AGP 2X. I've seen a lot of tests which show only the minor differences between AGP 2X and 4X. Its nice to know the bandwidth will be there, but this is one of those technologies like Serial ATA which really won't be showing its potential for a few years. Of course that won't stop the marketing gurus from tellig people AGP 8 is a "must have".

SLI BACK AGAIN?

[LoRdTAW]

Remember VOODOO 2's SLI feature that we all so loved? Well it was AGP that
halted its implementation into more modern cards. Now with multiple AGP ports and
multiple devices per port, SLI may soon be back.

Re:What (cool thing) could you do w/multiple devic

[ngoy]

In gaming, you could use multiple POV's in flight simulators (I think M$ flight sim supports three monitors, IIRC), or racing (Front, left, right). In desktop publishing it is usful for seeing two pages at once, or four pages at once depending on what resolution you are using.

At work I leave Outlook open on one all the time, have Visual Studio open on that one and an Internet Exploder screen open on the right screen. That way when I make changes in VS on the left I can instantly refresh the IE window on the right without doing all the toggling back crap.

I also used to do reports and presentations. Having dual monitors allowed me to have Excel/Access/whatever source program open on the left, and Powerpoint on the right. I could drag a chart from Excel full size and drop it into Powerpoint without having to do cut/alt-tab switch window/paste. Much easier, gives WYSIWIG some credence to its name.

I am running dual monitors on an NT4 box with 2 Matrox Millenium PCI's (have had dual monitors for 4 or five years now I think on that one). My other box has a Matrox G450 AGP and a Matrox PCI Millenium for dual capability on it (W2K).

IMHO, Matrox makes the best multi-display drivers/cards at a reasonable price and have had them for quite a long time compared to the others. They have a quad output card also but it is costs a bit more than the duals.

ngoy

Stop thinking graphics

[smugskii]

My wishlist (primarily as a server tech guy) does not concern squeezing a bit more graphics out of the bus.
Personally, I would like to see that bandwidth used for other accellerators, such as SSL accelleration like nCipher provide. Or how about a Java non-virtual machine? I'm sure many games could benefit from a dedicated AI board, possibly using FPGA (field programmable gate arrays) so that some especially tricky AI functions could be off loaded from the CPU. To put it short, we already have stunning graphics, which will continue to evolve no matter what you think about the tweaks to AGP. What I hope the more imaginative of you are thinking, is what else could be done with this?

Re:Stop thinking graphics

[Junta]

Why the hell would you need that sort of bandwidth for a SSL accelerator? Even if you were using it for Hard Disk I/O, Hard Disk I/O goes throuh the PCI bus, so it would not be saturated. For the most reasonable area of network usage, bandwidth on any PC equipment wouldn't go anywhere near such a need. For bigger needs, you probably need bigger equipment anyway. Don't think a dedicated Java processor would be a big seller, especially with the speedups in implementations seen as of late. AI hardware may sound intriguing, but it is so unsexy in terms of consumer visiblity. That, and methods to AI frequently change.

No, the place where the bandwidth has the most impact on the user experience remains the graphics. They look pretty nice nowadays, but until you see scenes generated on the fly at 60 fps or more that are indistinguishable from real life, graphics will always be lacking.

Re:Stop thinking graphics

[AvitarX]

The barrier to ultra hyper realistic on the fly graphics at 60 fps will never be the graphics (IMHO). It will be the movement. Wasn't there an article here once about how cloth will be nearly impossible to realistically render?

How about the way people move? Graphics card will be able to on the fly render something that looks true to life frame by frame, long before the PC will be able to feed the correct movements too match.

The limit of our ability to model movement is painfully obvious in the final fantasy movie. many stils were true to life in newspaper quality color depth and resolution, but most of the scenes were awkward. When the graphics get too good is when these movements become more annoying, think Toy Story vs Final fantasy. Or even the semi realistic princess in Shrek, it was just horribly awkward, but with less graphics, or very unreal (such as Shreck himself, or any of Monsters, inc) the movement does not stand out as much.

Multiple AGPs....

[Steveftoth]

Ok, first off AGP is an Accelerated Graphics Port. Notice that it is a PORT not a Bus. This means that in order to have more then one AGP Port, you would have to have more then one PCI bus. Since all the implementations of AGP share with the PCI control functions. It would be very difficult to just simply add more then one AGP port to the PC system, little things like the operating system would need to be updated, it's not like a simple bios tweak can handle it. There are already many problems with the current agp system. I'm sure some ofyou remember the whole fiasco with AMD and the AGP GART system tweak that was causing Linux to crash, but not Windows because AMD told MS to shut it off.
Anyway, I too would like multiple AGPs on my motherboard, but it would take more then a smart vendor to make it a reality. Intel designed the AGP as a stopgap, temporary solution for the lowest common denominator. And it still works well if you only need one monitor.

Does AGP offer *any* advantage?

[swordgeek]

Please forgive my ignorance. This is an honest question.

At the time that AGP first came out, I was under the impression that its primary advantage was to allow a direct pipeline to system memory, if you ran out of on-board RAM.

Then RAM got really REALLY cheap, and we went from 4-8MB onboard to 32MB, almost overnight. Now you can get video cards with 64MB and even 128MB.

I can't imagine games using more than 128MB of texture RAM, and so I have to wonder why AGP is still being developed. What else does it offer?

Re:What (cool thing) could you do w/multiple devic

[DeComposer]

I'm currently using a six-monitor configuration for music production. I have Sonar spread over four 19" monitors and I use two 17" monitors to display virtual intruments/effects and the MOTU console.

3D isn't a factor on this machine, but it's tricky to get three (one AGP, two PCI) dual-head displays to work side by side correctly.

Two AGP slots would permit me to use just two Parhelia (or competitors'--once they jump on the triple-head bandwagon) cards and free up PCI slots for more useful things like DSP cards.

Then, too, a configuration like that would make for a breathtaking multi-monitor gaming experience!

Re:shouldn't be called AGP anymore then

[Anonymous Coward]

A bus can handle about 100 people or thereabouts. A port can handle thousands of people at any given time.

You tell me which one is bigger.

So is it any better to have faster AGP?

[WolfWithoutAClause]

Well, a bit, sometimes; but mostly no. First you have to realise that modern graphics cards have a tonne of on-board memory. The on-board memory is used to store the current view, another view that the card is rendering (which is switched to only when complete to avoid flicker) and the distance that each pixel is from the user (the z-buffer). It also stores flattened out texture maps that the graphics card rotates into place on the rendering buffer.

The texture maps usually take up the most memory, and they can change depending on the position of the player and even which direction he is looking in.

The position of the objects is sent every frame but shows less variability.

But the texture maps need to be transfered into the graphics card memory once before they can be rendered.

So this happens initially when the texture first appears, but after that its in the memory and it doesn't need resending after that until it is flushed if it is no longer in view and something else needs the space.

But just occasionally new textures are needed. For example sometimes in say, half-life I used to spin around and the screen would stop updating for maybe 1/8 of a second. What was happening was that the wrong textures were in the graphics card and they were being pushed down the AGP-1 pipe as fast as it could take it- not really fast enough- I'd often get a rocket launcher up me; the screen would have stopped updating for just a moment.

Of course now the graphics cards have more memory, the software may be written better so that textures get preloaded before they are needed, and probably most or all of a levels textures fits into the card buffer anyway. So all in all- little or no waiting when spinning around; and the AGP is now x4 as well so instead of 1/8 second we are looking at 1/32 worst case; only 32 milliseconds, which for a one-off jitter isn't perceptible.

John Carmack has talked about the idea of generating texture maps dynamically. If he were to implement this, then AGP would be much more important. Right now, precalculated, fixed texture maps are much more common in games. Bottom line- who cares about agp x8; it's like ata133 it makes no difference to nearly everyone.

Re:What (cool thing) could you do w/multiple devic

[Steveftoth]

Maybe he's almost blind from all the radiation comming off of the 3 20 inch monitors he's got on the desk?

Or maybe he's just an american, probably drives an SUV too. ;)

Draw!

[qnonsense]

• Don't buy ATI Radeons for duel-head! I have an ATI Radeon 9000 Pro and the second monitor has a shadow on it, not unusable, but annoying.

Of course there's a shadow on it! With Duel-Head, your monitors are too busy slapping each other with white gloves, demanding satisfaction and poping caps at each other at high noon!! With all the tumbleweeds blowing by, how can you expect those poor GPUs to actually refresh their frame buffers!!

Oh, I get it!!! You meant Dual-Head!

Nevermind. My bad.