Being that the AGP 3.0 spec allows for 2 AGP devices...

[Yomicron]

Is there a reason why motherboard makers wouldn?t be able to have onboard video be one device and allow you to use an AGP card as the second?

There are many motherboards that already have onboard video and an AGP slot, but you can only use one or the other, so the manufacturing costs shouldn't go up much.

Do any modern chipsets have multiple AGP device capability? Is this feature required for AGP 3.0 compliance?


or do some modern boards already do this and I just didn?t notice it in the reviews?



EDIT: damn, I clicked the new topic button in the wrong window, this should be in General Hardware
EDIT2: Thanks Mod!

 

[jonmullen]

Thats a good questions, I would like to see the ability to use both

 

[ScrewFace]

I think we're gonna see, in the near future, mobos with 2 AGP slots where you can have 2 AGP cards of the same manufacturer running in SLI mode.

 

[BeauJangles]

Originally posted by: ScrewFace
I think we're gonna see, in the near future, mobos with 2 AGP slots where you can have 2 AGP cards of the same manufacturer running in SLI mode.

Excuse my ignorance, what is SLI mode?

 

[Lonyo]

Scan Line Interleave
AFAIR

Each card does alternate lines I think, not 100% sure. It was what could be done with 2 Voodoo 2 PCI cards back in the day, I'm not very knowledgeable on it though. Try google?


explanation

Scan Line Interleave (SLI) - 3dfx's patented ability to interconnect two graphics chips and alternate rendering individual lines. One chip handles rendering odd lines, while the other renders even lines. This not only makes faster framerates a given, yet with combined memory allows for higher resolutions. In the day of the Voodoo2, a serious gamer with a big budget most likely had an SLI setup, although for two-12MB Voodoo2 cards, it would run the consumer between $500 and $600 at launch, and they could still only play at 1024x768x16bpp!

 

[HokieESM]

My roommate and I, in undergrad, took our Voodoo2s and put them in SLI--that was seriously high-tech then.... but its really only good for fast-moving gaming. Not to mention, its like dual-processing--its not "twice" as fast as a single (there have to be "intercommunication" between the two cards).

I would prefer to see the ability to use a 2D card and a 3D card, if possible. I would love to have Matrox quality 2D (I was amazed when I put my G450 back in my machine after my 8500 went on the fritz).... and a good 3D card for either gaming or CAD. The ability to choose could be splendid. You know, something like the old Voodoo2 that did ONLY 3D.

 

[mechBgon]

I read into some of the AGP 3.0 specs. They still don't really think it's a good idea. Only one device can talk at a time on the AGP 3.0 bus, so there would probably be some hairy contention issues to iron out.

 

[chizow]

Originally posted by: mechBgon
I read into some of the AGP 3.0 specs. They still don't really think it's a good idea. Only one device can talk at a time on the AGP 3.0 bus, so there would probably be some hairy contention issues to iron out.

:Q

And we thought we had PCI sharing issues

Chiz

 

[Baronz]

Can't wait to run a dual GF FX setup

 

[Lonyo]

Originally posted by: Baronz
Can't wait to run a dual GF FX setup

In a server case and a mobo with 7 PCI slots so you still have some free slots for stuff like sound card?

 

[ProviaFan]

I would think that the dual device stuff would be for multiple processors on a single video card, as opposed to two separate AGP video cards. After all, we have perfectly good dual output (and even triple output) single-board video cards today.

 

[ProviaFan]

Originally posted by: Lonyo

Originally posted by: Baronz
Can't wait to run a dual GF FX setup

In a server case and a mobo with 7 PCI slots so you still have some free slots for stuff like sound card?

You forgot the pairs of spare earplugs so you don't become deaf.

 

[Lonyo]

Originally posted by: jliechty
I would think that the dual device stuff would be for multiple processors on a single video card, as opposed to two separate AGP video cards. After all, we have perfectly good dual output (and even triple output) single-board video cards today.

You mean like the (dead) company 3DFX?

 

[PCMarine]

Originally posted by: Lonyo
Scan Line Interleave
AFAIR

Each card does alternate lines I think, not 100% sure. It was what could be done with 2 Voodoo 2 PCI cards back in the day, I'm not very knowledgeable on it though. Try google?


explanation

Scan Line Interleave (SLI) - 3dfx's patented ability to interconnect two graphics chips and alternate rendering individual lines. One chip handles rendering odd lines, while the other renders even lines. This not only makes faster framerates a given, yet with combined memory allows for higher resolutions. In the day of the Voodoo2, a serious gamer with a big budget most likely had an SLI setup, although for two-12MB Voodoo2 cards, it would run the consumer between $500 and $600 at launch, and they could still only play at 1024x768x16bpp!

Hmmm interesting...That was before my time

 

[Soulkeeper]

don't forget the voodoo5....
sli on one board with two chips

 

[Yomicron]

If you were going to have two cards work together, wouldn't AFR be a better choice over SLI?



Due to the lack of demand, it's unlikely that there will be many (if any) boards with 2 AGP slots.

The reason I was interested in using onboard + the AGP slot would be for multiple monitor support. I would love to be able to buy an nForce board with dual integrated video, then add a dual head card and be able to use 4 monitors. It doesn't seem like adding this functionality would add much to the cost of a board, so I was just wondering if a system like will ever be implemented.

 

[Vadatajs]

Originally posted by: jliechty

Originally posted by: Lonyo

Originally posted by: Baronz
Can't wait to run a dual GF FX setup

In a server case and a mobo with 7 PCI slots so you still have some free slots for stuff like sound card?

You forgot the pairs of spare earplugs so you don't become deaf.

What's the point of having a soundcard if you can't hear it? LOL

 

[mechBgon]

Originally posted by: Yomicron
If you were going to have two cards work together, wouldn't AFR be a better choice over SLI?



Due to the lack of demand, it's unlikely that there will be many (if any) boards with 2 AGP slots.

The reason I was interested in using onboard + the AGP slot would be for multiple monitor support. I would love to be able to buy an nForce board with dual integrated video, then add a dual head card and be able to use 4 monitors. It doesn't seem like adding this functionality would add much to the cost of a board, so I was just wondering if a system like will ever be implemented.

Quad-head cards are not unheard of. STB MVP is one, IIRC. Or were you after quad-monitor 3D gaming...?

 

[Yomicron]

Originally posted by: mechBgon

Originally posted by: Yomicron
If you were going to have two cards work together, wouldn't AFR be a better choice over SLI?



Due to the lack of demand, it's unlikely that there will be many (if any) boards with 2 AGP slots.

The reason I was interested in using onboard + the AGP slot would be for multiple monitor support. I would love to be able to buy an nForce board with dual integrated video, then add a dual head card and be able to use 4 monitors. It doesn't seem like adding this functionality would add much to the cost of a board, so I was just wondering if a system like will ever be implemented.

Quad-head cards are not unheard of. STB MVP is one, IIRC. Or were you after quad-monitor 3D gaming...?

No not quad-monitor gaming, single monitor gaming would be fine. The 4 monitor thing would be good for productivity though.

I know that there are quad-head cards, but the cost is nice and high and they don't tend to be gaming cards. It would be much nicer to be able to pop in a regular dual head gaming card and have >2 monitor capability.

I was just curious as to why there aren't chipsets that support something like this, especially that now there is a spec that allows for it.

 

[mechBgon]

From what I read in the AGP 3.0 specs, it's not recommended. Read this if you can hack it or skip to page 66 of the PDF:

3.5 System Topologies and Specifications
As with AGP2.0, the AGP3.0 interface is a logical point-to-point20 network. The AC timings and electrical loading on the AGP3.0 interface are optimized for one active host component on the motherboard and one active AGP3.0 agent. More than two physical connections to the interconnect are not recommended since there is little timing margin for the added load, stubs and other signaling discontinuities. (mechBgon: by two connections, they mean the card and the northbridge here) If the interconnect is comprised of more than two loads and/or branching in the topology, it is the system designer?s responsibility to ensure compliance to this interface specification.

Interconnect and package requirements are explicitly called out in subsequent sections of this specification for the topologies listed later. This specification takes into consideration many concerns including different design cost constraints. For example, lower cost solutions can choose to utilize microstrip interconnect technology over symmetric stripline.

 

[ls32]

Considering how much of an issue memory bandwidth on current video cards, SLI between two video cards would not be a good idea. From what I understand the voodoo 2s running in SLI would render every other line, but if you add in AA modes, both cards would need to do extra samples and then the communication for doing the extra samples would most likely flood the channel between the AGP busses (Even with 8x) which would lower performance in general. I believe that the idea of having multiple video cards in the agp 3.0 spec was originally intended for workstations with 2 or more monitors so that every display could have 3d accelerated viewports without sacrificing speed on any of them.

 

[magomago]

Yeah, but 1024*768 in 1998 was VERY VERY impressive.


That and wan'st the point of AGP so there wouldn't be ANY sharing issues?

Wouldn't this be going down the same road again?