Mulitple PCI-Express 16 slots

[SoCalBoomer]

Was wondering if anyone had heard any rumors/thought of anyone who might possibly even consider putting multiple PCIx-16 slots in? I run 3 monitors now at work and 2 at home with my primary always alone. . .with AGP going to PCI Express-16, it would be nice, neh?

 

[Peter]

PCI Express is not a bus system, all connections are point-to-point. So unless some vendor comes up with a chipset that has multiple x16 links, we won't see that.

 

[ProviaFan]

Sun has multiple connectors for their proprietary graphics cards in a few of their workstations. I've heard rumors of a few rare Itanium workstations that were made with dual AGP slots (not sure if this system is real, but apparently the latest AGP spec allows for it in theory). I'm sure someone will make a motherboard with multiple PCI-Express x16 slots, but whether the public will be able to buy it or not is anyone's guess (e.g. 8-way Xeon boards are made, but try to order one from Newegg).

BTW, PCI-X is the latest revision of "normal" PCI 64 bit, that runs at up to 133MHz. PCI-Express is properly abbreviated PCI-E, and is an entirely different animal.

 

[buleyb]

Originally posted by: jliechty
Sun has multiple connectors for their proprietary graphics cards in a few of their workstations. I've heard rumors of a few rare Itanium workstations that were made with dual AGP slots (not sure if this system is real, but apparently the latest AGP spec allows for it in theory). I'm sure someone will make a motherboard with multiple PCI-Express x16 slots, but whether the public will be able to buy it or not is anyone's guess (e.g. 8-way Xeon boards are made, but try to order one from Newegg).

BTW, PCI-X is the latest revision of "normal" PCI 64 bit, that runs at up to 133MHz. PCI-Express is properly abbreviated PCI-E, and is an entirely different animal.

Yeah, I think he intended PCIe x16

 

[GoHAnSoN]

it is possilble, remember pciex16 can be backward compatible to x8 x4 x2 x1

 

[Peter]

Not really. You can't plug an x16 card into a narrower slot, but you can put a narrow card into a higher width slot. So if you want multiple graphics cards, you're going to need multiple x16 slots.

 

[SoCalBoomer]

Yes, sorry, I forgot the E. . .

I know it's Serial and point to point - which is why it should be possible to do, but then it's theoretically possible to have two AGP slots, but nobody does it.

But wouldn't it be NICE to have TWO 8GB-bandwidth graphics slots?

(and I haven't heard anyone making 8 bit vid cards. . .although that would be okay for secondary video. . .)

 

[KalTorak]

PCI Express is not a bus system, all connections are point-to-point. So unless some vendor comes up with a chipset that has multiple x16 links, we won't see that.

There's another way to do it; if you're willing to share bandwidth, you could use a PCI-E fanout switch (analogous to a PCI-to-PCI bridge) to hook multiple x16 devices to a single x16 interface...

 

[buleyb]

Originally posted by: KalTorak

PCI Express is not a bus system, all connections are point-to-point. So unless some vendor comes up with a chipset that has multiple x16 links, we won't see that.

There's another way to do it; if you're willing to share bandwidth, you could use a PCI-E fanout switch (analogous to a PCI-to-PCI bridge) to hook multiple x16 devices to a single x16 interface...

I see your point, but this is supporting Kal's argument. Your bridge chip would still have to support multiple x16 links, regardless where the shared bandwidth originates. So yes, people could do this, and its not unlikely, its unneeded right now.

The idea here is that its possible, but unlikely, because there isn't the demand for this yet. Give it few years, and there might be more high bandwidth slots as more and more data movement is needed.

 

[lowpost]

multiple PCI-E 16 slots... I'm thinking this would be high end workstation usage.

In a high end workstation you would use a high end video card, which usually have multiple display capabilites. So, why would you need more than one 16x slot? 16x would be more than capable of offering enough bandwidth to support a dual, triple or quadruple head card.

Multiple 16x slots would be feasable, but not practicle. I'm sure someone out there would have a use, but i doubt it would be mainstream to the point that it would be commercially available

 

[ProviaFan]

Originally posted by: lowpost
multiple PCI-E 16 slots... I'm thinking this would be high end workstation usage.

In a high end workstation you would use a high end video card, which usually have multiple display capabilites. So, why would you need more than one 16x slot? 16x would be more than capable of offering enough bandwidth to support a dual, triple or quadruple head card.

Multiple 16x slots would be feasable, but not practicle. I'm sure someone out there would have a use, but i doubt it would be mainstream to the point that it would be commercially available

Sorry, but there are a few problems with that scenario. First, the only triple head card out there (Parhelia) is rather limiting - all monitors run at the same res/refresh, and that's limited to a maximum of 1280x1024. Second, all quad head cards that I've seen, have next to nothing in the way of 3D acceleration, if any at all.

Having dual dual headed cards would be a great capability, and I'm sure that there are probably more people that would use it than you might think (how many workstations does Sun sell, and evidently there's enough of a demand from a small percentage of their customers that they have dual graphics card slots in some of their higher end systems). I'm sure it will be a while before that stuff comes around, though... just look at how long it's taken for dual DVI outputs to become mainstream (they haven't, yet).

 

[lowpost]

Multiple 16x slots would be feasable, but not practicle. I'm sure someone out there would have a use, but i doubt it would be mainstream to the point that it would be commercially available

I said multiple 16x slots would not be practicle but dual head cards would be. I use a dual head card. I don't argue that it has limitations, but it's a more practical option rather than dual agp or dual 16x slots.

 

[buleyb]

Forget graphics, there are other options for high bandwidth add-in cards...

 

[sao123]

Officially the AGP 3.0 standard provides documentation that dual AGP 8x slots are feasible.

I read an article on Toms Hardware earlier, that suggested dual PCI-e 16x slots would also be feasible however limited by only the bandwidth of the northbridge chipset.

The default configuration of the new intel motherboards include 1 pci-e 16x slot on the northbridge for video and 4 pci-e 1x slots attached to the southbridge for peripherals. There are no difference between the 1x and 16x versions except the number of lanes and theoretical bandwidth...therefore as long as the bandwidth is available on the northbridge...its possible.

 

[lexxmac]

It would be rather simple to implement once AMD releases the Hypertransport to PCI Express x16 Tunnel (the follow up to the 8151 AGP Tunnel). The same thing could have been done with AGP Graphics slots/cards, but the question is, will anyone bother to make a board that has more than one slot on it? I wouldn't get my hopes up on seeing one anytime soon...

 

[Peter]

It doesn't even have to be AMD ... there are other chip makers in the HyperTransport boat, e.g. ALi/ULi and PCI bridging expertx PLXtech. Since HyperTransport chipsets can be freely combined, a PCI Express tunnel chip from any maker could be bolted onto anyone else's chipset components.

 

[lexxmac]

I know, but that was the first to pop into my head. Heck, you could go as far as to use a Xilinx FPGA for a hypertransport device if you really wanted to. There's a whole list of things on the HT consortium's site.

 

[SoCalBoomer]

I also don't think that it would be only for workstations.

Several forums, including Ars Technica and several gaming ones that I frequent, show the use of multiple monitors gaining popularity - shoot, I use three both at work and at home.

But I DON'T want to split my primary vid card across both monitors while playing whatever game I'm in at the moment - I want all my GPU goodness sent to one monitor. . . that's why I want extra slots for extra cards, which I just can't do now. . .

 

[Pudgygiant]

The funny thing is, the more video cards advance, the less we need a connection of this speed, yet the more push there is from the community. I expect we'll see 512mb cards soon, so there'd have to be some MASSIVE textures to see more than a minimal performance gain from 8gbps.

 

[lexxmac]

The point is that now that the hardware can support extremely complex textures they will be used more. I hope to see complex graphics used in the actual GUI of an OS for some cool effects. I'd wish people woud find more ways than gaming to use graphics cards.

 

[lowpost]

I can't remember if I saw it on sourceforge, or freshmeat but a 3d OS is being developed. It reminds me a lot of the movie "Hackers" in that you navigate directories like a 1st person shooter.