Is PCI-e fundamentally flawed?

[Kef9]

I was thinking about pci-e and thought about the time when we will need 32x lanes. I know this is a long way off as we only really utilise around 8 lanes of bandwidth at the moment but think about this.

In its current form the length of the pci-e slot is an indicator of the bandwith provided by the lane. Now correct me if im wrong but a 32x lane would be nearly twice as long as a 16x lane and would probably fill the entire length of the motherboard.

Looking at the jump from AGP v1, v2 and v3 this will happen in around 2-3 years. Is a 32x long lane feasible for a graphics card (never mind 2 for sli) and what about 64x lanes when required?

I personally cant see the current pci-e architecture lasting anywhere near as long as AGP. They surely must have to change the bus speed of the lanes to get the gains required.

What do you guys think?

[nvening]

Well mabe and they will do that, i dont get you?

[kempez]

Nvidia have already launched SLi 16 with 32lanes so I don't see why it won't last as long as AGP.

The current gen of cards don't even take up the 8x bandwidth of PCI-E, so why would they need 32 x right now?

[arthurleung]

I don't think there is a need for 32x lanes.

If you want higher bandwidth, increase the PCIe clock.
Wanna double the bandwidth? go from 100Mhz to 200Mhz

If you really want 32 lanes? Just increase the density of the pins (2 pins in the position of 1. Attaching an old card will have that 2 pins sharing the same signal (or disable one of the pair)
, attaching a new card will have the 2 pins transferring the same signal.

IMO they should make a GPU socket on the motherboard, so you can mount a CPU heatsink on it, and any amount of gddr3ram you needed

[nvening]

2 motherboards, with physix card and the ai one if it happens! and it would be shaped like a banana!!!!!!!!!

[Jonny]

IMO they should make a GPU socket on the motherboard, so you can mount a CPU heatsink on it, and any amount of gddr3ram you needed

Good Plan! Seriously, why do they not do that?

[Kef9]

Nvidia have already launched SLi 16 with 32lanes so I don't see why it won't last as long as AGP.

The current gen of cards don't even take up the 8x bandwidth of PCI-E, so why would they need 32 x right now?

So why did we need pci-e when AGP was fine?

Basically we will need 32x sooner than you think.

Also the SLi with 32 lanes is split in two (2*16). what about when you have 2 No 32x lanes?

[Kef9]

If this is the case, from a mobo manufacturers point of view its not flawed, as everyone will still go out and buy the 'new' standards.

Of course!

All I am really trying to say is that pci-e may not be around for that long in its current form.

[Mike Fishcake]

Hiya Kef!

You seem to be making a lot of assumptions with not much base behind them other than guesswork. Do you have any technical information behind this or is it just a gut feeling?

"So why did we need pci-e when AGP was fine?"

I can't see what point you're making. Are you directly asking the question, or is it a rhetorical question? Either way, it doesn't correspond with the rest of your post.

[Butcher]

Well I think the next step is to go to faster lanes, not more of them. With each lane only going to a single end point it may even be possible to have different cards running at different speeds as well.
PCI-e even in it's 8x incarnation is better than AGP as it's much less latent, when talking to a GPU over it, that's a good thing.

[Kef9]

Hiya Kef!

You seem to be making a lot of assumptions with not much base behind them other than guesswork. Do you have any technical information behind this or is it just a gut feeling?

"So why did we need pci-e when AGP was fine?"

I can't see what point you're making. Are you directly asking the question, or is it a rhetorical question? Either way, it doesn't correspond with the rest of your post.

AGP does not limit the performance of current graphics cards so why did we move to pci-e.

The reson is because mobo makers wanted to make money. What im saying is that pci-e in its current format may not be around for that long.

[Xaneden]

You have to remember that different types of graphics cards in the future may provide different arrays of connections. In that case, having generic output ports inbuilt into the motherboard (which connect to the GPU socket) may not be a viable solution

[mike_w]

The reson is because mobo makers wanted to make money. What im saying is that pci-e in its current format may not be around for that long.

Don't forget about the other cards that can go in a PCI Express slot i.e. the ones for the 1x slots. I think it would be a while before we see sound cards needing the bandwidth of a 16x slot.

[BUFF]

So why did we need pci-e when AGP was fine?

PCI-E wasn't developed just to replace AGP - the PCI bus is limited to 133Mb/s & we've been seeing cases of it getting saturated for a couple of years.
A single lane PCI-E 1x lane is capable of transmitting 2.5Gbps in each direction, simultaneously.

[oralpain]

That and standard AGP/PCI slots provided a good deal less power than a PCI-E slot.

PCI-E is also replacing PCI-X eventually. There have been PCI-E 8x raid controlers out for a while.

I don't think PCI-E 32x will ever be used for video cards.

[kalniel]

If we need to move to 32x lanes then the obvious solution would be to simply pair two 16x lanes side by side, then either have double slot cards or ones with a riser at the bottom giving two rows of connections.

But likely we won't have pci-e32 at all - by the time it's needed another technology will take it's place - perhaps something low latency and whose controller is on the CPU