PCI Express 2.0

[Mattiethomas]

Alright, so I'm about to buy a motherboard for my new gaming PC. I had pretty much decided on one, while knowing it didn't support PCI-Express 2.0. But then I found one thats a little more money, but supports PCI-E 2.0. And I'm just wondering, is it worth it to spend more for the PCI-Express 2.0? Or should I ignore it and just get the motherboard with regular PCI-E 1.0? Just wondering how big a deal the two are and if it's worth it to spend more.

Thanks.

[butters]

PCIe 1.1 is the most common variety. I haven't seen any PCIe 2.0 graphics cards yet, and I'd be surprised if there are any for a while. I can't imagine anything using twice the bandwidth of PCIe 1.1 right now. There's many much more significant bottlenecks to overcome before worrying about video card bandwidth.

[Mattiethomas]

PCIe 1.1 is the most common variety. I haven't seen any PCIe 2.0 graphics cards yet, and I'd be surprised if there are any for a while. I can't imagine anything using twice the bandwidth of PCIe 1.1 right now. There's many much more significant bottlenecks to overcome before worrying about video card bandwidth.

My graphics card. It supports PCI-E 2.0 so I'm wondering if I should take advantage of that.

"PCI Express Base 2.0 specification doubles the interconnect bit rate from 2.5 GT/s to 5 GT/s in a seamless and compatible manner. The performance boost to 5 GT/s is by far the most important feature of the PCI Express 2.0 specifications. It effectively increases the aggregate bandwidth of a 16-lane link to approximately 16 GB/s. The higher bandwidth will allow product designers to implement narrower interconnect links to achieve high performance while reducing cost."

Seems like a decent improvement.

[Ex-Cyber]

There were some benchmarks done a while back with a couple graphics cards having some of their lanes blocked (taking advantage of PCIe's automatic negotiation process). I don't have it handy, but IIRC there was no major performance hit until they went below an x4 link, synthetic bandwidth tests notwithstanding.

I'd say that you should take a close look at the differences between the 1.1 and 2.0 motherboards, particularly in terms of CPU support if they're for Intel. You may be better off buying the 2.0-capable motherboard just to have a more recent chipset...

[butters]

They never even managed to take up all of the bandwidth of agp. There was never a point in having PCI express in the first place. The only people that get anything good out of it are motherboard making companies. If they had continued to make decent agp video cards, I would have never done my recent motherboard upgrade.

[Calavera]

If they had continued to make decent agp video cards, I would have never done my recent motherboard upgrade.

The X1950 pro is pretty decent.

[Ex-Cyber]

There was never a point in having PCI express in the first place. The only people that get anything good out of it are motherboard making companies.

That might be true if PCIe served only to replace AGP, but it also serves to replace PCI, which is arguably much more important in the long run. Yes, there are still PCI slots on current boards, just as there were still ISA slots when PCI was first introduced. I think you'll see PCI disappear from mainstream PCs faster than ISA did, too...

[butters]

There was never a point in having PCI express in the first place. The only people that get anything good out of it are motherboard making companies.

That might be true if PCIe served only to replace AGP, but it also serves to replace PCI, which is arguably much more important in the long run. Yes, there are still PCI slots on current boards, just as there were still ISA slots when PCI was first introduced. I think you'll see PCI disappear from mainstream PCs faster than ISA did, too...

Which just means that in another year or two I'll be needing a new motherboard because I won't be able to buy PCI devices anymore and only have one pcie x1 slot.

[APE]

There was never a point in having PCI express in the first place. The only people that get anything good out of it are motherboard making companies.

That might be true if PCIe served only to replace AGP, but it also serves to replace PCI, which is arguably much more important in the long run. Yes, there are still PCI slots on current boards, just as there were still ISA slots when PCI was first introduced. I think you'll see PCI disappear from mainstream PCs faster than ISA did, too...

Which just means that in another year or two I'll be needing a new motherboard because I won't be able to buy PCI devices anymore and only have one pcie x1 slot.

Nah, see you've already got the onboard essentials such as USB2 and ethernet. Sound card tech really hasn't changed that much (unless you beat off to X-Fi) and the majority of other add in cards such as video capture generally don't go obsolete that fast.

Now replacing cards might get tricky, but since I can find a multitude of cheap SB Live cards I don't think you'll have a problem.

[butters]

There was never a point in having PCI express in the first place. The only people that get anything good out of it are motherboard making companies.

That might be true if PCIe served only to replace AGP, but it also serves to replace PCI, which is arguably much more important in the long run. Yes, there are still PCI slots on current boards, just as there were still ISA slots when PCI was first introduced. I think you'll see PCI disappear from mainstream PCs faster than ISA did, too...

Which just means that in another year or two I'll be needing a new motherboard because I won't be able to buy PCI devices anymore and only have one pcie x1 slot.

Nah, see you've already got the onboard essentials such as USB2 and ethernet. Sound card tech really hasn't changed that much (unless you beat off to X-Fi) and the majority of other add in cards such as video capture generally don't go obsolete that fast.

Now replacing cards might get tricky, but since I can find a multitude of cheap SB Live cards I don't think you'll have a problem.

An x1 slot still isn't all that fast at that. At 250 MB/sec it couldn't handle a 10 gbps network card, which I can see becoming common once solid state drives become more practical and fast.

[Ex-Cyber]

An x1 slot still isn't all that fast at that. At 250 MB/sec it couldn't handle a 10 gbps network card

That's why PCIe 10Gbps network cards are x4 cards, which will rather conveniently also work in an x8 or x16 slot, which you ought to be willing to dedicate if you've got the traffic to justify a 10Gbps NIC in the first place. Your other option would be to buy a motherboard with a 64-bit/133MHz PCI-X bus and dedicate that bus to the NIC.

[butters]

An x1 slot still isn't all that fast at that. At 250 MB/sec it couldn't handle a 10 gbps network card

That's why PCIe 10Gbps network cards are x4 cards, which will rather conveniently also work in an x8 or x16 slot, which you ought to be willing to dedicate if you've got the traffic to justify a 10Gbps NIC in the first place. Your other option would be to buy a motherboard with a 64-bit/133MHz PCI-X bus and dedicate that bus to the NIC.

I was simply trying to think of something that would actually need the speed of PCIe, and a fast network card is all that I can think of. The reason I bought up x1 is because most cheaper motherboards that I have seen have one x16 slot and maybe a couple of x1 slots.

[Ex-Cyber]

An x1 slot still isn't all that fast at that. At 250 MB/sec it couldn't handle a 10 gbps network card

That's why PCIe 10Gbps network cards are x4 cards, which will rather conveniently also work in an x8 or x16 slot, which you ought to be willing to dedicate if you've got the traffic to justify a 10Gbps NIC in the first place. Your other option would be to buy a motherboard with a 64-bit/133MHz PCI-X bus and dedicate that bus to the NIC.

I was simply trying to think of something that would actually need the speed of PCIe, and a fast network card is all that I can think of. The reason I bought up x1 is because most cheaper motherboards that I have seen have one x16 slot and maybe a couple of x1 slots.

I think you're looking at it from the wrong direction. PCIe's development and adoption are justified by PCI's drawbacks in the face of current technology. PCI's capacity can barely keep up with modern interfaces that are already widely adopted, such as gigabit Ethernet, Hi-Speed USB, and Firewire 400/800. What's more, with current technology, the manufacturing cost of simpler chips (i.e. nearly anything besides CPUs, GPUs, and memory) is determined almost entirely by the number of I/O pins they need; PCIe's scalable serial design drastically reduces the number of I/O pins required compared to PCI. PCIe's speed is justified by the fact that it can be practically accomplished with current mainstream manufacturing and design technology - since it's a big hassle for everybody to switch to a new standard, they may as well peg the new standard to the state of the art rather than try to eke out a few more years of sort-of-compatibility by mainstreaming something like PCI-X (which I'm pretty sure would have been more expensive anyway).

That said, I do think it's a little odd that x16 was the standard adopted for graphics cards. The main things that come to mind are power limits and fast access to host memory (e.g. for the "TurboCache"/"HyperMemory" scheme), but heck if I know...