PCIe 2.1 and 3.0

[theraque]

I'm just looking around for a mobo for a friend of mine in the market for a gaming rig. All new video cards are PCIe 2.1 compliant, but I have yet to find a mobo that actually has PCIe 2.1 onboard, they're all 2.0 and yes, I do realise that 2.1 will work on 2.0. I'm just interested to know if anyone's actually come across any mobo that specifically says it has 2.1 PCIe slots. I am aware that in the next 3 or so months we'll be getting PCIe 3.0 hit the market but that's 3 months at best since demo boards just were shown this month.

 

[marino.DV]

i also have a question regarding this topic: video cards that are running 3.0 can they be used on motherboards with 2.X let's say ?

 

[IntelEnthusiast]

PCI-e 3.0 will be backwards compatible to the earlier standards. So you can put a PCi-e 2.0 card into a PCi-e 1.1 slot and it will still work but at the limited speed the lower standard. http://en.wikipedia.org/wiki/PCI_Express

Christian Wood
Intel Enthusiast Team

 

[theraque]

I got a 2.1 Radeon 6850 on a 2.0 board and no probs.I realise all the versions are backwards compatible, I'm looking for a motherboard that contains said newer revisions to the spec. Any ideas where's I can get a 2.1 board?

 

[Stuka87]

PCI-e 3.0 will be backwards compatible to the earlier standards. So you can put a PCi-e 2.0 card into a PCi-e 1.1 slot and it will still work but at the limited speed the lower standard. http://en.wikipedia.org/wiki/PCI_Express

Christian Wood
Intel Enthusiast Team

This is entirely incorrect. The backwards compatibility between 2.x and 1.x is entirely OPTIONAL by the card maker. The truth is that very few 2.x cards will function in a 1.x slot. It is NOT a required part of the standard. There are quite a few other changes besides "speed" that separates the two.

I would not hold my breath on all 3.x cards working in 2.x slots.

 

[Epsilon-Zero]

The reason why you dont see any boards with an advertised 2.1 slot is that the difference between a 2.0 slot doesnt impact performance.

If I remember right it just added management, support, and troubleshooting systems; which actually wont be fully implemented until 3.0.

So basically dont worry about it, your 2.1 GPU will be running at full steam regardless if its on 2.0 or 2.1

@Stuka Im sure most of the 3.0 cards will work on 2.0 for the first 2 years of production, but it does remain to be seen. Hell, we may not even have cpus that can support it until next year if Intel cant get its act together.

 

[IntelEnthusiast]

This is entirely incorrect. The backwards compatibility between 2.x and 1.x is entirely OPTIONAL by the card maker. The truth is that very few 2.x cards will function in a 1.x slot. It is NOT a required part of the standard. There are quite a few other changes besides "speed" that separates the two.

I would not hold my breath on all 3.x cards working in 2.x slots.

OK thanks Stuka, I havent heard of one person that has a problem with the backwards compatibility on any PCI-e connect and there are no pci-e 3.0 cards yets to see but thank you for the correction.

Christian Wood
Intel Enthusiast Team

 

[Michael Meio]

IMO, PCI-e 3.0 will be stalled for a while.

In my experience, I've tested some PCI-e 2.0 and 2.1 GPUs on both PCI-e 1.x and 2.x, ran some tests, went back and forth and TBH, I can't say there is no difference, but I'm totally sure, no one can tell by experiencing but by numbers derived from such tests.

It all comes to bandwidth and other stuff but haven't crossed the bandwidth limit myself on a PCI-e 1.x... Maybe the way I use computers is far too ordinary and some purists surely disagree, but essentially, we could have lived without PCI-e 2.x and should survive for a long time steering clear from PCI-e 3.x.

I don't want to blame it all on economics but I guess we have to sit and wait to see who's gonna bet on this and win.

 

[VirtualLarry]

This is entirely incorrect.

No, it's not. Save for a few wierd motherboards with, say, Via chipsets, the vast majority of PCI-E 2.0-compatible cards work just fine in a PCI-E 1.1 mobo.

My P35 mobo with a PCI-E 1.1 x16 slot is living proof of that.