Difference between PCI-e 2.0 and 3.0?

[clubber_lang]

On a lot of these new boards coming out I see they are all jumping up from 2.0 to 3.0.....is there a benefit for this right now? Will the Gpu's we are using now or any time soon be able to take advantage of the 3.0 express lane?

I'm still learning this stuff , so I have no idea really how it all works. Just going by what I have read here and other places , that say 2.0 isn't even close to being fully used yet.

What are your thoughts on this and if you have the time , can someone explain to me the difference between the two in Laymen's terms?

[The Jesus]

This is from our very own Callsign_Vega:



There is a big difference when using SLI/CF on the newer cards apparently. Early tests indicated otherwise, but now we're starting to see that's not the case.

The main difference between 2.0 and 3.0 is the bandwidth available to the cards, thus allowing greater amounts of data (to render) to be transferred to them and reported back.

[clubber_lang]

Thanks for the graph TJ.

I'm having a hard time trying to figure it out exactly as I don't know what the different color bars actually mean. It does look like the 3.0 on the right is faster in most cases.

And so it has been proven that the PCI-e 3.0 works even better on Cfx and Sli than what it would on a single card?

So lets take something like a P67 or Z68 board with a set of two cards......in theory a Z77 should perform better using the same cards and it everything is set to the same specs? I knew 3.0 was supposed to be better.....I just didn't know by how much.

[koc]

I was thought that , the PCI-E 3.0 shine at higher resolution 2560 x 1600 and above , but looks like even at HD there are a different .

[UNTAMED]

from Wik
PCIe 2.0 delivers 5 GT/s, but uses an 8b/10b encoding scheme that results in a 20 percent ((10-8)/10) overhead on the raw bit rate. PCIe 3.0 removes the requirement for 8b/10b encoding, and instead uses a technique called "scrambling" that applies a known binary polynomial to a data stream in a feedback topology. Because the scrambling polynomial is known, the data can be recovered by running it through a feedback topology using the inverse polynomial.[21] and also uses a 128b/130b encoding scheme, reducing the overhead to approximately 1.5% ((130-128)/130), as opposed to the 20% overhead of 8b/10b encoding used by PCIe 2.0. PCIe 3.0's 8 GT/s bit rate effectively delivers double PCIe 2.0 bandwidth. PCI-SIG expects the PCIe 3.0 specifications to undergo rigorous technical vetting and validation before being released to the industry. This process, which was followed in the development of prior generations of the PCIe Base and various form factor specifications, includes the corroboration of the final electrical parameters with data derived from test silicon and other simulations conducted by multiple members of the PCI-SIG.

-JUST REMEMBER
-mb to sb = x16 lanes of 2.0 -even running pci-e 3.0 cards\z77 mb.

-mb to ivyB = x16 of 3.0 so double the bandwidth regards less how the mb divides up the lanes per cards

-also ib will be the first fully rated pci-e 3.0 chip per intel. not sure why ,did see a bench of data showing a x79 chips at only 75% return data speed cpu to gpu of the pci-e spec. for 3.0 ,gpu to cpu was 100%.not a big deal but still not full pci-e 3.0 speeds

-so this year 2.0 is fine, but in the future 2 x gtx 780's might have a bottle neck at x8x8 pci-e 2.0 at high res.

-just my opinion but this is why I'm waiting for ivyB for the 3.0 ,not sure what cards I might be running in 2013.
-if ivyB is a dud as some expect, I might go x79\3820

[PatRaceTin]

what about single card user ?

[Ket]

For single card users mostly PCI-E 3.0 won't make a difference unless you are using a real top end card in which case its been shown modern top end cards do start to get limited on a PCI-E 2.0 bus. However this limiting isn't too bad, at least not in any tests I've seen yet.