Extreme4 Gen3 2 - pcie 3.0 x16 quick question

[clairmel1]

Hi, quick question... I was planning on buying the Extreme4 and pairing it with a 560ti for initial startup ( with a second 560ti to come later )

I see what looks like there will be 2 x PCIe 3.0 x16 Slots available when used with the new ivy bridge cpu.

Is that correct? Does that mean that with the new Ivy Bridge I can SLI two cards running at 3.0 x16 speeds?

And at PCIe 2.0 there is just one x16 slot available?

Not worried about the combined output just the configuration.

Thanks.

 

[jaquith]

No, the IB and SB are both 16 lanes for GPU(s) in total only; so (1) GPU x16, (2) GPU's x8/x8. The GTX 560 won't saturate an x8 PCIe 2.x slot. This 16 PCIe lanes is either PCIe 2.x or PCIe 3.x, and in order to have PCIe 3.x everything MUST be PCIe 3.x: CPU IB (Ivy Bridge), MOBO 2nd slot with PCIe 3.x switch, and GPU with PCIe 3.x interface; the GTX 560 Ti is PCIe 2.1.

Also, it will be a very long time before PCIe 3.0 does anything, and probably years. Here's a PCIe 3.0 vs PCIe 2.0 test on the new SB-E X79 and a PCIe 3.0 GPU (PCIe 3.0 'clean'). PCIe 2.x 500 MB/s (5 GT/s) per lane and PCIe 3.x 1 GB/s (8 GT/s) per lane; PCIe 3.x is backwards compatible with PCIe 2.x, but as stated in order to run PCIe 3.x everything has to be PCIe 3.x.

 

[xtreme5]

you are able to fit any gpu on pci 3.0 cause it is backward compatible to pci 2.0 or 2.1 suppose if you were using two gtx 570 in sli then x16 becomes half for both card like x8/x8 which is totally same as x16 or if you were using one card then it's x16.

 

[clairmel1]

No, the IB and SB are both 16 lanes for GPU(s) in total only; so (1) GPU x16, (2) GPU's x8/x8. The GTX 560 won't saturate an x8 PCIe 2.x slot. This 16 PCIe lanes is either PCIe 2.x or PCIe 3.x, and in order to have PCIe 3.x everything MUST be PCIe 3.x: CPU IB (Ivy Bridge), MOBO 2nd slot with PCIe 3.x switch, and GPU with PCIe 3.x interface; the GTX 560 Ti is PCIe 2.1.

Also, it will be a very long time before PCIe 3.0 does anything, and probably years. Here's a PCIe 3.0 vs PCIe 2.0 test on the new SB-E X79 and a PCIe 3.0 GPU (PCIe 3.0 'clean'). PCIe 2.x 500 MB/s (5 GT/s) per lane and PCIe 3.x 1 GB/s (8 GT/s) per lane; PCIe 3.x is backwards compatible with PCIe 2.x, but as stated in order to run PCIe 3.x everything has to be PCIe 3.x.

http://images.hardwarecanucks.com/image//skymtl/GPU/HD7970/HD7970-69.jpg
http://images.hardwarecanucks.com/image//skymtl/GPU/HD7970/HD7970-68.jpg

Ok, in order to not make this more confusing than need be... lets start with the basics and see if I'm following you:
I understand that in order to have PCIe 3.x everything has to be PCIe compliant -i.e. the mobo, cpu, gpu, etc...
Correct?


The reason I got into all this was because I saw that the
Extreme4 had 2 x PCIe 3.0 x16 Slots and the
Extreme7 had 1x PCIe 3.0 x16 Slot

That seemed backwards to me. Why would the Extreme4 have two 3.0 slots and Extreme7 only one?

And on the extreme7 gen3 it's possible to do PCIe 2.x -x16/x16 SLI setup due to the NF-200 chip.
Correct?
But what happens when you move everything to PCIe 3.0 on the Extreme7? Do you only have one 3.0 x16 lane and...?the other two at PCIe 2.x x8/x8 ? Like can you still have 32 lanes with 3.0 capabilities?

And as for the Extreme4 - is it just strictly an x16/x8/x8 board at either PCIe 2.x or 3.x? ( and not x16/x16)

Thanks for your help. I'm just trying to better understand the architecture.
And since I plan on getting the Extreme 4 and want to know if I'll have x16/x16 capabilities or not.

Thanks.

 

[jaquith]

I understand that in order to have PCIe 3.x everything has to be PCIe compliant -i.e. the mobo, cpu, gpu, etc...
Correct?

Correct.

The reason I got into all this was because I saw that the
Extreme4 had 2 x PCIe 3.0 x16 Slots and the
Extreme7 had 1x PCIe 3.0 x16 Slot

That seemed backwards to me. Why would the Extreme4 have two 3.0 slots and Extreme7 only one?

And on the extreme7 gen3 it's possible to do PCIe 2.x -x16/x16 SLI setup due to the NF-200 chip.
Correct?

Depends on which ASRock Extreme4 or Extreme7, there's the Intel P67/Z68 LGA 1155 and the X79 LGA 2011; my guess is that you confused them. The X79 SB-E does have 32-lanes of PCIe 3.x, but the P67/Z68 only has 16-lanes of PCIe 2.x or 3.x (GEN3). Example, the Z68 Extreme7 Gen3 offers the NF200 chipset that in addition to the Native SB 16 lanes adds effective 16 more, but ultimately is still funneled into the Native 16 lanes of the SB, or x16/x8/x8 or in some cases, need to check your manual, x16/x16. However, the NF200 like the older X58 chipset adds some latency. The Z68 Extreme4 Gen3 is x16 or x8/x8 and Native to the SB.

Problem, the GTX 560 is limited to 2-WAY SLI and cannot saturate an x8 PCIe 2.x so if it were 'me' I prefer the Native x8/x8. Here's a decent article X58 vs P67 vs NF200 -> http://www.tomshardware.com/reviews/p67-gaming-3-way-sli-three-card-crossfire,2910.html

However, if you ever plan on getting GTX 600 series in 3-WAY SLI then you'd need the NF200 on any LGA 1155 MOBO.

But what happens when you move everything to PCIe 3.0 on the Extreme7? Do you only have one 3.0 x16 lane and...?the other two at PCIe 2.x x8/x8 ? Like can you still have 32 lanes with 3.0 capabilities?

And as for the Extreme4 - is it just strictly an x16/x8/x8 board at either PCIe 2.x or 3.x? ( and not x16/x16)

Explained some more. The ASRock Extreme7 is x16/x8/x8 PCIe 2.x or PCIe 3.x (CPU/GPU dependent; lowest wins aka all or non 2.x vs 3.x), and the ASRock Extreme4 x8/x8 PCIe 2.x or PCIe 3.x same dependencies.

Here's the idea with PCIe 2.x vs 3.x, besides whats been said, if I took an IB and PCIe 3.x compliant GPU then on the primary Native slot it will run PCIe 3.x GEN3 or not where there's a direct PCIe to CPU link, but a PCIe 3.x Switch is required for all the other PCIe slots to be PCIe 3.x. So the difference is in the Switch.

Further, even the current PCIe 3.x clean, on an X79 you can get it today, there's been no improvement. This is no surprise because the current top of the line GPU's cannot touch the x8 PCIe 2.x lanes.

Again, the only reason to consider a MOBO LGA 1155 with an NF200 is to have 3-WAY SLI - period.

 

[clairmel1]

Very nice way to sum it up jaquith. The last line brought it all together. I should have specified it was a Z68 board up front -Noob posting mistake lol. http://img.tomshardware.com/forum/uk/icones/smilies/sarcastic.gif


I've read here and there on the forums that current line of GPU's don't saturate the x8 PCIe 2.x lanes but it's hard to believe in some weird way.

So generally speaking in terms of a GPU's ability to saturate lanes on an 1155 Z68 board....
Would 2 - GTX 560's in SLI saturate an x8 PCIe 2.x lane BUT not enough to fill 16 lanes.

Just curious. I won't bug you with any more questions. It looks like I'll be just fine with the Z68 Extreme4 board. Really appreciate your time. Thanks.

 

[jaquith]

Good point and best I can tell no one knows for certain how many lanes of PCIe 2.x are actually being saturated. A lot of it has to do, obviously with how much data is being pushed, and for the most part the closest answer is both resolution and details of the particular game. I say particular game because some games on 5900 x 1080 have no vRAM bottleneck while others are horribly crippled unless the GPU's have 2GB~3GB of vRAM.

The Q "GTX 560's in SLI saturate an x8 PCIe 2.x lane BUT not enough to fill 16 lanes." suggests x4 PCIe 2.x lanes per GPU. The good news is you'll never have to worry about it because nVidia will never provide a BIOS Key to any MOBO with less than x8 PCIe 2.x per GPU. But in theory yes a GTX 560 can saturate PCIe 2.x x4 lanes.

Here's a great PCIe scaling article -> http://www.techpowerup.com/reviews/NVIDIA/GTX_480_PCI-Express_Scaling/1.html you'll see some games that are unaffected by x4 vs x8 vs x16 while some do show the difference. Therefore, my feeling is no GPU out there saturates x8 PCIe 2.x but many do saturate x4 PCIe 2.x so the best answer is somewhere in-between. Further a PCIe 2.x x16 has the same bandwidth of PCIe 3.x x8.

BTW - I often wonder about the 'taping' method...

 

[clairmel1]

Best answer selected by clairmel1.

 

[nikorr]

This topic has been closed by Nikorr