PCIE Lane Population Rules

Re:PCIE Lane Population Rules (Aggressor Prime)

Thu, 19 Jan 2012 03:16:26 GMT

lehpron

Looking at the X79 FTW visual guide page 2:

Slot 1: x8/x16 (switch)
Slot 2:   x1 (perm)
Slot 3:   x8 (perm)
Slot 4:   x4 (perm)
Slot 5:   x8/x16 (switch)
Slot 6:   x8 (perm)

I wonder if it is possible that slots 3 & 6 share bandwidth with 1 & 5 such that if they are populated, then they switch, thus 3-way SLI + PhysX as x8+x8+x8+x8. But JacobF didn't cover 2-way + PhysX, so it should be possible using slot 4 for PhysX and maintain dual x16's.

Looking at the X79 Classified visual guide page 2:

Slot 1: x8/x16 (switch)
Slot 2: x1 (perm), same as FTW
Slot 3: x8 (perm), same as FTW
Slot 4: x4 (perm), same as FTW
Slot 5: x8/x16 (switch)
Slot 6: x8/x16 (switch)

JacobF says it 8-8-16 for 3-way SLi, so similar to FTW, then 1 is affected by 3 and 6 is affected by 5. Except if nothing in 3 or 6, 1 and 5 remains x16.   If wanting 2-way SLi, must use slot 1 & 5. Any other add-in PCIe like PhysX or audio must go in 2 or 4, otherwise you loose dual x16.

Looking at the X79 regular SLI visual guide page 2:

Slot 1: x8/x16 (switch)
Slot 2: nothing
Slot 3: x8/x16 (switch)
Slot 4: x1 (perm)
Slot 5: x8 (perm)
Slot 6: x1 (perm)

JacobF says up top that 3-way SLI will enabled 16-8-8, so why is the top slot 1 allowed to switch, shouldn't it be permanent x16? Clearly a card occupying slot 5 affects slot 3. So unlike FTW, 2-way + PhysX will loose dual x16's.

daleorama78

You completely missed the point........Every other board manufacturer used 32 also for the X58. Every other board manufacturer is using 40 lanes for the X79. Your point is moot.
I had a lot of points, don't generalize. Quite frankly, when PCIe 3.0 gets certified, there is reason to worry about that because each x8 3.0 will function like x16 2.0. Like I said, it will be several years before 3.0 spec graphics cards come to succeed 8 lanes, by then X79 will be dethoned.

A correction on your Classified chart. I didn't get it myself before, but I do now, why both slots 4 and 5 are labeled PCIE_X16/X8. The type of switch between these slots works both ways. If you look at the 2-way SLI connector from the pictures, it looks longer than the 3-way SLI connector and as long as the 4-way SLI connector, making me believe that you use your very first and very last slots for 2-way SLI, a rather smart design for OCing. In this case, your lane distribution would be: X16 (GPU), X1, X0, X4, X0, X16 (GPU). For 3-way SLI, you would use your top most PCIe X16 slots leading to a lane distribution of: X8 (GPU), X1, X8 (GPU), X4, X16 (GPU), X0. For 4-way SLI, you would use all your PCIe X16 slots that are evenly spaced apart leading to a lane distribution of: X8 (GPU), X1, X8 (GPU), X4, X8 (GPU), X8 (GPU). Therefore, if you want to load in a PhysX card or any other card that uses more than 1 lane, it is best to use that X4 slot (physically X16), as it is on its own, dedicated lane. Remember, PhysX is not needy when it comes to PCIe lanes, so even a PCIe 2.0 X4 connection is good enough. Of course, this being a PCIe 3.0 X4 slot, newer cards will see a slight benefit for PhysX. For cards that only require one lane, use the X1 slot. Another note, all the red slots are of course PCIe 3.0, while the black slot is PCIe 2.0 (from the chipset).

And yes, it looks like eVGA could have used that extra X4 bandwidth to bump up 3-way and 4-way SLI. My guess is, it was supposed to be used for SAS until Intel cancelled that for X79. Perhaps they never got around to rewiring the board, in which case, don't expect a BIOS update to fix that. Not really a big deal for gamers considering how fast PCIe 3.0 is, although this may be quite annoying for other people who need the bandwidth.

Re:PCIE Lane Population Rules (ximius)

Thu, 19 Jan 2012 01:24:52 GMT

lradunovic

N200 chip rules, think N200 chip should go to x79 platform reason is Intel acting stupid and not providing enough PCIe lines.

Im pretty sure X79 has not only MORE PCIE lanes available, but also double the bandwidth with PCIE 3.0. So how is Intel "acting stupid" exactly?

Re:PCIE Lane Population Rules (Rgallant)

Wed, 18 Jan 2012 15:09:58 GMT

lradunovic

N200 chip rules, think N200 chip should go to x79 platform reason is Intel acting stupid and not providing enough PCIe lines.

er they don't do pci-e 3.0

Re:PCIE Lane Population Rules (lradunovic)

Wed, 18 Jan 2012 06:20:53 GMT

N200 chip rules, think N200 chip should go to x79 platform reason is Intel acting stupid and not providing enough PCIe lines.

Re:PCIE Lane Population Rules (nateman_doo)

Wed, 18 Jan 2012 06:13:02 GMT

*ahem* anyone wanna buy an X58 with 3 16X... with the NF200?

Re:PCIE Lane Population Rules (Rgallant)

Sun, 01 Jan 2012 15:31:33 GMT

-see post 24 of 37

Re:PCIE Lane Population Rules (_REAPER_)

Sun, 01 Jan 2012 00:00:56 GMT

I have a stupid question, I have 2 gpus and the new X79 Classified mobo what PCI SLOTs do I have to put them in for both to remail at 16X

Re:PCIE Lane Population Rules (eduncan911)

Tue, 27 Dec 2011 05:47:05 GMT

FCooley

Thanks for the clarification. Even if it did support X16, X16, X8 I would plug in a X1 sound card anyway. I don't think for gaming its gonna matter much. I found an article on Hardocp where they compared SLI 480's with X16 & X8 and only really high res 5760x1200 had an impact in performance.
I'm still going to go EVGA for an x79 build. I'd hate to have to deal with any other Mainboard manufacturer's support, and a possible RMA would be a nighmare.

And I game at 6000x1080, yep it affects me directly. And to think, they were using stock 480s. My 580s hydros are overclocked 33%. Btw there are two non-direct-PCI-E slots you can use for the 1x sound card (on the FTW board, the SLi board 1). Those do not affect the x16-x16 performance of using only two cards. E.g. place your two cards separately on the two furthest slots, and put the 1x sound card into a slot between them marked as 1x or 4x.

This was not documented and I've now decided to return my EVGA X79 FTW. Problem is, they are trying to charge me a restocking fee for their mistake (all pieces, even the mobo, is unopened - I only opened the box to verify it had the LGA2011 protector as those without it are not covered under warranty - now, I am being punished for inspecting it to make sure I had warranty on the product).

This is turning into a real nightmare. $60 restocking fee, for inspecting if the board was covered under their warranty?

Re:PCIE Lane Population Rules (FCooley)

Mon, 26 Dec 2011 21:17:58 GMT

Thanks for the clarification. Even if it did support X16, X16, X8 I would plug in a X1 sound card anyway. I don't think for gaming its gonna matter much. I found an article on Hardocp where they compared SLI 480's with X16 & X8 and only really high res 5760x1200 had an impact in performance.
I'm still going to go EVGA for an x79 build. I'd hate to have to deal with any other Mainboard manufacturer's support, and a possible RMA would be a nighmare.

Re:PCIE Lane Population Rules (eduncan911)

Mon, 26 Dec 2011 16:40:21 GMT

FCooley

What about 2-way SLI plus Physx? I am planning an X79 upgrade and want to use EVGA mainboard. I want 2x580 SLI and a GTX 285 for physx. Can I use the GTX 285 for physx and keep my 2 580's @ x16?

Thanks

And there, my friend, is exactly the issue. The answer is no. If you run just two cards, you 'll get x16. But if you stick anything into the other two slots, say a card for PhysX, your two cards will run in x16-x8, and the PhysX card will be x8. Absolutely no different than the X58 platform, and actually goes against the specifications of the X79 platform itself.

Re:PCIE Lane Population Rules (FCooley)

Sun, 25 Dec 2011 13:43:25 GMT

What about 2-way SLI plus Physx? I am planning an X79 upgrade and want to use EVGA mainboard. I want 2x580 SLI and a GTX 285 for physx. Can I use the GTX 285 for physx and keep my 2 580's @ x16?

Thanks

Re:PCIE Lane Population Rules (linuxrouter)

Tue, 20 Dec 2011 19:18:04 GMT

One of the distributed computing projects I run is Einstein@Home. I measured a significant loss in performance by moving the card from a 16x to 8x slot which I've tested multiple times. I measured similar loss in both Linux and Windows operating systems. Here are the results I had with this particular application using the Linux GPU application:

16x: 2131 seconds
8x: 2984 seconds

In the case of the 16x slot, the tasks completed significantly faster. Multiple others users have reported similar performance loss so these results have been confirmed. Not all CUDA apps are affected but I have seen performance loss by switching to an 8x slot with some applications particularly those applications which have a greater dependence on the CPU.

If I was only gaming, I would not worry about the PCI-E lane allocation but I use my GPUs for other purposes as well. Both CUDA and OpenCL are becoming increasingly popular as time goes on and as a result users will become more dependant on additional PCI-E lanes that the latest processors can be provide.

Re:PCIE Lane Population Rules (lehpron)

Tue, 20 Dec 2011 17:55:39 GMT

I found an interesting tid-bit regarding an Asus X79, but the claim in the block diagram was from Intel's website regarding their own boards, so it is general. Notice how one of the PCIe 3.0 lanes is being used for two additional USB 3.0 ports...what's the EVGA layout look like? We can't assume all the lanes are used just for PCIe anymore.

eduncan911

Your generalization that only 2% is lost is incorrect with CUDA applications, and you are even quoting older 480 hardware opposed to 580s running at 975 Mhz (which, mine are).

If I Google "CUDA PCIe scaling analisys" guess what I get? Nothing relevant, why? Not enough demand, not enough people using CUDA to their limit question PCIe scaling to have a reviewer do the analysis for all to see. Most people are concerned with gaming PCIe scaling, hence if I search for that I get many more hits. My 2% "generalization" was an average and only based on gaming and benchmarks since I don't use CUDA, thus if I talked about it I'd be ignorant, wouldn't I?

Per link above, the loss at 2560x1600 for GTX480 is even lower, at 1% at x8 and 5% at x4, it isn't linear. So your equivalent loss at x8 isn't much just because your fill rates are 40% higher due to more cores running faster-- of course you're not playing a game with it.

That said, how different is the rendering computation of a massive resolution with high-details from the back-and-forth computation of using the graphics processor for parallel applications? I feel whether the output is with multiple frames per second (like a game), a single-frame render (CAD model) or a massive text file doesn't make a difference with respect to the processing power and communication accross the PCIe slot. I get the impression from your reactions that your specific CUDA uses need more bandwidth (i.e. more lanes) than a game at some extreme setting. Are you too impatient to show/inform me so I can better understand the situation as you see it?

Maybe you can make more sense of this FAH analysis. Tried looking into this, but nothing exceptional about PCIe scaling performance. Found a game-oriented link thinking GPU-intensive has more in common with CUDA uses than CPU-intensive such that 3-way SLI GTX580's at 2560x1600 don't perform much differently X79 or P67 so the lane losses are equally minimal with a GTX480-- but of course it's a game thus you can ignore that too.

Here's a thought: If you change your board configuration from x16 to x8 to x4 to x1 for all four of your HC's, how does your CUDA performance change? I suspect x4 on down may show a sharper drop, but I doubt the difference between x16 and x8 is 40% to account for the difference between a stock GTX480 and your GTX580 HC's. But if you are worried about there being any difference at all, then there is nothing I can do to calm you.

Re:PCIE Lane Population Rules (eduncan911)

Tue, 20 Dec 2011 14:53:49 GMT

I am not one fortit-for-tats, but dude seriously?

Are you even reading our posts? Your generalization that only 2% is lost is incorrect with CUDA applications, and you are even quoting older 480 hardware opposed to 580s running at 975 Mhz (which, mine are).

You know what, I am not even going to to correct you on your other points and re-state what has already been stated multiple times, which you are ignoring. Got other things to do, thank you.

Re:PCIE Lane Population Rules (lehpron)

Tue, 20 Dec 2011 14:48:33 GMT

eduncan911

To run at PCI 3.0, you will need a PCI 3.0 graphics card. So your point only applies to not one, but two future pieces of hardware and software releases.

So yes, there is a reason to worry - for those of us that have invested over $2200 in our 580s Hydros that are only, and will remain only, PCI 2.0 cards. If a PCI 2.0 card is inserted into a PCI 3.0 slot, it will run at PCI 2.0 only. So your "points" are muted unless addressing PCI 3.0 cards, which there are none ATM.

If the way I interpreted 2.0 x16 = 3.0 x8 was wrong in the sense that each slot would operate at x16 rather than the 8 lanes implied, then I apologize. That said, did you expected older hardware to operate within a new standard that didn't exist at its creation? That hasn't happened before. USB 2.0 drives don't take advantage of USB 3.0 bandwidth. I can't expect an SATA 3Gbps drive to run faster when plugged into an SATA 6Gbps socket. Even PCIe 1.1 cards didn't operate 2.0 in a 2.0 slot.

It has been shown that even a GTX480 barely looses 2% on average in a 2.0 x8 slot, meaning even if you plug your $2200 worth of cards in all x8 slots and they operate at 2.0, you don't miss out much -- especially considering better boards with LGA2011 socket don't exist so everyone with Quad GTX580's will experience the same performance.

You're definitely not getting four x16 because there aren't 64 lanes in the PCIe controller. So unless you want to go back to an X58 with nF200's, you can't yet make the jump to X79 until nVidia decides to make a 3.0 revision, let's call it a "nF300 chipset" just to enabled four 2.0 x16's when you plug your cards in.

Re:PCIE Lane Population Rules (linuxrouter)

Tue, 20 Dec 2011 09:57:54 GMT

I haven't been the biggest fan of Asus in the past but their Rampage IV board is looking decent. The top most slot is lined up with the top expansion slot of the case which is good for older cases with 7-expansion slots while still being able to support quad-SLI in a case with 8 expansion slots. The board is 12x10.7" in dimensions and should fit in an EATX case. In addition, the primary four slots are able to operate at x16/x16, x16/x8/x16, or x16/x8/x8/x8.

Re:PCIE Lane Population Rules (eduncan911)

Tue, 20 Dec 2011 09:33:15 GMT

Jacob just responded:

www.evga.com/forums/tm.aspx?high=&m=1377829&mpage=1#1377956

"It cannot be changed via BIOS [update]."

Re:PCIE Lane Population Rules (eduncan911)

Tue, 20 Dec 2011 07:24:21 GMT

lehpron

daleorama78

You completely missed the point........Every other board manufacturer used 32 also for the X58. Every other board manufacturer is using 40 lanes for the X79. Your point is moot.
I had a lot of points, don't generalize. Quite frankly, when PCIe 3.0 gets certified, there is reason to worry about that because each x8 3.0 will function like x16 2.0. Like I said, it will be several years before 3.0 spec graphics cards come to succeed 8 lanes, by then X79 will be dethoned.

To run at PCI 3.0, you will need a PCI 3.0 graphics card. So your point only applies to not one, but two future pieces of hardware and software releases.

So yes, there is a reason to worry - for those of us that have invested over $2200 in our 580s Hydros that are only, and will remain only, PCI 2.0 cards. If a PCI 2.0 card is inserted into a PCI 3.0 slot, it will run at PCI 2.0 only. So your "points" are muted unless addressing PCI 3.0 cards, which there are none ATM.

Re:PCIE Lane Population Rules (lehpron)

Mon, 19 Dec 2011 19:42:09 GMT

Looking at the X79 FTW visual guide page 2:

Slot 1: x8/x16 (switch)
Slot 2:   x1 (perm)
Slot 3:   x8 (perm)
Slot 4:   x4 (perm)
Slot 5:   x8/x16 (switch)
Slot 6:   x8 (perm)

I wonder if it is possible that slots 3 & 6 share bandwidth with 1 & 5 such that if they are populated, then they switch, thus 3-way SLI + PhysX as x8+x8+x8+x8. But JacobF didn't cover 2-way + PhysX, so it should be possible using slot 4 for PhysX and maintain dual x16's.

Looking at the X79 Classified visual guide page 2:

Slot 1: x8/x16 (switch)
Slot 2: x1 (perm), same as FTW
Slot 3: x8 (perm), same as FTW
Slot 4: x4 (perm), same as FTW
Slot 5: x8/x16 (switch)
Slot 6: x8/x16 (switch)

JacobF says it 8-8-16 for 3-way SLi, so similar to FTW, then 1 is affected by 3 and 6 is affected by 5. Except if nothing in 3 or 6, 1 and 5 remains x16.   If wanting 2-way SLi, must use slot 1 & 5. Any other add-in PCIe like PhysX or audio must go in 2 or 4, otherwise you loose dual x16.

Looking at the X79 regular SLI visual guide page 2:

Slot 1: x8/x16 (switch)
Slot 2: nothing
Slot 3: x8/x16 (switch)
Slot 4: x1 (perm)
Slot 5: x8 (perm)
Slot 6: x1 (perm)

JacobF says up top that 3-way SLI will enabled 16-8-8, so why is the top slot 1 allowed to switch, shouldn't it be permanent x16? Clearly a card occupying slot 5 affects slot 3. So unlike FTW, 2-way + PhysX will loose dual x16's.

daleorama78

You completely missed the point........Every other board manufacturer used 32 also for the X58. Every other board manufacturer is using 40 lanes for the X79. Your point is moot.

I had a lot of points, don't generalize. Quite frankly, when PCIe 3.0 gets certified, there is reason to worry about that because each x8 3.0 will function like x16 2.0. Like I said, it will be several years before 3.0 spec graphics cards come to succeed 8 lanes, by then X79 will be dethoned.

Re:PCIE Lane Population Rules (cpsusie)

Mon, 19 Dec 2011 17:49:28 GMT

Won't 16 lanes become an irrelevancy once pci-e 3.0 hardware is released? I understood that it would be limited to 8 lanes (with twice the content transmitted so effectively 16 lanes) on these x79 boards anyway. But I haven't followed it too closely. Never do > 2 graphics cards anyway.

Re:PCIE Lane Population Rules (daleorama78)

Mon, 19 Dec 2011 12:58:28 GMT

lehpron

daleorama78

The X79 is supposed to be such an upgrade over the X58 yet it runs the same 16x8x8 in the 3 way as the X58.

It is the Sandy Bridge architecture in the LGA2011CPU that sets it apart from Gulftown/Bloomfield, if that didn't sell the system for you, nothing will. That said, I don't know if these first batches have a cold-bug or if people aren't utilizing variable strap ratios to explain the lack of +6GHz overclocks for personal WR's, but I'd like to hope that will change.
X58 had 36 lanes in the PCH yet only 32 were utilized, I don't remember too many complaints at the time. That said, it still took almost four years since the introduction of PCIe 2.0 standard for single-GPU graphics cards to reach 8 lanes worth of bandwidth, begining with GTX480, which is the equivalent of 4 lanes of PCIe 3.0. The controller in the LGA2011 CPUs is default 3.0, we're all just waiting for final certification while it operates at 2.0.
My estimates are it will be another 2-3 years from now before future PCIe 3.0 single-GPU cards are reaching 8 lanes again, or fully saturating the 2.0 specification; meaning EVGA's 16-8-8 on their X79 won't be a hinderance until then (unless you pick up a dual-GPU card, but that's what dual x16's are for).
Anyone with an X58 still has those 2-3 years before those future backward compatible 3.0 cards need more than the 32 equivalent 2.0 lanes in their dual x16's. It is assumed those with 3-way intentions have already moved onto X79.

daleorama78

Besides its EVGA.......a FTW board.....a record breaking motherboard maker.
This is why I see loyality as being over-rated, you put them up on a pedalstal based on whatever chance experiences of good quality and expect them to return the favor when they aren't obligated because they are a business and not part of your family. I suggest you ditch the fan/loyality BS and only focus on why you upgrade at all. If you end up leaving EVGA for it, whoop-dee do.

daleorama78

You would think they would want any advantage they could get.
Note how giant SR-2 was compared to existing i5520 chipset dual-1366 boards, that's because EVGA attempted to satify as many customers as possible with features. Additional features cost money, how willing is anyone with the idea of paying extra to get EVGA to enable all 40 lanes in at least three usable x16 slots? I'm thinking very few, how do I figure? Because they sacrifice their desires to stay with EVGA, otherwise they would have moved on.

linuxrouter

I also have interest in the SR-X. However, one of the major selling points for me is being able to access all 80-lanes from two processors via the PCI-E slots. I'm now concerned that only part of those lanes will be accessible.

With respect, EVGA won't be the only dual-2011 maker, just the one that can overclock the pair of Xeons; thus weigh advantages with disadvantages and make a call. The closest equivalents to SR-2 would be these two SuperMicro boards with 56-lanes and 68-lanes enabled with dual i5520 chipsets. That said, with 36 lanes in each chipset, that's 72 total lanes not completely used by PCIe slots even on a regular GPGPU server board, so you guys can't just give EVGA a hard time.

You completely missed the point........Every other board manufacturer used 32 also for the X58. Every other board manufacturer is using 40 lanes for the X79. Your point is moot.

Re:PCIE Lane Population Rules (lehpron)

Mon, 19 Dec 2011 12:50:27 GMT

daleorama78

The X79 is supposed to be such an upgrade over the X58 yet it runs the same 16x8x8 in the 3 way as the X58.

It is the Sandy Bridge architecture in the LGA2011CPU that sets it apart from Gulftown/Bloomfield, if that didn't sell the system for you, nothing will. That said, I don't know if these first batches have a cold-bug or if people aren't utilizing variable strap ratios to explain the lack of +6GHz overclocks for personal WR's, but I'd like to hope that will change.
X58 had 36 lanes in the PCH yet only 32 were utilized, I don't remember too many complaints at the time. That said, it still took almost four years since the introduction of PCIe 2.0 standard for single-GPU graphics cards to reach 8 lanes worth of bandwidth, begining with GTX480, which is the equivalent of 4 lanes of PCIe 3.0. The controller in the LGA2011 CPUs is default 3.0, we're all just waiting for final certification while it operates at 2.0.
My estimates are it will be another 2-3 years from now before future PCIe 3.0 single-GPU cards are reaching 8 lanes again, or fully saturating the 2.0 specification; meaning EVGA's 16-8-8 on their X79 won't be a hinderance until then (unless you pick up a dual-GPU card, but that's what dual x16's are for).
Anyone with an X58 still has those 2-3 years before those future backward compatible 3.0 cards need more than the 32 equivalent 2.0 lanes in their dual x16's. It is assumed those with 3-way intentions have already moved onto X79.

daleorama78

Besides its EVGA.......a FTW board.....a record breaking motherboard maker.

This is why I see loyality as being over-rated, you put them up on a pedalstal based on whatever chance experiences of good quality and expect them to return the favor when they aren't obligated because they are a business and not part of your family. I suggest you ditch the fan/loyality BS and only focus on why you upgrade at all. If you end up leaving EVGA for it, whoop-dee do.

daleorama78

You would think they would want any advantage they could get.

Note how giant SR-2 was compared to existing i5520 chipset dual-1366 boards, that's because EVGA attempted to satify as many customers as possible with features. Additional features cost money, how willing is anyone with the idea of paying extra to get EVGA to enable all 40 lanes in at least three usable x16 slots? I'm thinking very few, how do I figure? Because they sacrifice their desires to stay with EVGA, otherwise they would have moved on.

linuxrouter

I also have interest in the SR-X. However, one of the major selling points for me is being able to access all 80-lanes from two processors via the PCI-E slots. I'm now concerned that only part of those lanes will be accessible.

With respect, EVGA won't be the only dual-2011 maker, just the one that can overclock the pair of Xeons; thus weigh advantages with disadvantages and make a call. The closest equivalents to SR-2 would be these two SuperMicro boards with 56-lanes and 68-lanes enabled with dual i5520 chipsets. That said, with 36 lanes in each chipset, that's 72 total lanes not completely used by PCIe slots even on a regular GPGPU server board, so you guys can't just give EVGA a hard time.

Re:PCIE Lane Population Rules (linuxrouter)

Sun, 18 Dec 2011 16:07:42 GMT

It would be nice if EVGA could at least give an explanation for the reasoning behind limiting lane allocation to 32-lanes.

I also have interest in the SR-X. However, one of the major selling points for me is being able to access all 80-lanes from two processors via the PCI-E slots. I'm now concerned that only part of those lanes will be accessible.

Re:PCIE Lane Population Rules (randman76)

Sun, 18 Dec 2011 15:58:22 GMT

I completely agree with daleorama78. Not being able to use 16x/8x/16x is no different than not supporting hyper-threading or multiple cores. It is something that Intel provided in their chipset. Why EVGA doesn't utilize all the X79 chipset resources is beyond me.

Re:PCIE Lane Population Rules (daleorama78)

Sun, 18 Dec 2011 05:35:17 GMT

Ofcourse it matters. Its the principle of the thing. The X79 is supposed to be such an upgrade over the X58 yet it runs the same 16x8x8 in the 3 way as the X58. Its supposed to run 16x16x8 natively. And when it comes to CUDA apps there a major difference,theres also a difference in gaming. Depending on who you listen to it may not be but 1-5% but a difference nonetheless. Besides its EVGA.......a FTW board.....a record breaking motherboard maker. You would think they would want any advantage they could get.

Re:PCIE Lane Population Rules (lehpron)

Sat, 17 Dec 2011 15:55:54 GMT

Forgive me if I'm wrong, but does it matter? I've felt that all cards will run least common denominator, that the single x8 of the three will force other two to run at x8 even though they'll say they are operating at x16. Meaning if you throw on some future 3-way GTX980, say they each use 12 of 16 lanes full operation, you won't get two at 12 and one at 8, they'll all run at 8. How far off am I?

Re:PCIE Lane Population Rules (randman76)

Sat, 17 Dec 2011 15:29:16 GMT

I would like to know as well but I do not think we will get an answer on this. This thread was created 4 days ago and so far no explanation from EVGA. If we do not get some kind of acknowledgement within the next couple of days I will RMA my board. The main reason why I was upgrading to the X79 chipset was for the ability to run 16x/16x/8x since it is a native function. But now, after I ordered the board and received it I find out that EVGA does not support that configuration. I should have realized that when I could not find the PCIE lane population rules in the manual. I am sure if they did publish that information there would have been far less purchases for their motherboards. Well, I had a good run with them. Started out with the 680i, 780i, 790i, 3-way classified, and the 4-way Classified. Sadly enough I do not think the X79 Classified will be staying on my list for long.

Re:PCIE Lane Population Rules (daleorama78)

Sat, 17 Dec 2011 14:33:50 GMT

I just wanna know why EVGA is apparantly the only ones that didnt do 16x16x8 3way SLI. Ive never owned any ASUS boards,all Ive ever owned is MSI,EVGA and Intel. Guess I may try and get a DX79si board if EVGA doesnt say exactly what the deal is.

Re:PCIE Lane Population Rules (cpsusie)

Fri, 16 Dec 2011 23:24:39 GMT

All I want to know definitively is where to put my PCI-E x1 sound card so my two graphics cards stay at x16.

Re:PCIE Lane Population Rules (michaelcollins)

Fri, 16 Dec 2011 07:45:22 GMT

Can you plz develope a Video Card Martix for the P67 and Z68 MB. And also include 2 way SLi + PhysX. Thank you for your time.