cancel
Showing results for 
Search instead for 
Did you mean: 

Rampage IV Extreme PCI-E Configuration

Dartmaul
Level 12
Few days ago I got 2nd 7970 VGA and now I have some trouble with PCI-E width.

As was announced by Intel, LGA2011 chips have 40 PCI-E v3 channels.

Right now I have 2 HD7970 cards (x16), One RevoDrive SSD (x4) and Xonar DX soundcard (x1), 37 channels total.
Seems that SSD's and Sound card's ports are operating in x8 mode that makes them to fall outside the limit of CPU.
In the result, the second VGA port is degrading to x8 mode to pass the limit of 40 channels.

Since I don't have H2O cooling on graphic cards yet, the second one is blocking PCI-E v2 x1 slot, so I can't plug the sound card in there.

So the question is:
Can I force secondary ports to operate in x4 (or x1) mode to keep both VGA's ports in x16 mode?

(I know that performance impact of x16 comparing to x8 mode for 2nd GPU is very low but anyway)
27,198 Views
12 REPLIES 12

HiVizMan
Level 40
Pretty sure you can select what the PCie lanes will run at. However I do not think it will help. Simply because you have all the PCIe lanes populated. I think that is going to pretty much dictate how the lanes operate.

I will pull out my X79 board and have a look on Monday or Tuesday.
To help us help you - please provide as much information about your system and the problem as possible.

rEd2k
Level 7
I would also like to have this question answerd. I have 2 GTX 590's and 1 GTX 460 (For physx) and an Auzentech Hometheater HD (X-Fi) audio card. My cards are plugged in in this fashion and I THINK they are running at these speeds: GTX590,soundcard (on shared 8x port),GTX590,GTX460 running @ 16x,1x,16x,8x. I have tried many times to set it up as: GTX590,GTX460,GTX590 as the mobo simulator indicates that this is really the only way to get all 40 lanes of PCI-E and that I would have to leave out the sound card as the darn PCI-E 1X slot is covered by the last video card plugged into the board.

The simulator does in fact state that the PCI-E 1X slot being populated would be ok and that I could still use all 40 lanes and the +1 extra for the sound card if I was able to plug it in of course. BUT the current config that I do use seems to be working the way I want anyways! Though I would need someone to confirm if what I think is true... Even though I have the cards plugged in as GTX590,Sound,GTX590,GTX460 when I run GPU-Z it states that I am in fact getting a 16x,1x,16x,8x pcie lane setup which is perfect and exactly what I want. The only thing is and what I'm not sure about is that 1X PCI-E in the middle there, as GPU-Z doesn't actually say it's there as it's only meant to detect video cards, though the rest of the cards do report 16x,16x,8x, respectively.

So my question is: Am I ACTUALLY GETTING the PCI-E lane layout as I've stated? It seems to be that I am, but the Asus simulator for the PCI-E lanes being occupied suggests otherwise, supposedly forcing me to make the 16x,8x,16x card layout to be the only option.. I have a feeling that when in windows (or just an undocumented feature in the mother board) does remap the lanes to occomidate the configuration that I currently use, but this is just a guess of course 😛

The simulator also states that if I am using my current layout that the setup would be 16x,1x,8x,8x but in windows GPU-Z says different. I don't know what to believe and it's frustrating to say the least. Also the only reason that I am NOT using the 16x,8x,16x layout like I wanted (as Asus wants I should say) is because I have issues with the display driver and/or mobo detecting that there is a card in the second PCI-E slot, in this case my GTX460 and I always have to mess around to make it re-detect it, also requiring a reboot just to make it all gel together.

Like What the heck is that all about?? I have tried a fresh reinstall of the os and many different driver revisions and mobo bioses ect ect ect ect ect ect ect ect ect ect ect ect ect ect!!!!!!!!!!!! As you can tell I've given up on EVER trying to make that work again because for some reason, even when I finally do get it working, I am left with a COVERED 1X PCI-E slot that I can't use.. And yes, I have found right angled 90 degree PCI-E 1x v2.0 lane extension cables on the net that would solve that delema.. But in the end it's just too frustrating that I can't just turn on my computer and all the cards are present and are working even if I had purchased and installed said extension cable... *Sigh*

I really hate how Asus layed out this board this time around, this has always been a problem for me with other boards as well if the manufacturer doesn't place the 1X PCI-E port away from the rest. I believe the only boards I've ever owned where they considered this more often was the evga ones. There are many others that also do this and Asus does it as well but very rarely on the big ticket boards, it's always hit and miss when it comes to that one tiny little feature that I wish was a standard on ALL boards out there... Simpley placing that crummy little 1X port away from everything else is just too much to ask for a $450 board I guess... Sorry that I was ranting a little here..

@ Dartmaul: Why don't you try what I'm trying and see if you get the same result? It would be great if you have any success and please, PLEASE let me/us know if you do get the same result. Of course in your case it would be a: 7970,sound,7970,SSD and hopefully you will get: 16x,1x,16x,4x layout that way your two big video cards can see 16 lanes each and hopefully run at full speed! I don't know if GPU-Z is the best way to tell that the lanes are truly what it says they are but it's worth a shot and I hope that GPU-Z is something I/we can rely on for accurate reporting about the lanes and their TRUE speed.

If anyone can get back to me and let me know what the real story is all about with the RIVE PCI-E layout stuff that would be awesome, any help is greatly appreciated 😉

The sound card will go in slot 6 (bottom slot). Your video cards go in slots 1, 2, and 4. Only the card in slot 1 will run x16, sorry. The other two and your sound card will run x8. See page 2-16 of the user guide. I hope this helps.

i dont no but i have my RIVE set up with 2 gtx560 insli mode and a xonar DX 7.1, i have both of my gpus in slots #1 and second gpu in slot #3 both are running at 2.0 x16 and then i have my Xonar DX in slot #2b(black slot). so both of my gpus are running at 2.0x16 and the xonar sound card running at x1, so i think this is how you should set up your cards except that the Revo drive you should pu it in the last slot #4 to get the best bandwidth from your cards

HiVizMan
Level 40
The joker in the pack is the revocard, that does some strange stuff to the overall PCIe configuration I have noticed in the past. Not sure with later BIOS updates and sadly I can no longer test as my Revo has moved on to nand heaven.
To help us help you - please provide as much information about your system and the problem as possible.

HiVizMan wrote:
The joker in the pack is the revocard, that does some strange stuff to the overall PCIe configuration I have noticed in the past. Not sure with later BIOS updates and sadly I can no longer test as my Revo has moved on to nand heaven.


Seems to be so. I had a lot of problems with that SSD in the past.
Actually the only reason I bought it was my previous Rampage II Extreme that hasn't any SATA3 ports.
I'm already looking for some replacement (maybe OCZ Agility or something)

Thank you guys!

rEd2k wrote:

@ Dartmaul: Why don't you try what I'm trying and see if you get the same result? It would be great if you have any success and please, PLEASE let me/us know if you do get the same result. Of course in your case it would be a: 7970,sound,7970,SSD and hopefully you will get: 16x,1x,16x,4x layout that way your two big video cards can see 16 lanes each and hopefully run at full speed! I don't know if GPU-Z is the best way to tell that the lanes are truly what it says they are but it's worth a shot and I hope that GPU-Z is something I/we can rely on for accurate reporting about the lanes and their TRUE speed.

If anyone can get back to me and let me know what the real story is all about with the RIVE PCI-E layout stuff that would be awesome, any help is greatly appreciated 😉


1st of all: 16x,1x,16x,4x is impossible because of 4th and 6th ports are linked and have x16 for both.
I've tried every possible mix of ports and devices.
There's only 2 ports on RIVE which can run in x16 - VGA's will stay there. There's no sense to move them.
About 2nd and 3th ports which are linked on the same channel - in my case - seems that Revo SSD really makes some trouble here, when install soundcard and SSD in 2nd and 3th port - works only one device (just like virtual configuration said)

So the complete situation looks like that:

__________________________________________________
|_________|________________________________________| - 1st port, x16 width in every case




__________________________________________________
|_________|________________________________________| - 2nd, linked with 3th, x8 for both
If ^ 2nd runs in x8 mode v 3th is off!
__________________________________________________
|_________|________________________________________| - 3th, linked with 2nd, x8 for both

__________________________________________________
|_________|________________________________________| - 4th, can run x16, linked with 6th, x16 for both

_________________
|_________|_______| -5th, PCI-E v2.0 x1 port

__________________________________________________
|_________|________________________________________| - 6th, linked with 4th, x16 for both

x16 (1st) + x8 (2nd and 3th) + x16 (4th and 6th) = 40 (CPU limit)

@ rEd2k: For you, my friend, there is only one way to make your 590's run x16 and 460 run x8:
1st slot - 590 x16
2st slot - 460 x8
4th slot - 590 x16
6th slot - EMPTY

I can't say is 5th x1 v2.0 port included in CPU's 40 lines or not, but CPU has 40 PCI-E v3.0 lines and this port is v2.0.




For me the question is:
Is it possible to share x8 within 2nd and 3th ports? (That probably means to force one of these to run x4)

rEd2k
Level 7
Thank you all for your comments 🙂

Dartmaul, your explanation is very well presented, good job man! It's better than my brick of text to read lol. Though I do already know everything that you've explained already, it still doesn't explain why GPU-Z is reporting that when I have my config setup like this:

Slot 1: 590 X16
Slot 2: Empty
Slot 3: Sound card
Slot 4: 590 X16 <-Should be running @ 8X but GPU-Z states it's running at 16X
Slot 5: Empty
Slot 6: 460 X8

Why GPU-Z reports SLOT 4 TO BE RUNNING AT 16X speed?? And to me it makes sense that IT SHOULD NOT BE running at 16X, it SHOULD be 8X as everyone has pointed out, including the manual and the simulator... Like HUH??!! That's why I'm confused about it all. I guess I shouldn't rely on what GPU-Z is telling me then? I have a sneeky suspision that GPU-Z is reporting it that way because of the NF200 chip in my GTX 590 dual card setup, and it SEES 16X lanes when in fact the motherboard is only running at 8X in SLOT 4. It could also be because everything I'm running is PCI-E V.2.0 and the board + cpu have more of those lanes to accomidate my setup better?

I see that my GTX 460 is running at 8X which leads me to believe that in fact my GTX 590 actually IS running at 8X in SLOT 4 😞 If that's truly the case then I guess I will have to go and put all three cards in the slots suggested by everyone, it's just that I think there is a problem when using those top two SLOT 2/3. Like I stated earlier, my GTX 460 always fails to detect on startup in SLOT 2. Otherwise I would already be using that slot instead of SLOT 6.

Dartmaul, I wish I could help you better with your setup, cuz I know that you SHOULD be able to run your cards in those slots as you see fit, darn it anyways! In my experience I have found that when there are shared PCIE slots like the slots in 2/3 you will have to run cards that have the same link width to be able to use the ports correctly, and this is not always the case but I've had a 4X card run at 1X cuz on a different board the other shared slot was an 8X card even though the shared slots were 16X ports. Maybe this is also the case for the RIVE. I also found that when using shared slots in any computer it's usually just best to only use one of those ports and never populate the other one to avoid issues.

I do believe you are in the same (although different) position I am in, I'll probably have to move my GTX460 to SLOT 2 again and cross my fingers that I figure out a way to make the stupid thing work, and you and I will also have to buy a PCI-E 1X V2.0 extension cable that can plug into SLOT 5 just to get our sound cards to work with our setups (if of course that's possible for you in the case you have).

If anyone can confirm my findings with that darn GPU-Z for a similar setup and just tell me if the software is reporting false info that would be a big help. If the software is in fact telling us that we CAN use the other slots in a different way for what ever reason, that would be excellent news and useful by many. I'm sure we can't do that, but heck, it's worth a try 😉

Dartmaul
Level 12
The only thing that comes to my head as an explain of this fact is that PCI-E v3 is 2 times faster that PCI-E v2.
So the real speed of PCI-E v3 x8 and PCI-E v2 x16 is the same.

And that's the difference between our setups. 7970 supports PCI-E v3 and 590 doesn't.

Anyway, to solve our problem we need some additional info about RIVE PCI-E slots specification. (And probably about PCI-E itself)

rEd2k
Level 7
Dartmaul wrote:
The only thing that comes to my head as an explain of this fact is that PCI-E v3 is 2 times faster that PCI-E v2.
So the real speed of PCI-E v3 x8 and PCI-E v2 x16 is the same.

And that's the difference between our setups. 7970 supports PCI-E v3 and 590 doesn't.

Anyway, to solve our problem we need some additional info about RIVE PCI-E slots specification. (And probably about PCI-E itself)


I think your on to something there Dartmaul, and yes, we really need more info about the RIVE PCI-E layout when it comes to these situations. I'm hoping that (when it comes to PCI-E 2.0 anyway) that Asus or Intel did some magic to allow for the lanes to be more flexable and can remap where they go to in my case. Though, soon enough, I will eventually have some PCI-E 3.0 cards in there and it's good to know exactly how these limitations can affect the card setup invovled.

Dartmaul, have you tried setting the option in the bios to allow for PCI-E 3.0 on SLOTS 1 & 4 but change the SLOTS 2A/2B to be PCI-E 2.0? Maybe that might do the trick after seeing how things are mapped for me on my board maybe using PCI-E 2.0 on those slots will give it more flexability? The option is under "Advanced->System Agent Configuration" and it's the last option for those ports called "PCIE_X8_2A and PCIE_X8_2B Link Speed" In the bios. Let me know if anything changes 🙂