Enabling SLI

[_Maximus_]

Howzit everyone

I just installed a 2nd 460gtx 1GB - im keen to get SLI going. Ive installed the bridge and all power connectors etc.

For whatever reason, Nvidia control panel doesnt bring up the 'set SLI configuration' on the left task bar - so theres no way for me to enable SLI.

I can set my Physx to either of the cards, but it mentions nothing about SLI in the control panel at all.

Does anyone have any idea what I might be doing wrong? Is there any other way to enable SLI?

Also - not sure if its unrelated or not, but I cant view my desktop etc if I plug my cable into my 2nd GPU. My understanding was it shouldnt really matter which GPU I put my screen cable into.
If you need screen shots of anything just lemme know.

Thanks in advance!

Specs: 460 GTX 1GB (x2); i5 2500k; p8-p67 m-pro; 8GB RAM etc

 

[Pada]

Open up GPU-z (which you'll have to download if you don't have it already) and paste the screenshot of the 2x GTX 460's.
This should tell us if you have 2x GTX460's and not like 1x GTX460 + 1x GTX460 SE.

The GPU field should show GF104 for both graphics cards.

 

[_Maximus_]

They are both 460 GTX 1GB Hawks, no SE editions for me

http://i.imgur.com/6PMa7.gif

http://i.imgur.com/Xuvr1.gif

 

[Pada]

OK, so it seems you just require a BIOS update on that motherboard: http://www.tomshardware.com/forum/306418-30-asus-p8p67

Edit:
In what slots are you running the cards? Blue and white?

The cards would most likely run pretty hot in those 2 slots. The black slot runs at 4x, but I'm pretty sure the performance would be the same - or at least that was the case with my MSI X58A-GD65 motherboard when I ran my 2x MSI GTX 460 Cyclone OC 1GB cards.

I can't promise that the performance would be the same, so if you do have time, just run benchmarks / timedemo's to ensure that the performance is the same.

 

[_Maximus_]

Awesome find! Thanks so much, will update BIOS tonight and let you know how it goes.

As for the slot - Ive used the black 4x for now, the huge heat pipes on these cards make the second white slot impossible.
Ive read that one loses about 5% performance so im not too phased.

 

[Pada]

In my experience the performance loss on the 4x slot was less than 2% if not even the same as 2x 16x.

 

[_Maximus_]

Less than 2%? Thats awesome then! Nothing id even notice..

So Ive updated BIOS and still no luck :/
Starting to see red.. Thought setting this up would be easy.

Any other ideas? Do you rate it could be anything to do with the slots themselves?

UPDATE: SLI works if using the top two slots (so 8x 8x) configuration. However, the top card hits 85 - 90 within about 5 minutes of gaming. (theres about 0.5 cm between cards)
If I restart and place the card back on the bottom slot, the SLI option is gone. :/ Ideas?
Note the bottom lane works by itself if no GPU is placed in the top slot.

 

[Pada]

Hmm that sux.

I found someone with similar kind of issues with his P8P67 Pro (non-M model): http://www.overclock.net/t/1202302/asus-p8p67-pro-first-and-third-pcie-slots-cannot-enable-sli

Try setting the black slot to 4x speed in the BIOS.

If that still does not fix it, I'd suggest that you contact Asus, because in the manual (on p35 or section 1-23) it states that it can run dual graphics cards in:
1st slot + 2nd slot as 8x + 8x
or 1st slot + 3rd slot as 16x + 4x

Are you using the same flexible SLI bridge when the cards are in the 1st+2nd slots as when you have it in the 1st+3rd slots?

There was a good reason why I paid R2k for a 2nd-hand motherboard (Asus P6T Deluxe v2) that has 2 spaces inbetween its 16x PCI-E 2.0 slots: lower temperatures for SLI

If Asus can't help you, then perhaps sell the 2 cards and get a single GTX670 OC instead.

 

[_Maximus_]

Yep seems thats the exact issue im having - I wonder if its just a bad board or a manufacturing design flaw. Either way it sux!

Ye tried forcing the black slot to 4x (it was on automatic originally) and still no luck.
Also yes, I am using the same flexi bridge when I move the cards around.

I really hope Asus has good customer support - looks like ill be giving them a shout then. I guess this would fall under the warranty.. assuming they could fix it?

Either way thanks so much for the help! Gives me some sort of closure on this annoyance.

 

[CataclysmZA]

Uninstall all your Nvidia drivers using Revo Uninstaller. Then install the first card and run the latest Geforce updates. Shut down after the drivers bring the PC through a full reboot (into the desktop) and then install the second GPU and boot back into Windows, enabling SLI once you reach the desktop. That is the default method for setting up SLI.

For your motherboard, the bottom PCI-Express slot was never meant to be used for SLI purposes, only the top two. The bottom one is better suited for use with sound cards and high-end PCI-Express RAM drives because it feeds off the leftover lanes on the P67 chipset, due to there only being six SATA slots - the extra lanes two more ports would have used have been repurposed for the PCI-Express 4.0 slot. This is also the reason why H77 boards can't to triple-SLI or Crossfire - there just aren't enough leftover PCI-Express 2.0 lanes. In P67 boards USB 3.0 controllers also ate up a varying amount of lanes depending on how close to the final USB 3.0 standard the controllers are, because they weren't natively built into the motherboard chipset like they are now with H77/B75/Z77.

You can, however, run a card in that 4x slot on its own, because it doesn't have to fight for IRQ space with an already-laden motherboard supporting two graphics cards in tandem.

 

[_Maximus_]

Uninstall all your Nvidia drivers using Revo Uninstaller. Then install the first card and run the latest Geforce updates. Shut down after the drivers bring the PC through a full reboot (into the desktop) and then install the second GPU and boot back into Windows, enabling SLI once you reach the desktop. That is the default method for setting up SLI.

Ill do exactly what you mention here - Im quite sure I have done it already but just to be sure ill do it again.

For your motherboard, the bottom PCI-Express slot was never meant to be used for SLI purposes, only the top two. The bottom one is better suited for use with sound cards and high-end PCI-Express RAM drives because it feeds off the leftover lanes on the P67 chipset, due to there only being six SATA slots - the extra lanes two more ports would have used have been repurposed for the PCI-Express 4.0 slot. This is also the reason why H77 boards can't to triple-SLI or Crossfire - there just aren't enough leftover PCI-Express 2.0 lanes. In P67 boards USB 3.0 controllers also ate up a varying amount of lanes depending on how close to the final USB 3.0 standard the controllers are, because they weren't natively built into the motherboard chipset like they are now with H77/B75/Z77.

You can, however, run a card in that 4x slot on its own, because it doesn't have to fight for IRQ space with an already-laden motherboard supporting two graphics cards in tandem.

Im slightly confused - are you saying my motherboard definitely cannot run SLI in the 3rd lane?

If you are correct, it means that might motherboard manual is rubbish - I include a screenshot of the particular page regarding multi GPU setup on my board: http://i.imgur.com/JAAsP.png

Also, I phoned Asus and they said the board should be able to run SLI in the 3rd lane. They said they would replace the board if it didnt.
After reading your comment however, it makes me wonder if it will actually be able to run 16x 4x in SLI mode - it might be able to run two GPUs in 16x 4x, but not in actual SLI mode. Is this what you are saying?
Do you think I could ask Asus for a different board if this is the case? Because everything on their site points toward this board being able to run multiple GPUs in SLI mode. (quad mode SLI)

Thanks for the detailed response, it makes a lot of sense.

 

[CataclysmZA]

Im slightly confused - are you saying my motherboard definitely cannot run SLI in the 3rd lane?

Also, I phoned Asus and they said the board should be able to run SLI in the 3rd lane. They said they would replace the board if it didnt.

What I'm saying is you can run SLI in the two top slots, but not SLI in slot one and slot 3. Sandy Bridge wasn't designed that way. I read the manual as well and I believe its incorrect - ASUS support is, AFAIK, likewise not giving you the right information.

When Intel launched Sandy Bridge, many reviewers were concerned that it just didn't have enough resources to support multiple graphics cards. There are 16 native PCI-Express 2.0 lanes to the CPU as well as an extra four that could be used for anything else. Sandy Bridge-E and the Nehalem-based Core i7 chips have anything from 32-40 PCI-E lanes available for use, which is why any site that does graphics card reviews uses a LGA2011 board and compatible CPU for their multi-card configs.

Ivy Bridge is also limited to 16 lanes, but this time they are of the PCI-Express 3.0 variety. Its entirely possible to design a Z77-based board with four slots running at 4x each, with the same bandwidth and speed/throughput as PCI-E 2.0 8x. There's just the slight problem that many manufacturers don't do this, sadly.

Do you think I could ask Asus for a different board if this is the case? Because everything on their site points toward this board being able to run multiple GPUs in SLI mode. (quad mode SLI)

They'll likely refuse your request because as you've confirmed yourself, SLI does work on the board. And the quad-GPU thing is actually a misleading statement - you can have quad-SLI if you put two GTX590 in there, for example.

As for your overheating, either underclock the cards, raise the fan speed profiles or put in extra fans for more airflow.

 

[_Maximus_]

What I'm saying is you can run SLI in the two top slots, but not SLI in slot one and slot 3. Sandy Bridge wasn't designed that way. I read the manual as well and I believe its incorrect - ASUS support is, AFAIK, likewise not giving you the right information.

When Intel launched Sandy Bridge, many reviewers were concerned that it just didn't have enough resources to support multiple graphics cards. There are 16 native PCI-Express 2.0 lanes to the CPU as well as an extra four that could be used for anything else. Sandy Bridge-E and the Nehalem-based Core i7 chips have anything from 32-40 PCI-E lanes available for use, which is why any site that does graphics card reviews uses a LGA2011 board and compatible CPU for their multi-card configs.

Ivy Bridge is also limited to 16 lanes, but this time they are of the PCI-Express 3.0 variety. Its entirely possible to design a Z77-based board with four slots running at 4x each, with the same bandwidth and speed/throughput as PCI-E 2.0 8x. There's just the slight problem that many manufacturers don't do this, sadly.

I see what you mean now I always thought the motherboards used in reviewing SLI 16x 4x setups would have been based on the same process as any of the p8p67 motherboards - never picked up that there would be a difference (a somewhat uneducated assumption it seems).

They'll likely refuse your request because as you've confirmed yourself, SLI does work on the board. And the quad-GPU thing is actually a misleading statement - you can have quad-SLI if you put two GTX590 in there, for example.

As for your overheating, either underclock the cards, raise the fan speed profiles or put in extra fans for more airflow.

Haha cant believe this.. the fact that they advertise 'quad' GPU as two 590s... Seems like a bit of a hack to me, but hey, they got away with it.

Thanks so much for the consolidation. I think this answers all my questions perfectly.
Might well just get rid of the 2nd card and stick with one 460 until I NEED to upgrade, the heat issue and the framerates that jump around are getting a bit annoying.
Thanks again!