Sli 780ti problems

[mattias1172]

yes ive tried flipping them, different slots, ive tested both of the cards and they both manage 3500MHz in heaven, they just cant do it in sli together.  There is something that is automatically down clocking the gpu and i dont know why or how to resolve it.  

[dragoon20005]

yes ive tried flipping them, different slots, ive tested both of the cards and they both manage 3500MHz in heaven, they just cant do it in sli together.  There is something that is automatically down clocking the gpu and i dont know why or how to resolve it.  

do you got a spare HDD or SSD?

 

i will suggest install a fresh OS in there with just you basic stuffs and drivers

 

then run the benchmarks with the fresh OS

[MrBucket101]

yes his GPU are the classy

we also flipped the GPUs around

his mobo has the feature to run with one GPU by flipping a switch on the mobo

what is weird is that with one GPU power

it work fine

but not in dual mode

What about the rails on his PSU?

Does he have the second GPU on a rail with enough amperage? Check the manual. What about the extra PCI-e lane power plug?

780 TI's are power hungry SOB's. When I was benching my 780ti, I actually had to plug in the additional power for the PCI-e lanes. Without it I couldn't get the card past 1300mhz, my mobo/PSU kept cutting the power to to save itself. With the extra power I successfully benched 1400MHz.

Did the math afterwards and with that single card at those clocks/voltages I had nearly maxed out my PSU.

@mattias1172

[dragoon20005]

What about the rails on his PSU?

Does he have the second GPU on a rail with enough amperage? Check the manual. What about the extra PCI-e lane power plug?

780 TI's are power hungry SOB's. When I was benching my 780ti, I actually had to plug in the additional power for the PCI-e lanes. Without it I couldn't get the card past 1300mhz, my mobo/PSU kept cutting the power to to save itself. With the extra power I successfully benched 1400MHz.

Did the math afterwards and with that single card at those clocks/voltages I had nearly maxed out my PSU.

@mattias1172

i dont know if that matters he using a 1K watt Corsair RM series

[mattias1172]

i dont know if that matters he using a 1K watt Corsair RM series

According to PCPP I should have 100w to spare.

[MrBucket101]

i dont know if that matters he using a 1K watt Corsair RM series

  

According to PCPP I should have 100w to spare.

Not too bad tHen

Install corsair link and look at the amperage on your 12V

You should be able to tell if each card is getting adequately fed, based on the amperagebeing drawn

[dragoon20005]

According to PCPP I should have 100w to spare.

without any OC

 

it should work

 

try the fresh install method on a spare HDD or SSD

 

 

 

if that fails maybe a bigger PSU

[mattias1172]

Alright.  I need another product key to download another copy, so i actually clicked your link dragoon .  Its gonna take forever to download so ill post here after.  In the meantime if anyone has any ideas, im all for it.  

[Sintezza]

Sorry for the much delayed response.  Very busy day today .  Anyways, yes i have nvidia geforce experience completely uninstalled and have had it uninstalled for the majority of the benchmarks.  I have updated gpu-z and will post the screenshot here.  I even updated my mobo bios to the newest non beta one and turned all the asus ai suite 3 setting (and bios settings) to performance mode.  I am still having the same issues.

 

 

gpuz.gif

 

Well was your card at idle here?

 

cause if so, then this is normal, wenn a card is idleing, it automaticly gets back to pci-e 1.1.

but if you are going to run a game it should jump to pci-e 3.0 mode.

This is a powersaving feuture.

[dragoon20005]

Well was your card at idle here?

 

cause if so, then this is normal, wenn a card is idleing, it automaticly gets back to pci-e 1.1.

but if you are going to run a game it should jump to pci-e 3.0 mode.

This is a powersaving feuture.

the thing is he was testing the GPU with benchmarks like valley

 

but the 1st gpu is just not working

[Sintezza]

the thing is he was testing the GPU with benchmarks like valley

 

but the 1st gpu is just not working

 

Hmm thats strange, wenn the card works correctly and being recognized in windows, then it should be some of a setting somewhere.

[dragoon20005]

Hmm thats strange, wenn the card works correctly and being recognized in windows, then it should be some of a setting somewhere.

yea i was thinking about OS problems because we tried everything in the books from gpu swapping, driver install 

 

testing one gpu and such

 

still no dice

[Sintezza]

yea i was thinking about OS problems because we tried everything in the books from gpu swapping, driver install 

 

testing one gpu and such

 

still no dice

 

i readed something about precision X, could have something to do with this problem..

Its better to disable this if im right?

[dragoon20005]

i readed something about precision X, could have something to do with this problem..

Its better to disable this if im right?

I not really sure

 

@mattias1172

 

which OC software are you using?

[MrBucket101]

@dragoon20005 I still think it's a power delivery issue. His PSU supports corsair link, he can go check and see if he's maxed out the amperage. Just cause he's got 1000W doesn't necessarily mean he's got enough amps on the 12V rail for the 2 cards.

He could also try enabling k-boost in PX to force both cards to run at the 3D clocks 24/7

[dragoon20005]

@dragoon20005 I still think it's a power delivery issue. His PSU supports corsair link, he can go check and see if he's maxed out the amperage. Just cause he's got 1000W doesn't necessarily mean he's got enough amps on the 12V rail for the 2 cards.

He could also try enabling k-boost in PX to force both cards to run at the 3D clocks 24/7

ok we just have to wait for OP to reply us

 

i am stumped with this issue

[mattias1172]

I believe I have a copy of precision x on the computer, but I use the Asus ai suite 3 to do basic overclocking along with afterburner. I don't have the corsair link cable for my psu so I'm not in a position where I can do that right now. I ran xfire 280x's with this psu and it worked just fine, although I am aware 780ti's use a lot more power.

[MrBucket101]

I believe I have a copy of precision x on the computer, but I use the Asus ai suite 3 to do basic overclocking along with afterburner. I don't have the corsair link cable for my psu so I'm not in a position where I can do that right now. I ran xfire 280x's with this psu and it worked just fine, although I am aware 780ti's use a lot more power.

You really only need one of them installed. AB or PX

 

also, this is from the EVGA website.

 

 

 

Requirements

Minimum of a 600 Watt power supply.

(Minimum recommended power supply with +12 Volt current rating of 42 Amps.)

Two available 8 pin PCI-E power connectors

Total Power Draw : 250 Watts

 

I looked up the specs on the RM1000, and it has a maximum amperage of 78A on the 12V rail.

 

They're usually pretty overzealous when they spit out the minimum power requirements. But with 2 of the 780TI's you could very well be pushing the amperage limit of your PSU. This could explain the shitty performance, one of the cards is being starved.

At this point, it's a crap shoot really. I would do a full OS reinstall to eliminate any software problems.

[mattias1172]

I looked up some reviews and other info on the psu and supposedly it's actually rated at 83.3A and should easily be able to power three way sli. Regardless, it very easily could be an OS problem. I'm not sure what it is, but it seems my copy of 8.1 x64 is very buggy. I'll have to see what I can do about getting another copy of windows to install on it. As a side note, does anyone know if Ubuntu supports all the necessary drivers and software? I'd love to switch out of windows into Linux.

[TymmVonD]

I had xfire 290s before I swapped in the 780 TIs. I was getting worse performance as well. I tried uninstalling AMD drivers, reinstalling nVidia drivers. No help....So I ended up reinstalling Win8.1. It's way better now, but my GPUs still don't run at 100% all the time with vsync off. There is something a bit off about these Tis still.

 

I just ran Valley maxed out at 1080 and scored 4693. 

[mattias1172]

I had xfire 290s before I swapped in the 780 TIs. I was getting worse performance as well. I tried uninstalling AMD drivers, reinstalling nVidia drivers. No help....So I ended up reinstalling Win8.1. It's way better now, but my GPUs still don't run at 100% all the time with vsync off. There is something a bit off about these Tis still.

 

I just ran Valley maxed out at 1080 and scored 4693.

I haven't run valley yet, but on heaven with the ti's I score around 1500...My first card runs at 3500MHz constant while my second doesn't run above 810MHz.

[dragoon20005]

you say your OS was buggy 

 

in what way was it buggy?

 

was the ISO downloaded from here?

 

http://blogs.technet.com/b/canitpro/archive/2014/03/19/windows-8-1-tips-how-to-download-the-windows-8-1-pro-iso.aspx

 

we can't be sure if the PSU may be failing or not

 

you should be aware the RM series do use cheap caps in a high end PSU

 

 

again try to reinstall the OS using the ISO from Windows officially

 

if that fails

 

swap the PSU to a higher wattage

[mattias1172]

Well quick update.  I have yet to re install my OS. To do so would be a huge hassle so im still trying to find other ways.  I have managed to solve the problem with the card running at 1.1 instead of 3.0.  However, in benchmarks, the card is still being under clocked somehow i have yet to determine.  Any other ideas is greatly appreciated.  

[dragoon20005]

Well quick update.  I have yet to re install my OS. To do so would be a huge hassle so im still trying to find other ways.  I have managed to solve the problem with the card running at 1.1 instead of 3.0.  However, in benchmarks, the card is still being under clocked somehow i have yet to determine.  Any other ideas is greatly appreciated.  

indeed OS re install is a hassle but we need to rule out software troubles

 

if that fresh OS did not help

 

we may point to faulty PSU or GPUs 

[mattias1172]

indeed OS re install is a hassle but we need to rule out software troubles

 

if that fresh OS did not help

 

we may point to faulty PSU or GPUs 

ik ive asked it over and over, but can you think of anything that may be causing the card/mobo to underclock itself to save power? I fixed the 1.1 to 3.0 issue by looking deeper into the nvidia control panel and found a power saver feature that was enabled.  So i told it to prefer max performance and it solved that issue.  Also i don't have the original OS install disk so i can't to a fresh wipe and reinstall without spening another $100.  Do you know if Linux (Ubuntu specifically) supports the drivers needed?