Power needs (TTL brought me here)

[CCISolitude]

Morning all.

In the last week and half, I've built myself a whole new rig as my old one was, well, just a bit old really - not bad as such (i7-2600K / GTX 680 / 16 GB @ 1600) just bits of it were getting on for 4 years old or so, and it was time for a refresh.

So I did all my usual research, ummed and aahed about what case I wanted, what kit I wanted as a base line, whether or not I wanted to hold off for another 6 months for DDR 4 or Nvidia's 8xx line - in the end though, I built this:

i-4770K (with a BeQuiet Dark Rock Pro (version 2 I think, it's the one piece that transferred from the old rig)
Asus Maximus VI Formula
4x 4GB Kingston @ 2400
2x Asus GTX 780 Ti DC2OC
3x SSD (1x Corsair, 2x Samsung)
1x 1TB platter
1x Blu-Ray

All housed in a Stacker 935, with the 915R unit mounted below the 935 housing the PSU, platter and Blu-Ray to try and keep some separation for the heat sources.

The PSU being a BeQuiet PowerZone 850W.

And herein lies the question - when I was sketching out the build, I rattled through the usual online calculators, factored the math for the setup and at highest, was still expecting to see around 100W of head room at full load.

However, I've had one or two issues with the build - and I'm trying to track it down.

For instance, I went back to Assassins Creed III last night to finally finish it off, ramped the details up to maximum - including the use of TXAA - and after just 10/15 seconds, all the fans were at full tilt, the game froze as did the O/S and it needed a hard reset.

I've encountered similar symptoms with Tomb Raider.

Oddly though, Crysis 3 maxxed out is perfectly fine (good lord it really is a pretty engine).

Now as the subject title says, TTL brought me here.

I was scouring this morning for some more information, re-running the calculations again - and I found his video testing an i5 with a single 780Ti (I don't know if its an OC version like mine, but given who it is, I suspect it probably is) and he was pulling a maximum of 430 or so watts during testing with Unigine and OCCT. Now allowing certainly for a bit of extra wattage since I'm running an i7 instead of an i5 - but countering that because I'm not running a Corsair AIO - I can't imagine for the life of me that the second 780 (which, I should point out, playing AC3 was NOT in SLi mode, so the card was fairly idle) that I'm hitting the max my PSU can provide.

So the question is, am I having a problem with my PSU? Is it maybe faulty? Do I need some better power? Or are my TXAA issues (AC3 ran fine when not using TXAA) to do with something else?

 

[Excalabur50]

I suspect it may be a power supply issue do you have another that you can test with? P.S Welcome to the forums

 

[SieB]

A 850w PSU is enough power, adding a second card would only add around another 250-300w usage.

Your PSU could be faulty but it is strange that you don't get a problem with Crysis 3, which would have more power usage in SLI than ACIII would with a single card.
Given that, I would think it was a problem with your cards and or drivers.

I can't say for sure though but you definitely have enough power wattage wise. The fact that your PC crashes with ACIII on a single card using less power than Crysis 3 in SLI I don't think it is your PSU.
But there is still a possibility that it could be.

 

[CCISolitude]

AC3 only crashed when using TXAA though - once I'd come off TXAA - it ran for about 4 hours with zero issue.

Other games have been running fine - running 1 monitor off each card with Eve clients has been smooth as a smooth thing - I'd have thought if it was truly an ill PSU - I'd have seen more errors manifesting themselves?

Unless it's just ill at a very high draw.

I suspect it may be a power supply issue do you have another that you can test with? P.S Welcome to the forums

Not another in the same range no, the only other I've got is 500W.

Dammit - something else I should have put in the OP - because I was trying to save myself some grief - its NOT a clean install.

I ported direct from the old mobo to the new mobo.

Yes yes yes, I know, not really the thing to do, but my lazyness is pathological and I was in a rush on build day to have it ready for that's weekend LAN session.

 

[Excalabur50]

Take one card out and use the 500 watt and try the TXAA and run it and see if it does the same thing if it does then you know it's the power supply if not then you can look for other things

 

[SieB]

AC3 only crashed when using TXAA though - once I'd come off TXAA - it ran for about 4 hours with zero issue.

Other games have been running fine - running 1 monitor off each card with Eve clients has been smooth as a smooth thing - I'd have thought if it was truly an ill PSU - I'd have seen more errors manifesting themselves?

Unless it's just ill at a very high draw.

Sounds more of a problem with your cards and or drivers then if it only happens with TXAA on.

If it was the PSU you would definitely have problems running Crysis 3 maxed out which causes some of the highest power draw out of many games.
Plus the fact that ACIII only uses one card and less than half the power Crysis 3 would with two cards.

Try rolling back to older drivers and see if that helps.

 

[CCISolitude]

I just tried AC4.

HBAO+ High
MSAA 4x
Environment Very High
God Rays High
Reflection High
Shadows Quality Very High
Texture Quality High
Volumetric Fog On


I got through the intro sequence on the water fine, had the little cut scene with some other sailor chappy, started to chase after him, then it locked up - monitor blanked out, no signal. Sound was still going though.

Nothing of note in event logs.

System is in SLi mode.

Going to take it out of SLi mode and try again.

 

[tinytomlogan]

I dont think its power, it could actually be a duff card. Try it one card at a time.

 

[CCISolitude]

Well that still didn't work.

I've just taken out the top card and am going to try again on just the second card.

Yes, it's not in what would be considered the primary slot. But I'm looking at a double blind test as it were.

if it runs fine - then I have to consider that the fault may lie with the primary GPU or PSU - at which point I can swap over the 2 GPU's and test again.

If it crashes - then the problem may still lie with the PSU - but I'll be damned if I can see quite why.

 

[SieB]

Well that still didn't work.

I've just taken out the top card and am going to try again on just the second card.

Yes, it's not in what would be considered the primary slot. But I'm looking at a double blind test as it were.

if it runs fine - then I have to consider that the fault may lie with the primary GPU or PSU - at which point I can swap over the 2 GPU's and test again.

If it crashes - then the problem may still lie with the PSU - but I'll be damned if I can see quite why.

It could be caused by drivers as well, try rolling back to the last lot of drivers and the ones before that if you still get problems.

 

[tinytomlogan]

Its not the PSU.

 

[CCISolitude]

Well I've just ran for an hour or so on the other GPU - no problems. Going to swap cards. See what happens.

 

[CCISolitude]

Right then, so after a bit of swapping back and forth - looks like the problem is with one of the GPU's.

Just ran Tomb Raider on #2 for about 45 minutes, no problems.

So just submitted a returns request to ebuyer for a direct replacement.

Thanks for the assistance all.

 

[SieB]

Right then, so after a bit of swapping back and forth - looks like the problem is with one of the GPU's.

Just ran Tomb Raider on #2 for about 45 minutes, no problems.

So just submitted a returns request to ebuyer for a direct replacement.

Thanks for the assistance all.

No probs, hope you get it sorted.