Bad z77 sabertooth or PSU?

[TheGabester]

Had a z77 Sabertooth for a few weeks, no issues at all. Then I added a few upgrades, put in a couple more sticks of RAM, no problems at all. Then added a couple of Samsung 830 SSDs and another 7870 to CF and was able to do a fresh install of Windows without a hitch. Once I got to the video drivers, it all went downhill.

Determined the second PCIe slot may be fried, single GPU on that slot won't work. Both GPUs worked on the first slot so it wasn't the GPUs. Did another fresh install with just one GPU and it worked without a hitch for a day.

Now today I restarted and it hangs on the black Windows loading screen for 30 or more seconds. At times where it didn't, windows would load in 10 seconds but none of my USB devices (keyboard and mouse included) would turn on for another 20 seconds.

So is my PSU going bad now, I already know the Mobo may be faulty with the second PCIe slot, but my PSU is about 2 1/2 years old and has been running nearly 24/7 since I've had it. Thing is I've disconnected all my HDDs and left two sticks of RAM and it did nothing to help. Thanks for reading.

Specs for reference:
MB: Asus z77 Sabertooth (updated to latest BIOS)
CPU: i5 3570k (OC'd to 4.2Ghz, watercooled with Corsair H50)
RAM: 4x4GB Corsair Vengeance 1600Mhz
SSD: 2x Samsung 830
HDD: 1TB Samsung / 320GB WD Scorpio Black (old laptop drive)
GPU: Radeon 7870 (XFX and Gigabyte, both work, can't crossfire)
PSU: Corsair TX750w

 

[inzone]

While you trying to start the Pc today you have one or two video cards in? I know you said that the second slot appears to be fried and the board does have another x16 size slot that is a x4 slot and a video card will fit in it and work but at a reduced performance so you could try the second video card in it just to see if it works. The reason being is if it doesn't work then you may have a corrupted bios file or chip and if you have dual bios on the board you can try switching to the other bios chip to see if you can get the Pc to turn on. I have had an issue similar to yours and thought the same thing , that the slot or even the video card was bad and it ended up being a defective bios chip which was replaced and then worked fine.

 

[jaquith]

PSU - maybe, the simplest test is to unplug the PSU for 10 minutes and then plug it back in and note the early behavior. In general, if that helps then quite often it's a sign of a failing capacitor issue of the PSU.

By my calculations your PSU is properly sized including 'electrolytic capacitor aging' but the CMPSU-750TX comes with a 5 year warranty. If needed Corsair offers 'cross-shipping' but you'll need your VISA and you can get an RMA by next week.

If needed I often recommend you breadboard and remove and rebuild the system outside its' case. I don't know what case you have but unless it has conventional standoff's you might have grounding short. Also only use the Intel Z77 SATA ports and try Disabling the ASMedia ports in the BIOS.

 

[TheGabester]

I reflashed my BIOS and that seemed to solve my booting issues with hanging at the Windows Starting screen, now it all works fine, but on a single GPU. Thanks Inzone!

Figured that was solved so I gave crossfire another shot and everything booted up fine. Played a game for a few minutes, then did a few restarts, no issues.

Went to OC back to 4.2Ghz from 3.8Ghz and upped my RAM back to 1600Mhz from 1333Mhz. Crashed on boot, lowered the OC to 4Ghz, booted but error popped in windows saying the drivers couldn't detect the card. Went down to 3.8, was able to boot but would crash in a game. Lowered RAM settings back to 1333Mhz, same issues even though these defaults worked a short time earlier.

Now I'm really leaning towards the PSU dying out, I mean if both cards work for even a few minutes in a game, it can't be the PCIe slot could it?

Also not sure if it could be the case shorting it, it's an Antec 900 and it's got those standoffs you can place where needed.

 

[jaquith]

If you're running AI Suite then my advice is to uninstall it and only manually tweak the BIOS. Also try MSCONFIG Diagnostic mode and stress test the GPU's without a CPU OC.

BIOS (basic settings):
Press (F5) ; Load Optimized Defaults
AI Overclock Tuner -> XMP / Profile 1
Press (F10) ; Save & Exit = Yes

Stress test.

If the BIOS for some reason is corrupt then my advice is to properly Clear CMOS; unplug the PSU for 5 minutes, move the CMOS Jumper for 5+ seconds and back to Default, plug the PSU in again and enter the BIOS 'basic settings' above. Nice generic video - http://www.youtube.com/watch?v=rdHH9KrceR0

 

[TheGabester]

If you're running AI Suite then my advice is to uninstall it and only manually tweak the BIOS. Also try MSCONFIG Diagnostic mode and stress test the GPU's without a CPU OC.

BIOS (basic settings):
Press (F5) ; Load Optimized Defaults
AI Overclock Tuner -> XMP / Profile 1
Press (F10) ; Save & Exit = Yes

Stress test.

If the BIOS for some reason is corrupt then my advice is to properly Clear CMOS; unplug the PSU for 5 minutes, move the CMOS Jumper for 5+ seconds and back to Default, plug the PSU in again and enter the BIOS 'basic settings' above. Nice generic video - http://www.youtube.com/watch?v=rdHH9KrceR0

Going to have to give that a shot tomorrow, it's running flawless with a single GPU at the moment so that'll do for now, been banging my head at this problem since Tuesday and I have to enjoy my Friday night. Thanks for the tips, I'll fill you in on the results tomorrow.

 

[jaquith]

You might want to also try a different CF Bridge...a bad bridge can cause problems. In general different brands of the same AMD or nVidia GPU 'should' work together unless one of them is an OC with a voltage modification. Anytime I run SLI/CF to eliminate any potential oddball issues I always use the exact same GPU's. (KISS) Keep It Simple, Stupid. You might be the exception with a mixing problem.

 

[TheGabester]

Ok I'm now pretty much sure it's either A) PSU getting old or B) Two different clocks from the video cards (1 Gigabyte 7870 at core 1100MHz and mem 1200Mhz and a XFX at 1050Mhz and 1250Mhz mem)

Did the cmos reset and tried with both cards, booted into windows and crashed when I set to crossfire. Reset and VGA red light lit on board with no display on POST. Reset again and it crashed at loading windows, fourth time it got in but the cards weren't detected properly in windows.

Took out the Gigabyte card from the top pcie slot that I've been using for the last month and left the new XFX card in the 2nd slot. Computer worked perfectly fine just like the other card in the top slot. Stress tested without issue so I'm certain the slot and card are fine. Also tried three different bridges to no success.

So now I'm down to tweaking clocks and voltages which I don't want to do yet since I'm afraid it'll void my warranty which I don't want to do in the first couple months of owning a new part. Or I'll wait to get a PSU in a few weeks, have to save up for a good one.

Would've followed the kiss rule, but I bought the gigabyte card first and hated it's size because it'll fit in my top slot but will block my intake fan on the bottom two slots. Then I saw a deal I couldn't pass up to get the XFX 7870 DD BE for $215 and never thought it would've been this much trouble to crossfire two different brands of the same model. Thanks for all the help and input so far jaquith, learned a lot from this experience so far.

 

[jaquith]

Well this may or may not work - i.e. you're a Guinea Pig

* Install both GPU's and CF bridge.
* Download and install MSI Afterburner - http://event.msi.com/vga/afterburner/download.htm
* For now set both cards to slowest of the two or 1050/1200 and press Apply.
* Test

MSI After burner will set both cards to match each other and might solve the problem, and the settings are safe to both cards.

 

[TheGabester]

Ok, just tried that out and set the settings to 1050/1200. Clicked on activate crossfire, crashed. Reboot failed on 1st try, got in on second and tried to activate crossfire again, this time windows stopped both devices, code 43 or something, rebooted again, crashed on boot.

Throwing in the towel, gonna spy some psu deals and hopefully get lucky the next few weeks. This ought to be the reason why it's not working. Surprised my TX750 couldn't pull it off, but then again it was a soldier for being on 24/7 for most of the past two years. I really can't think of anything else that may be wrong since the video cards work fine by themselves and on both PCIe slots.

EDIT: Just read in the manual for the mobo, asus recommends a 1000W PSU for crossfire with higher end cards (which I suppose the 7870 is). I'm guessing that going shorter than that, especially by 250w and more with cap degradation would probably cause issues

 

[inzone]

Back to an earlier post when you said that you reflashed the bios and it seemed to help your situation at that time but now your still having issues I' m starting to believe that you may have a bios issue. I can't believe that you need a 1000w psu to run Crossfire , I know you said that the manual said that but it seems a little high of a requirement.
Have you changed the bios version to either a newer or older version? I think that board has dual bios chips have you tried the other one?
I had a MB last year that drove me crazy with a similar problem and like you I thought it was the video cards , and then the powr supply , and then the motherboard and I could not get to the cause of the problem so I called the boards tech support and sent it in for repair. When I got it back there was no paperwork saying what was done and I had to call to find out if they even fixed it and they said that it was a defective bios chip which was replaced. Hooked it up and it ran fine with no issues at all.
So even though the computer is functioning you can still have a defective bios chip or a corrupted bios file.

 

[jaquith]

You can get any sized PSU you want, but even OC'ing the CPU & GPU's using CF 7970's an 850W is more than sufficient. Older prior gen GPU's yep were power hogs e.g. GTX 480's or HD 6970's. Proper size is 750W~800W for your setup ; PSU Calculator - http://www.thermaltake.outervision.com/Power

Running idle in CF you're drawing ~140W (or less) so if no load causes the BSOD only after the CF is Enabled screams the GPU's.

What typically happens with an undersized (good) PSU is extreme load either causes the PSU to drop or the system to throttle.

I know SeaSonic makes most of the HX & AX Corsair PSU's, and my HX850 has been known to go over 1100W i.e. beyond rated, the trouble you start to have is high levels of ripple.

 

[TheGabester]

@inzone - While reflashing did help resolve my booting issues with a single GPU, and even had crossfire working for a bit, the moment I went to BIOS to up my OC from defaults, stability went out the window. Even going back to the defaults that worked earlier didn't resolve it, so I'm left using a single GPU and everything works fine as before(even tested both cards individually on both slots). It came to no surprise as I've never been able to get crossfire to work without my system losing stability, only a few fluke boots where it worked for a bit, but rebooting was still hit or miss.

I'm using the latest BIOS and unfortunately don't have a dual BIOS to swap and check. I pray it's not the board since my luck with RMA'ing products has been less than subpar, I'll probably wait until after I get a new PSU and know for sure if it's that or the board. Knowing my luck, it'll be the board.

@jaquith - Just ran the calculator with 40% aging and it came out to 754w, 50% at 807w so I'm guessing my PSU is borderline. And yeah, after I activate crossfire, sometimes it worked, most of the time BSOD with a reboot that doesn't come back the first time and on the second, either one card or both would not be recognized by windows. So when you say it screams the GPUs, do you mean the GPU is faulty or that it's not getting enough juice to run?

Also could after activating crossfire, would that cause the BSOD on boot, because I noticed when it hangs at boot(on crossfire only), my keyboard and mouse would shut down for 10-20 seconds when loading windows and if they didn't power back on, windows didn't load.

 

[jaquith]

@jaquith - Just ran the calculator with 40% aging and it came out to 754w, 50% at 807w so I'm guessing my PSU is borderline. And yeah, after I activate crossfire, sometimes it worked, most of the time BSOD with a reboot that doesn't come back the first time and on the second, either one card or both would not be recognized by windows. So when you say it screams the GPUs, do you mean the GPU is faulty or that it's not getting enough juice to run?

Also could after activating crossfire, would that cause the BSOD on boot, because I noticed when it hangs at boot(on crossfire only), my keyboard and mouse would shut down for 10-20 seconds when loading windows and if they didn't power back on, windows didn't load.

If each GPU alone works fine then by itself it's not the GPU's (individually), but instead it's the mixing of two different GPU's (together) that's the problem i.e. Clocks.

Now often this isn't an issue particularly with 'reference' or best the 'same' GPU's, but in your situation of XFX + Gigabyte seems to be the issue. The solution is to get a 2nd matching XFX or Gigabyte GPU. If you cannot return one then eBay the other.

Regarding the PSU I' conservative and typically use 90%/90%, 30%, and enter my CPU OC to derive my choice of PSU's. Now 'if' I'm looking at Benchmarking then it's a lot more complicated 100%/100%, 30%, CPU OC, and determining the GPU(s) OC and subsequent OC wattage (100W~200W+ or higher per GPU). GPU OC'ing can be simple to extremely complex including hot-wiring and wattage is either best guessing or relying on LN2 data from others i.e. Forum data.

 

[TheGabester]

Alright, well looks like I won't know the problem until I either 1) Buy a second identical GPU, 2)Buy a new PSU, or 3)RMA the Mobo. Just wondering, if I were to successfully run the two cards running on a different motherboard (Crosshair IV with AMD 720), would that cross out 1 and 2? Was going to give that a try later on today.

 

[jaquith]

There are a lot of assumptions here, I am assuming your system is otherwise stable, BIOS has no corruption issues, no CPU pins issues, no CF bridge issues, etc and the problem is a software/hardware issue with the GPUs.

So with all of those assumptions then chances are it would be a MOBO issue over a PSU issue, and by no means is the PSU completely out of the picture under extreme load. Again, at idle the power requirements aren't too high -- and the simple Enabling of CF is causing a BSOD.

I further assume and would look at that the AMD Drivers are properly installed and there's no Defects in the CF Bridge. I'd try to boot into Safe Mode and install the AMD drivers plus try a different CF Bridge. CF Bridge - you only need (1) and chances are you should have at least (2).

Q - Have you tried each CF Bridge with the same results?
Q - Can you both boot into Safe Mode and Diagnostic Mode? ; if you cannot then you have an OS issue.

 

[TheGabester]

Q - Have you tried each CF Bridge with the same results?

Tried four different bridges. Also my card only has one slot to connect a bridge.

Q - Can you both boot into Safe Mode and Diagnostic Mode? ; if you cannot then you have an OS issue.

Was able to boot into it after a few tries, both cards showed up. Restarted back to regular boot and everything loaded with crossfire enabled. Started a game, instant black screen and crash. I've reinstalled windows twice already, second time with a secure erase and have had the same results so I doubt it's the OS.

 

[jaquith]

Again, then more than likely the GPU mixing. You might want to contact Gigabyte or XFX to see if they can offer any wizardry to this issue.

If you hadn't already tried reversing the GPUs then it also at this point worth trying.

(top)
Gigabyte
[CF]
XFX

and

(top)
XFX
[CF]
Gigabyte

 

[TheGabester]

Yeah, I've tried both of the combinations. Now I'm starting to lean towards it being different cards especially after reading another post where someone was having almost the same issues trying to crossfire an xfx 7970 and msi 7970.

 

[TheGabester]

Just an update, got a new seasonic x750 psu and still no dice so I can cross off power supply from the problem. Now to test it out on a different motherboard and I'll know for certain if it's the mixing of the cards or the motherboard itself.