PSU upgrade for HD5770 CrossFire

[Pap1er]

Hello pals,
I decided to upgrade my single HD5770 system with another HD5770 and make crossfire system. I just need help with choosing right PSU for that configuration. Currently thers Corsair VX550W power supply in my PC. I tried to run some benchmarks and play few games with current PSU, but random crashes to desktop occured with "aplication XXX stoped working" error message. It seems to be weak PSU to feed both cards (correct me if I am wrong). I read on AMD site that recommended PSU for HD5770 CrossFire is 600W with 2x 6pin 75w connectors. I am not advanced user so i want to ask you for your opinion which PSU will be fine.

My PC configuration
CPU: AMD Phenom II 965 C3 @ 3816 MHz / 1,425v core
RAM: 4 x 2GB DDR2 Kingston HyperX 1066MHz
MB: GA-MA790X-UD3P
HDD: 2 x 500GB + 2 x 320 GB raid 0
VGA: ATi Radeon HD5770 Crossfire
Cooling: Corsair H50

 

[DarkOCean]

Corsair tx, hx650w ,tx 750 etc

 

[CDdude55]

A 550w PSU(especially from Corsair) should be more then enough to power two 5770's and the rest of that system with ease.

Also, i highly doubt those application crashes are coming from the PSU being weak.(if the hardware exceeds the PSU's limit by a high amount, it will just shut down, and not just give out app crashes)

Reinstall your video card drivers and bring that CPU back down to stock to see if that's the issue.

 

[musek]

I agree with CSdude55, PSU should be more than enough. Are you sure that both cards have 6pin power plugged?
Otherwise it's driver related.

 

[Pap1er]

A 550w PSU(especially from Corsair) should be more then enough to power two 5770's and the rest of that system with ease.

Also, i highly doubt those application crashes are coming from the PSU being weak.(if the hardware exceeds the PSU's limit by a high amount, it will just shut down, and not just give out app crashes)

Reinstall your video card drivers and bring that CPU back down to stock to see if that's the issue.

I tried to run CPU benchmark at default and oc frequency and it seems to be stable. Everest stability test was runing fine for almost 8 hours in both cases. I also reinstaled catalyst 10.8 but with no luck. Only thing i didnt try was reverting VGA driver to older version. (I´ll try this evening.)
Thank you for suggestion.

 

[Pap1er]

I agree with CSdude55, PSU should be more then enough. Are you sure that both cards have 6pin power plugged?
Otherwise it's driver related.

Yes I am sure that both 6 pin connectors are plugged into cards. Crashes seems to be total random, sometimes 1 minute after loading game, sometimes after 1 hour. Video playback runs fine without any problem.

 

[JrRacinFan]

Sounds more like a ram/northbridge related issue and not power supply. What stress testing utility did you run for 8hrs? Try out maybe OCCT Linpack and see what happens.

 

[CDdude55]

Yes I am sure that both 6 pin connectors are plugged into cards. Crashes seems to be total random, sometimes 1 minute after loading game, sometimes after 1 hour. Video playback runs fine without any problem.

Some other things you can do is run the system with one stick of RAM and just go down the line through each stick of RAM testing them and you could possibly find a defective one that could be causing the issues.(also try running Memtest)

And don't forget to try resetting CMOS.

 

[Pap1er]

Sounds more like a ram/northbridge related issue and not power supply. What stress testing utility did you run for 8hrs? Try out maybe OCCT Linpack and see what happens.

Everest Ultimate stability test

 

[Pap1er]

Some other things you can do is run the system with one stick of RAM and just go down the line through each stick of RAM testing them and you could possibly find a defective one that could be causing the issues.(also try running Memtest)

And don't forget to try resetting CMOS.

I dont think that memory is bad, cause Everest stability test stress also RAM, but I´ll try each stick independent as you suggested.

 

[JrRacinFan]

Everest Ultimate stability test

Here, run this ....
http://www.ocbase.com/perestroika_en/index.php?Download

 

[n-ster]

I can confirm you VX550 is enough for 5770 CF

 

[mastrdrver]

I'd be surprised if that Corsair couldn't run two 5770s. I've ran two 5870s and a 955BE off a Neo Power 650 with extra cables from a 550 version I have. I was trying to confirm a bad card only under DX11 mode.

From everything I could find an i7 920 overclocked with those card should be pushing the 625w threshold. With the 955, I expect a little less but not much but ran Vantage several times without problems.

Xbitlabs did some nice looks at power draw by all 5 series cards and most Fermi generation cards. They also covered the effects of overclocking with voltage increases. By looking through those I'd assume a 30 amp load which is what the 400w Corsair is rated for. Even if you allow for a couple more amps for variance, the 550vx should have no problem.

I would have to agree with others at this point that you just reset your overclock to stock. Save all your settings so you can restore them if everything turns out ok. Its just a simple check to make sure you can rule out your overclock for sure and then go on to the next thing if the problem still persists.

 

[Pap1er]

I have tried to set all overclocked parts of my PC to default (also tried to run Ram test with each stick independently+reset CMOS to dafault), but crash to desktop persist. Seems to be driver issue. I havent tried revert to older drivers yet, maybe later when i come back home from work. One card setup was never problem for me so i think it has to be crossfire issue itself.

Update: also few bsod crashes occures with unspecified error

 

[musek]

Make sure to follow this guide when reinstalling drivers.
Of course there is a possibility that your PSU can't handle this Crossfire setup, but this would only mean that there's something wrong with the PSU itself.

If changing drivers won't solve anything you could check on a different PSU. Just to be sure.

Good luck.

 

[Dent1]

I have to agree with the others here, your PSU can handle the HD 5770 in crossfire. I'm running the 4850 in CF and it uses more power than the 5770. My PSU is a crummy CoolerMaster 460W from 4 years ago. I've had no problems.

Your issue seems driver related than anything else. Remember to run a registry scanner like CCleaner before and after uninstalling ATI drivers.

It could also be a temp issue, crossfire is known for increasing the overall GPU temp and system temp.

 

[Pap1er]

Solved

So I have finally solved my problem. Problem was "memory" related if I can say it that way. It is strange but system was unable run stable in crossfire when memory is set to its default 1066MHZ. I had to lower memory frequency to 800Mhz and problem has gone. My research stopped at gigabyte motherboard because this board use to increase base CPU frequency from 200 to 202~204 even if I set manualy 200 in BIOS so memory was runing little over stock setting. I cant understand it well why this was problem bacause most systems can handle such a small bump. Most strange is that system was not able to handle it only with crossfire enabled. And more... I have played with overclocking and system is rock stable at 3.82GHz / CPU and 950MHz / RAM. Also no problem to push NB up to 2.6 GHz... And absolute sweetest thing is that Cool&Quiet is also working. (It was never working before when I changed CPU multiplier and base frequency) Now it runs like charm.

By the way, JrRacinFan thank you for great bench utility OCCP,