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Psu not enough for overclock?

Discussion in 'Graphics Cards' started by Relinquish, Feb 20, 2011.

  1. Relinquish New Member

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    Would blue screening while stability testing be because of a PSU's inability to supply the card with powa?

    I've got a pair of watercooled GTX 460s in Sli connected to a XFX 650w XXX Psu. At certain speeds instead of artifacting the machine will simply blue screen no matter the voltage, I'd accept if the machine artifacted but a blue screen?

    And its not really even a blue screen, when it happens the screen goes black and then the PC re-boots, though no PSU shut down (Guessing this PSU works differently to others). After its not just a case of boot back into windows and off you go to play with more settings but if you turn on the machine or let it re-boot theres no video. So what I do to get round this is turn the machine off, remove SLi bridge, turn on. Then turn off as theres no image, re-install Sli bridge and then turn on and I can use the machine:banghead:

    Could this possibly be a motherboard problem?

    My specs are on the right <----
  2. mstenholm

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    Are you sure that it is you GPU's/PSU that are the culpit? 650 good watts should be enough for GPUs: 2*175, CPU: 150 W and others: 50 W. What I mean can you stress your CPU for hours without blue screen?
    Crunching for Team TPU
  3. HalfAHertz

    HalfAHertz

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    He has heavily over clocked and overvolted his system. I bet that just the CPU is pulling well over 200W. The Pii's are hungry mofos once you go over 1,4v. I don't remember XFX making very reliable PSUs so I wouldn't be surprised if it's the culprit.
  4. Bo$$

    Bo$$ Lab Extraordinaire

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    they are rebadged seasonic units, very well made and should EASILY take the load
  5. Bo$$

    Bo$$ Lab Extraordinaire

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    try removing overclocks and see if it still crashes
  6. Relinquish New Member

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    Right I'm gonna reply one at a time;

    Yes I can OCCT my CPU without blue screen (Prime 95 doesn't work with my motherboard:mad:).

    Lol I didn't realise it would pull that kinda watts, HwMonitor says 125w for my CPU clock. Also as someone has said here these are
    Stock isn't a problem (800/200/0.987mV) and my known stable air overclock is fine (871/2098/1062mV) but after that its besides me.:shadedshu

    Temps in games are around ~ 40c and in furmark ~ 50c which are a lot better than air but whats holding me back on the temp side is my pump. Other than that I've got full cover blocks and 2 * 360 rads. Never the less I don't see temps being the culprit and no I'm not 100% sure that my PSU is the problem thats why I'm asking :D
  7. Bo$$

    Bo$$ Lab Extraordinaire

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    Check the VRM cooling on the waterblocks (thicker pads???) that is a common issue with overheating RAM/VRMS
  8. Beertintedgoggles

    Beertintedgoggles

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    Usually when I've had issues with not enough power from the PSU the system suddenly powers off, no blue screen or warning of any type.
  9. Relinquish New Member

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    Hmm:wtf: I should know my self I've had a faulty non-name PSU do that on me.

    I've re-applied the thermal paste on the first GPU yesterday as I didn't do it right first time and the vrm heatpads were making, shall we say, very good contact:rockout:

    I'm starting to lean towards the motherboard now, anyone? Not that it doesn't work but is restricting my overclock? What about afterburner, should I try a newer version?
    Last edited: Feb 20, 2011
  10. Beertintedgoggles

    Beertintedgoggles

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    Can you check how hot the mosfets are on the motherboard (either by software or the old fashion finger trick, just don't burn yourself)?
  11. cdawall where the hell are my stars

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    doubt its the PSU sounds like a driver/vga card issue
  12. Hms1193

    Hms1193 New Member

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    My friend had a similar rig with SLI'd Sparkle 460 Calibre's and Silverstone Zeus 650W PSU. He was getting random Bsod's after OCing his PC. Switched to a 850W and no more Errors/Bsods.

    Don't know about the quality of XFX PSU's so not really sure if it's a PSU problem on your side but you can check another PSU on your PC to confirm that.
  13. Mussels

    Mussels Moderprator Staff Member

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    just because he has a seasonic made unit doesnt mean it cant weaken over time or be failing.


    OP made assumptions in the first post, which i think is misleading people.


    black screen and sudden restart? sounds like a PSU OCP event to me. anyone who went thinking BSOD, went off on the wrong track there immediately.



    Or that could be "it wont boot until i leave it powered off at the wall for X amount of time" - and THAT is a symptom of a PSU problem (overheating, tripped a resettable fuse in the OCP) and would perfectly fit with his assesment of PSU being insufficient.
    Relinquish, Bo$$ and random say thanks.
  14. Relinquish New Member

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    Ok then, well that sorts that dilema. What would you guys recommend for ~£100? I've got these three that I'm looking at now;

    Coolermaster Silent Pro Gold 800W Modular PSU | Eb...
    Corsair 850W TX Series PSU - 140mm Fan - 5 Year Wa...
    Coolermaster Silent Pro 850W Modular PSU | Ebuyer....
    http://www.overclockers.co.uk/showproduct.php?prodid=CA-150-AN&groupid=701&catid=123&subcat=
    http://www.overclockers.co.uk/showproduct.php?prodid=CA-041-AK&groupid=701&catid=123&subcat=
    :confused:
  15. HossHuge

    HossHuge

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    I just had the same kinda problem with my rig. I had a AMD PII O/Ced, HD6850 O/Ced and a 9800gt Low power for physx all going with a 500w power. About 10mins into Batman it would bluescreen. I tried no O/C on the HD6850 and it ran for about 15 mins. Next, no O/C on the CPU, about 20 mins.

    Then I took out the 9800gt and then everything was money. So, I guess you need more power.
    Relinquish says thanks.
  16. Relinquish New Member

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    Woahhhh, holy mother of power! LOlz, I just did a worst case scenario of what my PC could consume @ 100% ~ 756w of lovely power and I'm here rockin a 650w probably at its upper limit:laugh: Really I shouldn't be laughing but what can you do?:toast:

    Done some reading and am going to go for this Coolermaster Silent Pro 850W Modular PSU | Ebuyer.... right after I raid the couch for some coins:p
  17. Mussels

    Mussels Moderprator Staff Member

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    if you used one of those power consumption websites which tell you the load, they're always way too high. they rate my system about 200W higher than it really is.


    i'll read your specs and edit in a more accurate value once i do some thinkin


    edit: about 360W before your CPU comes into it. dont know the specs on it very well, but your maximum power would be about 500-530W at most. yes, that accounts for 460 SLI.

    i can certainly imagine that could push cheaper PSU's over their limits, especially since the 460's draw a chunk of that power from the PCI-E slots (and therefore, the main 24 pin ATX power connector)


    whatever PSU you go for, make sure its got a decent 12V rail - doesnt matter if its split or not, just make sure that first rail has a decent amperage on it.
    Relinquish says thanks.
  18. Relinquish New Member

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    That cooler master 850w has 66a on the 12v rail (single) . Watts = Amps x Voltage; 66*12=794w so that should be good enough right?

    Also if we take a 550 watt load on the PSu that equals to in a percentage: 65 % load which I'm told is ideal for where it should be working and to allow room in the future.

    Thanks :respect:
  19. Mussels

    Mussels Moderprator Staff Member

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    i've said before i dislike the coolermaster branded PSU's, but YES, 66A on the 12V should have much room to spare on your system.



    the 'peak' zone for PSU's is half crap, half irrelevant.
    When dealing with decent PSU's, the difference between their worst and their best efficiency is usually less than 5%. you also cant really make your system sit in that peak zone with any ease, since the video cards swap between idle and load, your CPU has power saving features, etc...


    get a PSU that can run your system stable for a long time, and the rest doesn't matter.
  20. Relinquish New Member

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    Lol.Ok so I believe I've found the problem, like we've established its the PSU. I bought a chepo wattage meter, pluged it in and found this:

    3.5w-4.4w Standby
    180w Idle/desktop
    190w Music/Desktop
    250w Music/Browser/HD vids
    400-430 Battlefield: Badcompany 2
    490w Unigine heaven
    :eek:580-598w Furmark:eek:

    All this with the GTX 460s @ 871mhz

    Thats some serious power used by furmark. Do you think if I can get stable in Unigine at higher clocks that I shouldn't worry about Furmark?
  21. cdawall where the hell are my stars

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    assuming 80% efficiency on your XFX thats only 470w i think you have plenty of room
  22. Relinquish New Member

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    Wait what. I dont understand, this efficiency thing must work differently to what I previously thought.
  23. cdawall where the hell are my stars

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    a 650w PSU@full 650 load will draw ~800w from the wall.
    Relinquish says thanks.
  24. Relinquish New Member

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    So what next, RMA for zie PSU?

    The call centre for RMA closes in 40 mins
  25. cdawall where the hell are my stars

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    for what its working just fine?

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