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Thread: something's wrong. CPU or PSU? Should I look for a single rail?

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    Default something's wrong. CPU or PSU? Should I look for a single rail?

    Hello.

    This last week I've learned more about PSUs than in the whole 30 years before. Up to now, the PSU was just something you had to have, and if it was a brand name, it was better 'cause it was less likely to burn up and take half your PC's guts with it. Now ... I need help.

    Here's the problem:

    This works. Perfectly. Stable. Quiet. Cool. Turned me into a Vista supporter

    mobo: Gigabyte N650 (SLI-DS4L)
    CPU: Intel Core2 Duo E6400 (FSB 1066 on a FSB 1333 mobo)
    GPU: 1 Gigabyte 8800GT (GV-NX88T512HP) - factory overclocked
    RAM: 4x1GB OCZ Titanium DDR2 800
    HDD: 1xSATA 500GB, 1xIDE 300GB (both WD Caviars)
    DVD: LG supermulti, SATA.
    Fans: 2x120mm Arctic Cooling, one on SYS-FAN, one on a HDD molex, push-pulling front to back.
    CPU cooler Gigabyte Volar powered on CPU-FAN.

    All powered from a Gigabyte PSU that says: 400W total, 460W peak, 14A on the +12V CPU 4pin, 15A on the +12V PCI-E 6pin


    Last week, I got a nice discount on a Core2 Quad Q8200. I bought it.
    I was already worried about my theoretical power draw, so I've also bought a somewhat larger PSU to account for the extra ~70W of the Quad and to give me some breathing room. And because it was modular and I got fewer cables in the case, but that's just fancy.

    The new PSU is a CoolerMaster Real Power M620. Let me reiterate: this up from a PSU advertised as 400W. The CoolerMaster says it has three +12V rails, each one at 19A, for a total of 516W on +12V.

    I plugged in the Quad. Vista said I got a new CPU, I started the Windows Experience Index thing to see how much better the new one is, and the PC rebooted.

    Restarted in safe mode, took a look at Event Viewer, and it's empty except for "the previous shutdown was unexpected" and the warnings and errors of safe mode (DHCP and network related, mostly.)

    Restarted, back to normal mode. Aero was turned off. Looked at event viewer again. Empty. Read e-mail. Opened an excel. A webpage. Turned Aero back on ... hard restart.

    Removed the IDE HDD and the molex powered fan. Safe mode. Event Viewer. Nothing. Normal mode. Aero. Word. Excel. Outlook. SpeedFan. Chrome. TWO Word docs at once. The Experience Index completed successfully (5.9, yay!) NWN2 ... hard restart.

    To keep the story short: whenever I try to do something more intensive than normal office operation, the power shuts down. Not Vista. Not BSOD and soft reboot. The whole PC turns off as if I pulled the cord, and starts with the POST.

    I'm now writing this with the Duo and the M620. The PC is back to its old adorable self.

    So, please help! Would you look closer at the Quad? Do I need an even bigger PSU? Do I need a single rail (Corsair HX/TX)? Got any recommendations for ways of testing this?

    Oh, BTW, specifics: the manual of the M620 says that +12V1 goes to the 24pin and +12V2 goes to the CPU 8pin/4pin. Where's 12V3? Both PCI-E AND HDDs? They say "+12V" . But even so, the GPU worked on 15A with the Gigabyte, it should work with 19A now.

    Thank you.
    Mike.

    PS *waves at Burebista*
    Last edited by mishusas; 07-03-2009 at 05:34 AM.

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    Default

    2 things to check before anything else
    - did you make a BIOS reset after changing CPU's?
    - did you plug in 8 pin EPS12V instead 4 pin Auxiliary power? Just to be sure.

    LE: Oh s**t. Your CPU isn't supported by your MB.

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    Default

    Ah yes, planned obsolescence. Keep the microcode that tells the CPU how it works in the BIOS, so you can later just stop updating the BIOS and everyone has to buy a new board for a new CPU.

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    Default

    Quote Originally Posted by burebista View Post
    2 things to check before anything else
    - did you make a BIOS reset after changing CPU's?
    - did you plug in 8 pin EPS12V instead 4 pin Auxiliary power? Just to be sure.

    LE: Oh s**t. Your CPU isn't supported by your MB.
    - loaded fail-safe defaults, is that what you mean?
    - no, the difference is rather obvious.
    - the a****les! The box says "supports Core2 Quad" and "FSB1333 supported." Even the blurb on that page says "the GIGABYTE GA-N650SLI-DS4L features FSB1333 support for the record-setting Intel® Core™2 multi-core processors" but then in the list it's just two Quads at 1066, and four 1333s, all Duos.

    As the great revolutionary thinker Flava Flav used to say: "Don't believe the hype!"

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    Quote Originally Posted by burebista View Post
    LE: Oh s**t. Your CPU isn't supported by your MB.
    That's one distinct possibility, but I'd run something CPU-intensive like prim95/orthos to make sure. It's possible that the CPU isn't really hitting memory until you start up the graphics.

    The symptoms do match overcurrent protection kicking in, but I wouldn't think you'd be near those limits. I'd try a different PSU if you can borrow one, but I'd experiment a bit more before going and buying one.

    (It's also pretty easy to disable OCP if you're handy with a soldering iron. The clever way is to cut the shutdown signal from the overcurrent protection chip, but you can also just add a heavy wire jumper across the output current sensing shunts.

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    If you follow the link under "supported" it actually says that it's not supported Now, whether that means "they might work, but we won't swear on it," or "these two will never work together, we guarantee," that's another question ...

    Something CPU-but-not-GPU intensive: I have SIW. It has a BURN mode where it loads all cores at 100% and tries to keep them there to check the temperatures. I've done that with the quad. The PC did not shut down.

    As I said, with only one HDD, it's almost stable. It only dies when the GPU kicks in. Unfortunately, I can't borrow a bigger PSU. I do have a smaller GPU, though, a 7600GS with passive liquid cooling. That's what I will test this weekend.

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    Default

    Giving up on this.

    I've looked up some mobos ... G31 is older than n650 isn't it? And yet it works with 45nm quads. Black dot for nvidia
    Also, the price of a new mobo that works with everything I have does not justify the effort and the risk of trying to make these work. Whenever i need or feel like doing a reinstall, I'll switch mobos.

    Bottom line is that I've upgraded my PSU, I know that I have a very good PSU to fall back on, and I've learned not to rely too much on box blurbs.

    Props to Burebista for spotting the problem.

    Thanks.
    Mike out.

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