I recently rebuilt my machine to a i7 2600K, 8Gb Corsair Vengeance LP, Asus P8Z68-V PRO, MSI Geforce GTX560, and Be Quitet Dark Rock Advanced cooler. I kept my trusty Corsair HX520W PSU and 640Gb Western Digital Caviar Black Sata II HDD, mainly since HDD prices have gone nuts, so won't buy a new one till prices come back to reality. I've installed my Windows 7 64 bit OS without issue. however on booting from cold, usually my machine will startup then restart after about 5-10 secs, theres no beeps other than the single boot beep and no error messages. This seems odd as I just rebuilt my mates machine with a gigabyte board and he has no such issue. I'm wondering if this is just an Asus problem, I went into my bios and altered some settings (locked the memory to 1600Mhz) to see if that worked and i'm still not sure that messing around in there is the solution or if the board is faulty. I've read that setting XMP is the best solution but am asking for advice here in case anyone has a better solution. Any help is appreciated.
Aye, mine does it on the odd occasion and I still haven't figured out why. The settings appear okay from what I can tell.
In my experience ASUS bios can be a touch quirky... for example: My P5K wouldn't boot with my external HDD hooked up, unplug it and it's boot fine, hell it would boot from it... provided you plugged it in *after* you tuned it on... My P6T, when overclocked, would sometimes completely refuse to acknowledge my keyboards existence [it was fine once it got to windows though] Both would occasionally boot with a black screen [sometimes the "overclock failed!" message, even at stock speeds]... hit reset and it'd [usually] be fine...
I have seen someone post a video, it looks like the splash screen goes up, is interupted and then goes up again. If this is what you are experiencing I get this all the time too, I do not think the computer is restarting I think after it checks the main bios, the splash screen interrupts, then you see it checking the marvell bios then boots. I do think it is all part of the standard post, just that the splash screen goes up a few times makes it look a bit weird, if you are not using the marvell controller you can switch it off to speed this up.
It's definitely restarting as my 2 UV cathode lights and all fans cease working, then it comes on again. It's as if the machine needs to warm up the capacitors before booting correctly. It's certainly not the PSU as my machine never pulls more than 300W I know this as I have a meter sitting between the plug and the socket. I'm thinking that the boards own overclock maybe slightly unstable when booting from cold. When I enabled turbo mode the board already overclocked the CPU itself to 4.4Ghz without me doing anything, normal trubo mode for a 2600K is supposed to be 3.8Ghz Might have to do some further reading on what to tinker with and make it stable. Although this seems odd as the computer once booted it perfectly stable and ridiculously fast in any games.
Thats odd, if the lights go out sounds like it is restarting. Since you report you are overclocked with issues only from cold boot, once it is booted have you tried stress testing the system for stability at load too? On boot you might be pulling in excess of 300W peak, I would say that if your system is stable pulling peak power during a stress test, then it should be stable during post too. Also try booting with the overclock off, it could be the overclock needs tweaking and is unstable.
Did you flick the TPU switch accidentally? Or use OC Tuner in the BIOS? That'll do the overclock. It's probably not able to run at that speed from cold or it's a 'feature' of the auto-OC software maybe? Sounds like something needs warming up frankly, maybe your PSU caps are getting old and not holding the charge that they used to, or the initial current draw is causing an issue until the components warm up a bit.
Sorted it out. Entered Bios ->Advanced Mode ->Ai Tweaker ->Ai Overclock Tuner and set to X.M.P. This has reduced the overclock slightly, now running at a stable 4.3Ghz and booting first time every time. I'm thinking that the OC was upping the memory frequency which the mem modules weren't happy about and causing a reboot. Completely stable now and very cool. Cheers for the help guys
