My +12v rail reads as being over 12v. Depending on which software I use,MBM5 and speedfan read it as 12.52v and corecenter(mobo's default software) reads it as 12.26v.Not sure who is most accurate? My PSU has adjustable rails,would it be best to get the output as near to 12v as possible? I'm not sure if I could read the output in the bios?Will check. Tt Lanfire MSI K8N Diamond AMD64 3000+'Venice' 1gb pc4400 OCZ Powerstream 520w 6600GT WDCaviar 160gb sata x2 ;~}

Your Power Supply wil almost never run at exactly 12V. In my experience it will run anywhere in between 11.8 - 12.4 depending on how good the power supply is. If you can, adjust it so it is as close as possible. Matt www.bbcomputing.co.uk matt@bbcomputing.co.uk

Since the DC isn't pure DC but a rectified AC wave, the readings can be different depending on the method used to measure it. But yeah, if you can adjust the voltage get as close to rated but not below. Use a good voltmeter and not any onboard measuring utilities. The power supply isn't perfect. The voltage will probably drop as you add more devices. So make the measurements with all the drives connected.

Just be careful because too much voltage may damage your devices. It happened to me on an old 250W PSU on an original Pentium2 350MHz Slot1 system. After upgrading to a Celeron 733@1232MHz after a couple of weeks I first lost my scanner (old tamarack model with ISA SCSI controller card) then my grapic card started to act strangely and finally an old 2,5GB harddrive was gone. Only then I realised that my PSU send quite a bit more power than needed into the system. I was very lucky because after installing a new 350W PSU my harddrive just returned, the graphic card worked again (I had some trouble after a new Windows installation on that system but the card still works well on other boards - no idea what's the reason!) and an uncle who is a rewtired TV technician was able to replace the fried transistor on my scanner controllercard!!!! But up to around 12,5V on the 12V line shouldn't be dangerous at the moment!