Overclock instability with external hard drives attached during boot.

[dcx_badass]

Ok, I've asked on other sites but we couldn't figure it. My overclock is unstable if I boot with my USB external hard drive attached. Ok, now you'd think, easy not enough power to the southbridge, now I've not tried incrasing this as I'm wary of playing with the voltages when I don't really understand it. What makes me think this is not the problem though is a few things:
± It only causes a reboot and the overclock to reset from a cold boot with a usb hard drive connected
± without a usb HDD connected it boots fine

What does that prove you are thinking, well

Once booted I can connect two or three USB external hard drives, my iPods (Classic 3G and touch), and my phone, and it's fine the overclock is rock solid 24/7, I can put the PC to sleep and resume with not a single problem, it only does it if they are connected during a cold boot. Now the fact that it works fine as long as I connect them after it's booted up and still fine regardless of going to sleep/waking up this suggests to me it is not a power issue with the southbridge etc. I've also seen that other people have had the same thing with Gigabyte boards and USB devices, anyway it's got me confused, the temperatures are great, under 40-42°c on full load at 3.55ghz.
I've attached a CPU-Z report as my sig, but a quick summary of my specs aswell:
Pentium Dual Core E6500 2.93ghz @ 3.55ghz
4GB ram, 4* 1GB sticks, matched pairs, 2 patriot, 2 kingston, 667mhz, running at ~800mhz with the OC
Motherboard: Gigabyte GA-X48-DS4
PSU OCZ StealthXstream 600w
GPU: EVGA 8800GT 512mb.

http://valid.canardpc.com/show_oc.php?id=1345124



Thanks.

[Dark Mantis]

Hi

Are you attaching the hard drive via a hub or directly ?

If directly, to a USB2 or USB3 port ?

[dcx_badass]

Directly to a USB 2 port on the back of the motherboard.

[Dark Mantis]

Is the hard drive you are having trouble with powered from it's own external supply or is it reliant on the USB for power ?

[dcx_badass]

Own power supply, I have three externals, two are identical and one is different, all mains powered, I've only tried the two identical ones, I'll test the third different one and report back in about 20 minutes.


*edit* Sorry bit busy, will have to do it at about 5pm.

[dcx_badass]

Yeah it's doing it with any usb  hdd attached, but as I say once booted I can connect all 3 and its 100% stable etc.

[Dark Mantis]

I think the only solution would be to increase the southbridge voltage a touch. I can see no other reason for this to occur as it does.