System feels very slow after overclock

[Mach60KAS]

After overclocking my i7-920 from 2.67 GHz to 3.8 GHz, I've noticed that my system has become extremely unresponsive; particularly when trying to access the HDD it would seem. My system specs are:

CPU - Intel i7-920 (Bloomfield)
Motherboard - Asus P6T
RAM - Corsair XMS3 (3x2GB)
Heatsink - Thermalright Ultra-120 extreme
HDD - WD Caviar Black 1 TB and 2 TB, 7200 RPM
Gfx Card - Nvidia GTX 570

BClk is at 190 MHz, with a 20x Multiplier and VCore at 1.2875V. It's stable in memtest86 and in prime95 for in excess of an hour. Any idea what could possibly be causing this? It's certainly worrying when an OC causes your PC to slow down...

 

[abbadon_34]

it complete possible if overclocked incorrectly . easiest solution is to set it back to stock , good chance it's something else

 

[Mach60KAS]

I'll take some pics of the BIOS settings when I get home to see if there's anything immediately obvious to you. Could I have possibly set a voltage too low?

 

[abbadon_34]

let not get ahead of ourselves and waste time and effect, just save your settings or write them down, the restore the defaults. see if there is a difference. use you comp for a meaningful amont a time doing what you do.

 

[DarkSable]

Sounds to me like you pushed the OC too far for the heatsink, the chip is overheating, and because of that, downclocking a fair ways.

 

[Mach60KAS]

Sounds to me like you pushed the OC too far for the heatsink, the chip is overheating, and because of that, downclocking a fair ways.

I was seeing temps up to about 86 degrees C running Prime95 (blend) last night. Is this hot enough for the CPU to throttle?

 

[Mach60KAS]

Done some benchmarking using 3DMark 06, Vantage and 11; in all 3 cases the observed CPU scores were considerably higher than those at stock (e.g. 20826 vs 15695 in Vantage) - ruling out the clock speed being lowered or throttled due to temperature.

Interestingly, the hard drive read and write speeds were virtually identical between stock and OC, yet accessing the hard drive with OC frequencies runs like molasses. Are there any voltages or speeds which could be having a knock-on effect to SATA or the HDD controller?

EDIT: Putting the system back to stock frequencies causes everything to load at the correct pace, however I'd like to find a way to keep my overclock and get everything to load at a sane rate.

 

[Mach60KAS]

Does anyone know why this might be the case?

 

[abbadon_34]

start with a simple overclock, sticking to multiplier and core voltage. see where that gets you what happens. then slowly expand to other areas, which are most like to screw things up if set wrong.

 

[Mach60KAS]

I'm reseating my heatsink with Prolimatech PK-1 tomorrow night as well as an extra fan; should cut down the temps and hopefully stabilise the overclock.

 

[abbadon_34]

definately can't hurt

 

[Mach60KAS]

Reseated the heatsink, still getting really slow HDD speeds - though I've observed them at stock a few times now, too.

 

[tater5761]

Yes 86c is far too hot. That would be your issue.