I7-2600k 4 cores in bios - 1 core/1 thread in windows

[jmpjmpjmp]

Help i just upgraded my pc and im stuck with quite an unusual problem.

After booting up on a fresh windows 7 install i noticed my i7-2600k was running only on 1core and 1 thread. cpu-z, Cinebench, 3DMark 2011 all recognize the CPU as 1 core/ 1 thread. And this is with 4 cores registered and all cores + multi threading enabled in bios.


It actually runs stable doing prime 95 for 15+ hours, so is this a faulty cpu or am i missing something???

Full spec:
Win 7 Home Premium 64bit
Asus p8z68-v Pro (bios 0606)
i7-2600k
1600mz vengeance 2x4gig
1kw toughpower psu
Twin Frozr Gtx 560 Ti
120GB SSD Corsair Force GT

I ran tests of all kind and everything seems perfect as is should be, beside my cores going bonkers.

 

[popatim]

hyperthreading would bring up the other 4 cores once he gets the real cores working. To set the # of real cores you need to set the "Active Processor Cores" to ALL. in the bios. Its right under Hyperthreading in your bios advanced section.

If those are already set properly then Win 7 has an option to select the number of cores to run.



msconfig> boot tab> advanced options>Number of processors should be unchecked
if it already is try checking it and selecting 8.

 

[jmpjmpjmp]

I have had all 4 cores enabled at all time in bios, i also have had hyperthreading enabled at all time.

I just reinstalled windows again, with no bios change compared to my first windows installation, but this time all 4 cores + hyperthreading is used in windows.

As my issue is solved now its great, but i still wonder how 2 identical windows installations can differentiate on cores found.