Core 2 Quad only running on 2 cores?

Hello all,

Well today I went down to my local microcenter to pick up a new CPU because my old E7400 was getting stale and boring, so I grabbed a Q9550.

Took the old one out and installed the new one easily. Starts up fine, but in Task Manager, Speedfan, and CPU-Z it only shows 2 cores (2 threads):


Gigabyte EP45-UD3P
Mushkin 8GB DDR2 800
Windows 7 Pro 64bit

So what the hell is the problem? My BIOS is up to date and this CPU is compatible with my mobo. I have tried changing the BIOS settings to default already.

What else should I do?
18 answers Last reply
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  1. Under my device manager it shows (under processors) that I have 4 cores though.

  2. This is a long shot since I can't see this being the problem. But go to Control Panel -> Administrative Tools -> System Configuration. Go to the Boot tab and click on the Advanced options button.

    In the dialog, there should be a checkbox for Number of processors, and a dropdown box underneath it. Usually the checkbox should be unchecked and the OS will use all available cores. Anyway, if that doesn't work, tick the checkbox and set the number of cores to 4, reboot and see what happens.
  3. Ok, so here's what happened.

    I went to where you told me to (I had a problem with this before with my C2D that was easily fixed like this). The drop down menu only showed selections for 1 or 2 cores, so I unchecked the box all together and restarted my computer. Then something odd happened. My Video drivers, for some reason, stopped working. So I went to the task manager, and 4 cores are now showing! Went back to the drop down menu, and the 1 2 3 and 4 core selections show now. So that actually worked, now I have to figure out why my video drivers stopped working.

    For the record, I am using 2 4870's crossfired.
  4. Just installed the new driver and it works fine, thanks for your help!
  5. Alright, huge problems are arising.............

    Right when I got all 4 of my CPU cores to show up, for some reason I had a problem with my video drivers. I figured updating the drivers would fix it, but I have ran into some huge, huge problems.

    First, after installing the drivers, the video showed up fine on my screen, but CCC wouldn't open, so I had to uninstall the drivers and CCC to get it back working. But then CCC wouldn't detect my second videocard. When I would go into device manager, it would show one videocard up to date, and the other had the yellow ! sign. It stated something about an error code 43. So I just uninstalled the driver for that, and restarted my computer. But now once it just goes past the "starting windows" splash screen, I get a BSOD STOP: 0x000000003b

    It won't make it passed that for some reason. I'm trying a startup repair right now, I'll post more later. Somebody have some suggestions for what might be the problem here though? (and how I can fix it). I have no clue why putting a new processor in my computer would cause such large Graphics Card issues.
  6. Sadly I'm at school and won't be able to do any troubleshooting until late tonight after work. My powersupply is a PC Power+Cooling 750W, which I believe should be enough to power everything. Should I maybe try taking out 2 sticks of RAM?
  7. were there any other or follow up error codes after 0x000000003b? apparently it's to do with a system service, but it's normally followed up by what type of system, ram etc. If I were you I'd remove the second GPU and restart. Then when it seems ok, install the second. It could also be what was suggested about your Bios.
  8. ...BSOD could be a driver issue. Could be PSU or RAM as well though...

    If you have the windows install disk, I'd just format at this point. Otherwise, clean out everything.
  9. Ugh, I have so many games I would need to reinstall though =(

    I actually fixed the BSOD problem late last night, just did a system restore. But one of my videocards will not work. I uninstalled and installed the drivers for it multiple times, yet one of them works fine and the other continues with this "Code 43" BS in Device manager.
  10. I had the same problem when I upgraded from a single-core processor to and AMD dual-core. I used a windows restore disk I created off of the computer when windows was installed with a single-core. Using this disk, doing a clean format still installed 3 ACPI files that was telling the machine that there was only one core on my processor. This is where your issue is as far as I know, going from a dual-core to quad-core. A clean format will be the best solution in your case, although it sounds like reinstalling will be time consuming.

    A google search will provide more information, I can't find the old thread on that I followed that helped me fix the same problem.
  11. Well, I just removed both cards and tried them solo. Both cards work perfectly fine. I really don't think that my PSU is maxed out, but then again it may be. I figured a 750W would give me plenty of head room.

    I'm going to try and remove 2/4 sticks of RAM and see if that frees up some PSU power.
  12. Its not your PSU i checked your specs that bad boy has 60 amps on the 12volt rail thats massive for one rail and has an 83% efficency rateing now as long as that PSU is running right there is noway its a power supply issue. My best guess is the combination of a new bios and a new processor threw windows off. Any major hardware upgrade should always be followed by a clean install of windows. If you can a good way to test before you do a clean install is make a partition and run a dual boot system and see if the fresh install helps if it does you know what you got to do.:)
  13. I really don't have anything super important on windows (that I can think of) other than my games. I use mostly steam so I guess a fresh install of Windows wouldn't be HORRIBLE. I just have a couple of problems, one being I cannot remember where my disks are, and what the code is. Is there any way (if i could find the disks) I could repair windows, so I don't have to reinstall everything?

    I also tried both cards in my second PCI slot, and they both worked.
  14. there are ways to get your product key. and all the other drivers can be downloaded i recomend doing that befor you do the clean install and putting them on a disk.
  15. Any one of these programs will work i have used the first one on the list before.
  16. AAAAAH, I fixed it.

    Probably something extremely obvious, but when I was messing with the "number of processors" selection in system configuration, I must have accidentally selected "PCI Lock".

    I deselected it and restarted Windows, and VIOLA! Both videocard fans spun up to the normal selection, the CrossfireX selection in CCC came back, and both GPUs are running like normal, with everything else running normal also (CPU overclocked, all 8 gigs of RAM in). Thanks for all of your help everybody!
  17. Now it also seems that replacing my CPU has fixed a year long problem I've been having with several games. Crysis, Red Faction: Guerrilla, and Bioshock 2 would always freeze my system whenever I tried to run them, but now that I have everything worked out, all of them install and run perfectly fine. Guess my CPU was the problem after all =D
  18. I am facing this weird problem right now.
    Here is the proof..
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