Windows 7 Forums
Welcome to Windows 7 Forums. Our forum is dedicated to helping you find support and solutions for any problems regarding your Windows 7 PC be it Dell, HP, Acer, Asus or a custom build. We also provide an extensive Windows 7 tutorial section that covers a wide range of tips and tricks.

Windows 7: Locking up computer - CPU Vcore experiencing massive fluctuation(33%)

16 Sep 2011   #1

Windows 7 Ultimate x64
Locking up computer - CPU Vcore experiencing massive fluctuation(33%)

Hey guys,
I'm currently attempting to fix a locking issue with my newly built computer.

First and foremost I will describe the problem:
- Once every 12-72 hours my computer will lock up, displaying a frozen frame of whatever was last on the monitor.
- The lockups occur randomly; sometimes when nothing is running at all but the OS.
- All functionality is gone.
- Case fans, CPU fan, GPU fan, and mobo are all still powered.
- Computer is still generating heat (overall; haven't been able to tell part by part)
- Anything in a USB slot can still receive power. However anything new plugged into USB cannot.
- I've unplugged the DVI from the video card and plugged it back in a few minutes later, only to see the same frozen frame of my desktop (in this case, Breaking Bad in full screen).
- The only resolution is to hold down the power and restart, then all is fine for 1/2 a day to 3 days.
- On top of this, my direct replacement warranty expires in 4 days.

My specs are as follows:
Intel i7-2600k (CPU)
Zotac GTX 580 (VGA)
G.Skill 8GB 1600mhz Sniper (RAM)
Intel 510 120gb (SSD/BOOT)
Samsung 1TB HE103SJ (HDD)
Cooler Master Hyper 212 (COOL)

Potential culprit 1
- I'm getting an odd voltage reading using my NZXT 1000W PSU. Massive fluctuations. Using Speedfan and HW monitor, the "Vcore" voltages are flying about everywhere. My ASUS board features an "EZ overclock" button in this BIOS so I thought this might be it, but set back to stock the problem still persists.

Overclocked to 4.5ghz:

Stock at 3.5ghz

I should comment, in the ASUS UEFI (BIOS) window, it doesn't show the voltages fluctuating by more than a couple %. I'm not sure how that fits into the picture here. I do however feel this is the likely culprit to my freezing issue.

Potential culprit 2
The Intel SSD, since SSDs in general simply aren't that reliable (even Intel has close to 10% RMA in first year). It does figure out pretty nicely. I can't physically do anything because I'm not longer connected to a drive containing an OS, letting alone drivers for anything connected. The last image could be stored in RAM, hence why I can still see the last frame when unplug my DVI and plugging it back in. Not sure how it would explain the USB fiasco though.

Potential culprit 3
My video card (Zotac NVIDIA GTX 580). Even though I unplugged the DVI and plugged it back in, only to receive a signal, it could be that the card had that stored in it's RAM. There is nothing that points me in this direction however through testing, is it does above with the CPU/PSU.

Potential culprit 4
My RAM, simply because many people report that locking up is commonly a RAM problem. However I do not quite understand how to use MemTest x64. Is there a simpler program I can use for the same result, preferably through the OS? That or maybe a link on how I can get it to boot off a thumb drive. Thanks in advance.

So there we have it, I know it's a lot to read but I figured I'd be thorough as to not waste anyone's time with back and forths needed to attain info. I am open to suggestions on how to solve this problem as I really am not that savvy when it comes to building or repairing computers. I'm stumped and in dire need to solve this within 4 days, so I can return any faulty parts for direct exchange.

Thank you so much for your time if you have made it this far.

I appreciate any and all help!

My System SpecsSystem Spec
16 Sep 2011   #2

Windows 10 Pro/ Windows 10 Pro Insider

Statistically, Intel is the most reliable SSD. To eliminate that possibility, you could clone your OS to a mechanical hard drive and see if that resolves the problem. There is a ram test built into Windows 7, however it is not as reliable as memtest86. I would recommend you to use memtest86. If you want to eliminate the video card, remove it and use the on board video. But, that will relieve some of the stress on the PSU. If the PSU is not putting out enough voltage to run everything, relieving the stress could make it work OK and make you think it was the video card. Perhaps you could borrow a PSU from someone just to test that.

EDIT: given your situation, I don't believe you can test all of the components properly in 4 days.
My System SpecsSystem Spec
16 Sep 2011   #3

Windows 10 Pro/ Windows 10 Pro Insider

In looking at your images, Speedfan is not reading your PSU correctly. It appears to be reading your +12V at 6.8V. If that were true, your computer would not boot.
My System SpecsSystem Spec

16 Sep 2011   #4

Windows 7 Ultimate x64

I checked out the voltages in BIOS and guess what? RAM was set to 1.65V. It is rated at 1.5V as per the label on the RAM sticks. Would this be enough to have caused the issue? I also changed the Vcore from offset to manual (using recommended voltage of 1.31V when OC'd to 4.5ghz) and the whole Vcore voltage jumping around problem went away. It seems it's meant to do that, adapting power based on processor needs I suppose. Do you know if either setting (offset or manual) would be okay for now if I'm just trying to troubleshoot this issue? I'm also not sure what you mean by clone my OS. Do you mean just install it on a different drive or...? Thanks for the reply btw, really appreciate it.
My System SpecsSystem Spec
16 Sep 2011   #5

Windows 10 Pro/ Windows 10 Pro Insider

A clone is a 1-1 transfer of the OS. It can be done with several free programs, or you could image your ssd and restore it to a mechanical hard drive, or as you say just do a clean install for a few days.

The voltage is supposed to fluctuate some. Intel speedstep wil downclock the CPU to 1.6 and .09 -1.0V at idol no matter what your OC is. Unless you set the bios to manual. With setting it at manual the CPU will still downclock to 1.6 at idol, but the voltage will not drop, it will stay at what you set it at. That will cause you to use more power and create more heat. If it were me, I would set everything at optimized defaults then only change what is necessary. Set the dram voltage at 1.5 and set your sata controllers at ahci I assume, whatever you had them set to. You have to get the system stable at default settings before you try to OC.
My System SpecsSystem Spec
16 Sep 2011   #6

Windows 7 x64 Ultimate

Ack, I've had HORRIBLE experiences with the "Auto Overclock" features Turn it all off and leave it off.

Set everything back to normal with the auto overclocking option(s) off and give it a try, then you can manually overclock as you wish, but the auto stuff is just death...

[Edit] I should say that I meant the motherboard specific auto overclocking features (if that is what you were talking about). The standard intel chipset auto V/Clock features have been perfectly stable for me. Some motheboards try to add to that and that's what is full of fail.

As essenbe said, put everything to optimised defaults first and try that...[/edit]

P.S. If your HD light comes on and stays lit during the lockup, you can try turning off "Native Command Queueing" on the SATA interface (in the hardware manager) for the one port that the SSD is connected too. It's a feature for spinning drives that in some systems (my old one but not my new one) can cause the HD drivers to lock up when using an SSD. In fact when I disabled it, not only did the lockups go away but I got more speed out of the SSD as well.
My System SpecsSystem Spec
17 Sep 2011   #7

Windows 7 Ultimate x64

Thanks for the help so far guys. A few updates and questions.

1) The computer locked up again today. It was overclocked and experienced the same problem as usual, however the RAM was set to proper voltage and timing. Event viewer shows nothing relevant. This time however something odd happened. After I reset the UEFI back to "optimal default" setting my computer would not post. It reset itself (even the PSU turned off) 3-4 times within 20 seconds, then posted. This happened twice before, when I first built the computer and a few days ago. It looked like the LED light was on the graphics card when it would not post this time, right before it would restart. Last time however it was on the RAM (voltages were set too high back then though). Does this recent restart suggest a PSU problem or a VGA problem (if any)?

2) I'm a little confused as to how to reset my components to true stock settings. The only option I can find in the UEFI is "reset to optimal defaults" which doesn't seem right. Maybe I'm missing something.

Here are the options I have to work with using the P8Z68V-Pro:
8:06 shows the UEFI option I have with the board
13:45 shows the OS options I have with the board

Is there a way I can as well access normal BIOS or would this suffice?

3) As of now I have done the following changes since the last lock up:
- Reset back to "optimal defaults" in the UEFI.
- Set RAM back to 1.5V after reset
- Tested my RAM twice in MemTest and passed both times.
- Disabled the TPU and EPU switches on my mobo (TPU is auto-overclock, EPU is for power saving).
- Disabled Turbo Mode
- Set Duty Control to "Extreme"
- Disabled "C3 and C6 reporting to OS" in the "CPU" tab in the Advanced section of the UEFI
Are there any other changes I should be considering before putting it through the next "test run"?

4) Do SSDs get hot on the outside casing? I did not check for heat on there. If it cools down after a lock up would that make it a suspect?

- EDIT: I should note: Two lock ups ago, I was checking my temperatures in various sensing programs and the GPU was stagnant at 59 degrees celcius despite having no load. No matter what I would run (or lack there of), it wouldn't budge more than hitting 60 for a few seconds here and there. 30 minutes later the computer locked up while playing Oblivion.
My System SpecsSystem Spec
17 Sep 2011   #8

Windows 10 Pro/ Windows 10 Pro Insider

Here is what I suggest. Set the bios to oprtimized defaults, set the dram voltage, timings and frequency at whatever the sticks are. Storage controllers should be set to whatever they were on install. With an SSD I would assume it was ahci. Save and exit. If it boots into windows, monitor CPU and GPU temps and run it just like that. The idol temps of the GPU seems high to me, but not to the point of dangerous. Some GPU's run hotter than others. Run it like that for a while and see if you ger any lockups. I noticed you said it was overclocked. Do not overclock it. leave it running at defaults until we get it stable. Before you can think about overclocking, the computer must be stable at stock. Overclocking leads to instability, so you have to have a perfectly stable platform at stock before you try to overclock.
My System SpecsSystem Spec
17 Sep 2011   #9

Windows 7 Ultimate x64

Okay thanks. I have reset to optimal defaults and set the RAM. I was told to disable the following items however:
Here is what I have disabled so far after resetting to optimal defaults:
- TPU switch on mobo (for auto-overclocking)
- EPU switch on mobo (for power saving)
- Turbo mode (UEFI)
- CPU C3 and C6 reporting to OS (UEFI; I'm in offset mode +)
- CPU Speed spectrum
- Change duty Control/Line-In Calibration up to Extreme/Ultra High respectively as well
- Intel Speedstep

What do you think?
My System SpecsSystem Spec
17 Sep 2011   #10

Windows 10 Pro/ Windows 10 Pro Insider

I'm not familar with Asus BIoS settings, but Intel Speedstep is a good thing, the C states have to do with sleep. turbo mode is what you bought the K chip for, even the non K chips use that. I don't have the same settings for load line calibration, but as I understand it, on Asus boards that is the setting you use for high overclocks.

Who told you to set those settings? I may be wrong in what I am saying, but I'm sure someone with an Asus board will respond soon.
My System SpecsSystem Spec

 Locking up computer - CPU Vcore experiencing massive fluctuation(33%)

Thread Tools

Similar help and support threads
Thread Forum
BSOD after starting up computer, first time experiencing
EDIT: Solved for now Hey all, Just booted up, and about 20 seconds after getting into Windows, I got a BSOD. I wasn't looking at the screen when it happened but I briefly saw some type of counter, increasing in number, up to 100, at which point the computer restarted. Any clues? Thanks for...
BSOD Help and Support
Computer Locking Up/Experiencing BSOD While Playing Games and Browsing
Unfortunately, I can't provide a whole lot of information on this problem, as there doesn't seem to be any single, consistent action that causes it. I have now experienced two BSODs, one during Metal Gear Solid 5, the other I believe was merely surfing the internet using Chrome. However, possibly...
BSOD Help and Support
locking your computer
If i leave my computer, for even a short time,when i come to use it i get a message "locking your computer".I have removed the password protection but i want to stop this happening as i am the only user and it's a pain having to wait for my screen to reappear. System is Windows 7 Home Premium 64...
General Discussion
Locking down a base computer
I'm currently trying to lock down my base computer from my friends and was wondering what are the best ways ways on doing it?? When I mean locking it down I mean as far as accessing the data on the computer. I have quite a bit of computer knowledge but I'm like everyone else, I don't know it all....
General Discussion
Computer locking up
So almost eevry time I come back to my computer after a longer period of being away it will completely freeze on me. I have not added any hardware or installed software since this began and have been using this computer for a year and a half. Example would be Im able to use now, and it will run...
BSOD Help and Support

Our Sites

Site Links

About Us

Find Us

Windows 7 Forums is an independent web site and has not been authorized, sponsored, or otherwise approved by Microsoft Corporation. "Windows 7" and related materials are trademarks of Microsoft Corp.

Designer Media Ltd

All times are GMT -5. The time now is 23:30.
Twitter Facebook Google+