freeze interview questions
Top freeze frequently asked interview questions
My computer started to freeze at irregular times for 3 weeks now.
Please note that this question change with each things that i try. (For additional details)
- My computer freezes, the video stops. (No graphic glitches, it just stops)
- Sounds stops too.
- Sometimes, randomly, the screen on my G-15 keyboard flickers and I see characters not at the right places. Usually happens for about 1-2 seconds and a bit before my computer freezes.
- I have to keep the power button pressed for 4 seconds to shut my computer down.
- I still hear my hard drives and fans working.
- Sometimes it works with no problems for a full day, some other times it just keeps freezing each time I restart my computer and I have to leave it for the rest of the day.
- Sometimes my mouse freezes for a fraction of a second (Like 0.01 to 0.2 seconds) quite randomly, usually before it freezes.
- No errors spotted by the "Action center" unlike when I had problems with my last video card on this system (Driver errors).
- My G-15 LCD screen also freezes.
- Sometimes my G-15 LCD screen flickers and characters gets carried around temporary under heavy load.
- Now, most of the times, the BIOS hard disks boot order gets reversed for some reason and I have to put it to the right one and save each times I boot. (Might be unrelated, not sure, but it first started yesterday)
What I did so far
- I have had similar problems in the past and I had changed my hard drive (It was faulty), so I tested my software RAID-0 array and it was faulty so I changed it. (I reinstalled Windows 7 with this part). I also tested with unplugging my secondary hard drive.
- My CPU was running at about 100 degree Celsius, I removed the dust between the fans and the heat sink and it's now between 45-55.
- I ran a CPU stress-test and it didn't froze during the tests (using
Prime95 on all cores)
- Ran a memory test (using
memtest86+) for a single pass and there were no errors.
- Ran a GPU stress test with
furmark and it didn't froze during the tests. (No artefacts either)
- I had troubles with my graphic card when I got it, but I think that it got fixed with a driver update.
- I checked the voltages in my BIOS setup and they all seemed ok (±0.2 I think).
- I have run on the computer without problems with Fedora 15 on an external hard drive (apart that it couldn't load Gnome 3 and was reverting to Gnome 2, didn't want to install drivers since I use it on multiple computers) I used it to back up my files from the raid array to my 1TB hard drive for the reinstallation of Windows. (So the crashes only happened on Windows) [The external hard drive is plugged directly on a SATA port]
- I contacted EVGA (My graphic card vendor) and pointed them on this question, I'm looking for an answer.
sensors on Fedora 15 and got this output: http://pastebin.com/0BHJnAvu
- Ran 6 short different CPU stress test on Fedora 15 (Haven't found any complete stress testers for Linux) and it didn't crash.
- Changed the thermal paste to some Artic Silver 5 for my CPU and stress tested the CPU, temperature was at 50 idle, then 64 highest and slowly went down to 62 during the test.
- Ran some stress testing with a temporary graphic card and it went ok.
- Ran furmark stress test with my original graphic card and it froze again. GPU had a temp of 74C, a CPU temp of 58C and a mobo temp of 40C or 45C (Dunno which one it is from SpeedFan).
- Ran a furmark stress test and a CPU stress test at the same time, results: http://pastebin.com/2t6PLpdJ
- I have been using my computer without stressing it for about 2 hours now and no crashes yet. I also have disabled the
AMD Cool'n'quiet function on the BIOS for a more regular power to the CPU. When I ran
Furmark without C'n'q my computer didn't freeze but I had a "Driver Kernel Error" that have recovered (And
Furmark crashed) all that while running a CPU stress test. The computer eventually froze without me being at it, but this time my screen just went on sleep and I couldn't wake it.
- Using the stability tester in nTune my computer froze again (In the same manner as before). I noticed that Speedfan gives me a -12V of -16.97V and a -5V of -8.78V.
I have swapped my G-15 with another basic USB keyboard (HP) and I have run
furmark for about 10 minutes with a CPU stability test running each 60 seconds for 30 seconds and my computer haven't crashed yet.
- Ran some more extended tests without my G-15 and it freeze like it usually do.
- Removed the nForce Hard disk controller.
- Disabled command queuing in the NVIDIA nForce SATA Controller for both port 0 and port 1 (Errors from the logs)
- Used CPUID HwMonitor, here are the voltages: http://pastebin.com/dfM7p4jV
- Changed some configurations in the motherboard BIOS: Disabled
PEG Link Mode, Changed
AI Tuning to
Standard, Disabled the
1394 Controller, Disabled
HD Audio, Disabled
JMicron RAID controller and Disabled
- "A little hope", my computer frozen while watching a youtube video, but not from GPU and CPU 10 hours straight test.
- I have put my BIOS back to defaults and: Disabled
PEG Link Mode, Disabled
HD Audio, Disabled
JMicron RAID Controler, Disabled
Serial Port Address, Disabled
Parallel Port Address and Disabled
Onboard 1394 Controller.
- I changed the SATA cable for the 750GB hard drive and I also changed the slots at which they were plugged (1->2, 2->3, 3->4).
- Changed the power saving feature of my graphic card from "Adaptive" to "Maximum performance".
- Ran ECGA OC Scanner and got no freeze and no artifacts
- I installed the Logitech drivers for my G-15 keyboard and my G-500 mouse and it restarted to freeze.
- I removed the Logitech drivers for my G-15 keyboard and my G-500 mouse and it still freeze.
- After changing everything except the hard drives, graphic card and power supply my computer is running very fine and I haven't run into any problems (This is with the exact same install of Windows that I had problems with my old motherboard). After removing my motherboard I have found some cambered capacitors (2) which might be the source of the problems. Since it almost clearly was a motherboard problem caused by these capacitors I am going to accept the answer that is the most related to this solution.
When it happens
- When I play video games (Mostly)
- When I play flash games (Second most)
- When I'm looking at my desktop background (It rarely happens when I have a window open, but it does, sometimes)
- When my Graphic card and my CPU are stressed.
- Sometimes when my Graphic card is stressed.
- Sometimes when my CPU is stressed.
- Windows Seven x64 Home Premium
- Motherboard: M2N-SLI Deluxe
- Graphic card: EVGA GTX 570 (The non-oc one) [nVidia driver version 275.33 from EVGA's website]
- CPU: AMD Phenom 9950 x2 @ 2.6GHz
- Memory: Kingston 4x2GB Dual Channel (Pretty basic memory sticks)
- Hard drives: Was 2x250GB (Western digital caviar) in raid-0 + 1TB (WD caviar black), I replaced the raid array with a 750GB (WD caviar black) [Yes I removed the array from the raid configurations]
- 750W Power supply
- No overclocking. Ever.
- There have been some power-downs like 4-5 weeks ago, but the problem didn't start immediately after. (I wasn't home, so my computer got shut-down)
- Event logs (Warnings, errors and critical errors) for the last 24 hours: http://pastebin.com/Bvvk31T7
I would like to thank everyone who have been participating, it's really nice to see that much people ready to help others. There was many great answers that might help other people with similar problems in the future (at least I hope so).
In this situation, how can I successfully pin-point the current hardware problem? (If it's a hardware problem)
As a lot of us encounter freezes or crashes, I am wondering how do I manually initiate a computer to freeze in order to create a memory dump to view and diagnose any issues that may be involved with the crash?
I am looking on how to force the computer to crash instead of waiting for the computer to do it itself.
I was wondering if there is a way to freeze any process for a certain amount of time?
What I mean is that: is it possible for one application (probably running as root) to pause the execution of another already running process (any process, both GUI and command line) and then resume it later? In other words I don't want certain processes to be scheduled by the linux scheduler for a certain amount of time.
I'm running Gnome with compiz in Ubuntu 10.04. Sometimes the gui will freeze. I can move the mouse, but I can't interact with programs. The only thing I can do is go to a terminal window with Alt+Ctrl+F(n). From there I login and do a sudo reboot. What else can I do at the terminal instead of rebooting to deal with this problem when it comes up?
What are some common guidelines and issues related to hardware being the issue of a computer crash?
What should I look for and how do I troubleshoot these problems?
What are some tools that are useful in diagnosing these hardware related crashes?
I am looking to be able to isolate the problematic device with specific tools and guidelines. For example if device X is causing system failure how do I go about diagnosing it?
Basically, whenever I turn on my computer, it gets to the
Starting Windows phase and just stays there. The startup animation still plays, yet it gets nowhere.
I have tried booting into safe mode, however it gets stuck at loading
CLASSPNP.SYS. It then freezes there and doesn't continue booting.
I have tried booting into recovery mode from the hard drive, and it freezes after displaying the background image. I have tried booting from a recovery CD, which works, and I was able to use system restore. However, using system restore did not fix it, and it still is stuck at the
Starting Windows screen.
I have tried booting a Windows CD (Windows 8 Retail Installer) to see if I could upgrade it to fix this issue, however that froze at a blank screen after it got past the boot logo.
I have tried changing around the BIOS settings (including resetting), to no avail.
I have tried re-plugging the internal PSU cables (this is a custom-built desktop), yet this has changed nothing.
I can boot into a loopback Ubuntu install on the same drive, which works fine, other than the fact that it has issues with some of the USB ports and the network card.
This system has worked fine for the past few months, completely stable, and nothing in the configuration has changed before this error started happening.
Startup Repair on the Windows recovery CD doesn't find any issues.
Unplugging my secondary hard drive or swapping around memory doesn't change anything.
The hard drive itself is fine, it hasn't shown any signs of failure and once again, boots my other OS fine.
If anyone could help with this, that would be great. I can't seem to find any possible solution to this.
If it makes any difference, my system specs are as follows:
4GB of DDR3
Radeon HD 6870
I'd like to not have to reinstall Windows, for I have more than a terabyte of data that I would have to back up if that becomes the only option.
EDIT: I have since tried the following:
Tried the solution involving restoring files from
RegBackup, which changed nothing.
Tried testing everything with Hiren's boot CD, everything comes back as fine.
Tried disabling everything unnecessary in the BIOS and unplugging everything unneeded, it still hangs.
Tried swapping out every possible combination of RAM, it still has the same result. The RAM is not at fault it seems
Tried every GPU I own (which is many!) and it still hangs at the exact same place.
Tried minimizing the power consumption as much as possible, even using an old PCI graphics card. It still hangs at the same place in the same way, signifying that it's not the PSU at fault.
Tried resetting the BIOS again, still nothing.
Tried every possible combination of BIOS options, even downclocking everything, it still hangs in the same spot.
Tried upgrading the BIOS from version
FD, which changed nothing.
Based on this, I would conclude the motherboard to be at fault. Are there any other possibilities? I don't want to spend $150 for a new motherboard.
EDIT 2: This is what it gets stuck at when I try to boot into safe mode:
Note the slight graphical corruption at the top of the screen. No matter how I set up the system, this seems to be there. In addition, either it has stopped booting into safe mode now, or it takes upwards of 2+ hours, and I haven't left it running for that long.
I built a desktop computer a couple years back with the following specs:
- CPU: Intel Core 2 Quad Q9300 Yorkfield 2.5GHz 6 MB L2 Cache LGA 775 95W Quad-Core Processor BX80580Q9300
- Motherboard: EVGA 122-CK-NF68-T1 LGA 775 NVIDIA nForce 680i SLI ATX Intel Motherboard
- Video Card: Two EVGA 256-P2-N758-TR GeForce 8600GT SCC 256 MB 128-bit GDDR3 PCI Express x16 SLI Supported Video Card
- PSU: SeaSonic S12 Energy Plus SS-550HT 550W ATX12V V2.3 / EPS12V V2.91 SLI Certified CrossFire Ready 80 PLUS Certified Active PFC Power Supply
- Memory: Two G.SKILL 4 GB (2 x 2 GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model F2-6400CL5D-4GBPQ
Since its inception, the machine has periodically locked up, the regularity having varied over the years from once a day to once a month. Typically, lockups happen once every few days.
By "lockup" I mean my computer just freezes. The screen locks up, I can't move the mouse. Hitting keys on my keyboard that normally turn LEDs on or off on the keyboard (such as Caps Lock) no longer turn the LEDs on or off. If there was music playing at the time of the lockup, noise keeps coming out of the speakers, but it's just the current frequency/note that plays indefinitely. There is no BSOD.
When such a lockup occurs I have to do a hard reboot by either turning off the computer or hitting the reset button.
I have the most recent version of the NVIDIA hardware drivers, and update them semi-regularly, but that hasn't seemed to help. I am currently using Windows 7 x64, but was previously using Windows Server 2003 x64 and having the same lockup issues.
My guess is that it's somehow video driver or motherboard related, but I don't know how to go about diagnosing this problem to narrow down which of the two is the culprit.
Additional information re: cooling
Regarding cooling... I've not installed any after-market cooling systems aside from two regular fans I scavenged from an older computer. The fan atop the CPU is the one that shipped with it. One of the two scavenged fans I added it located at the bottom tower of the corner, in an attempt to create some airflow from front to back. The second fan is pointed directly at the two video cards.
SpeedFan installation and readings
Per studiohack's suggestion, I installed SpeedFan, which provided the following temperature readings:
- GPU: 63C
- GPU: 65C
- System: 76C
- CPU: 64C
- AUX: 36C
- Core 0: 78C
- Core 1: 76C
- Core 2: 79C
- Core 3: 79C
Update #3: Another Lockup :-(
Well, I had another lockup last night. :-( SpeedFan reported the CPU temp at 38 C when it happened, and there was no spike in temperature leading up to the freeze.
One thing I notice is that the freeze seems more likely to happen if I am watching a video. In fact, of the last 5 freezes over the past month, 4 of them have been while watching a video on Flickr. Not necessarily the same video, but a video nevertheless. I don't know if this is just coincidence or if it means anything. (As an aside, each night before bedtime my 2 year old daughter sits on my lap and watches some home videos on Flickr and, in the last month, has learned the phrase, "Uh oh, computer broke.")
Update #4: MemTest86 and 3DMark06 Test Results:
Per suggestions in the comments, I ran the MemTest86 overnight and it cycled through the 8 GB of memory 5 times without error. I also ran the 3DMark06 test without a problem (see my scores at http://3dmark.com/3dm06/15163549).
So... what now? :-)
Any further suggestions on what to check? Is there some way to get a stack trace or something when the computer locks like that?
I have never did figure out the particular problems, but based on the suggestions here and elsewhere, I'm presuming it was a motherboard issue. In any event, I recently upgraded my system, buying a new motherbeard, PSU, CPU, and RAM, and that new rig has been working splendidly the past several weeks. I am using the same graphic cards as in the old setup, so I think it's safe to reason that they weren't the cause of the problem.
All GNU/Linux distributions I tested so far have the problem that whenever the ram gets filled and the system begins swapping, the whole desktop and graphical user interface becomes unresponsive as hell to an extent that sometimes I have to wait about 5-10 seconds after having moved the physical mouse until the mouse pointer is actually moving.
This is kind of an annoying behaviour, especially on systems with low ram.
Is there any way to give some applications/jobs, like the desktop environment etc., a higher priority to stay in ram than other applications, so that the application actually hogging all the memory gets swapped before the desktop environment etc.?
I'm talking of the case when the entire RAM is used so it will always start swapping if it isn't disabled (I don't want processes to be killed randomly). I had this problem not only in low ram environments, but as well with 8GiB of ram on my desktop machine, partly due to many VMs partly because of memory leakage. ZRAM isn't a solution either as it's only delaying the problem. The only solution I can think of for this problem is some userspace utility or kernel API that allows to prevent certain jobs to be swapped at all or at least make it very unlikely. Does anybody know another solution or knows anything about such a tool or API in existence or being planned?
2nd EDIT: ulatencyd doesn't seem to work with newer versions of systemd, according to https://aur.archlinux.org/packages/ulatencyd-git/ and https://wiki.archlinux.org/index.php/Ulatencyd . This may be because systemd took over full control of cgroups from a userspace perspective if I understand it correctly.
I have a relatively new (under 2 yrs old) Windows 7 machine. It has 9GB of RAM, and an i7 core CPU (930 @ 2.8GHz w/ 8 CPUs). After about 8 months since a clean install, I noticed my computer was running slowly. I figure it was fragmentation etc, and I did a complete wipe & clean reinstall.
However, my problems are somehow persisting. The computer is running painfully slowly (but in leaps and bounds - sometimes it will work fine for 3 hrs, then suddenly freeze up just from clicking the start button). The 'freezes' happen randomly - not during any especially intensive computing. I initially thought something might be eating through my CPU and/or Memory, but Task Manager indicates that neither the CPU or Memory spike. In fact, even during serious lag, CPU usage remains at less than 5% and Memory at ~ 1.5GB.
It's beyond me why a fresh install on a powerful machine is performing so poorly. And it certainly is frustrating! What could be causing the poor performance, and what can I do to fix it?
I am running Snow Leopard. It is up to date. Every few days, I get the "Spinning Wheel of Death."
- I can't do anything except hold down the power button to shut off my MacBook Pro.
- I've even tried a
kill -9 -1 from a root shell that was already opened. It just hangs.
- The Spin Control app just says "Sampling" on a few of the apps but is unresponsive.
Do I have any other options to shut down my laptop? I don't like to just power it off.
Update: I have no idea which app is doing this. At the moment it appears random. My fan does not spin up. Maybe it's a networking thing?
Update: Dead again. This time I had X11 running and no matter what app I switched to, I got that app's menu bar and the X11 screen. I ping and the Internet doesn't respond. My Apple router is working because I'm streaming Pandora over WiFi. I turn off the wifi and I'm still screwed. I try to power off and it won't shutdowm because X11 is running. If course, I can't kill it. Press and hold... boom. This is not how an OS is supposed to work!
We've all experienced it--some program is asked to do something that requires a huge amount of memory. It dutifully tries to allocate all this memory, and the system immediately begins thrashing, swapping endlessly and becoming sluggish or non-responsive.
I most recently experienced this on my Ubuntu laptop due to a Matlab script trying to allocate a ridiculously huge matrix. After ~5+ minutes of thrashing, I was able to Ctrl-F1 to a console and kill Matlab. I would much rather have some hot-key that would have given me control of the system immediately and allowed me to kill the offending process; or, perhaps, simply silently refuse to allocate such a large buffer.
What is the quickest way to regain control of a Linux system that has become nonresponsive or extremely sluggish due to excessive swapping?
Is there an effective way to prevent such swapping from occurring in the first place, for instance by limiting the amount of memory a process is allowed to try to allocate?
Occasionally one of my computers will get so bogged down that everything locks up, Ctrl+Alt+Del doesn't work, Task Manager won't open, or they work, but are opening so slowly that it will take hours or days to shut down other processes and regain control of the computer, etc.
Is there a way to, for instance, force Task Manager to be highest priority so it always opens immediately with Ctrl+Shift+Esc even when some other process/driver is hogging the CPU? Is there some other program that can run in the background and open immediately like this?
This question isn't about fixing "underlying problems". No matter how much memory you have, it's still possible for a rogue process to eat it all up and lock up the computer in page fault thrashing, hog the CPU, etc. This question is about how to take back control of the computer when that happens.
Basically when these kind of lock-ups happen, I want to open some kind of task manager that pauses every other process and allows me to kill one of them, and then let everything resume so I can save my work, etc. Otherwise my only option is to hold down the power button.
Antifreeze is supposed to do exactly what i want, pausing all other applications and starting a task manager to kill the offender, but in my testing, it actually does neither.
I am an early adopter of Windows 10, and I am a .NET / Web developer so I like to push the bounds a bit when testing out a new OS. I also try to work against the latest / freshest builds available.
With prior releases of windows, when the Windows button and taskbar became unresponsive you could kill the
explorer.exe process in Task Manager.
With Windows 10 (RC), the game has changed a bit. Anyone know how to reset the
How can I recover when the OS is hung up and the start button is unresponsive.
I'd prefer not to (a) log out or (b) restart.
This is more of a curiosity than a REAL problem, but thanks in advance!
UPDATE / CLARIFICATION
The new task manager doesn't show process names, and there is an application called "Windows Explorer" but I think its limited to the actual file browser (Explorer) and restarting it has no effect on the start menu.
I started an installation of the Xcode 4 developer's preview last night before going to bed. When I woke up, the installation had popped up a message saying to close Xcode first (doh!). I did so, but whatever script had displayed the message seemed to have hung because the (uncancellable) message wouldn't disappear, and the installer wouldn't progress.
After force quitting the Installer app, the message above was still showing, so I restarted my MacBook Pro and then tried the installation again. This time it wouldn't even start, instead showing one of those candy-stripe activity bars and the message:
Waiting for other installations to finish
At this point, I'm stumped. There are no other installations in progress, so there must be some artifact left over from the interrupted install that's gumming up the works. But what?
I tried to print a doc in word, and word froze. Is there any way for me to see what resource it's waiting for?
I'm using windows XP and word 2007 (though I imagine the answer doesn't depend on the process that froze)