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Fabian March 13, 2005 15:27

PC restarts suddenly

Im running CFX 5.7.1 on a Pentium IV 3.2 GHz HT with 1Gb RAM and suddenly my pc restarts by itself during simulation.

Have anyone already experienced this??

Glenn Horrocks March 13, 2005 17:48

Re: PC restarts suddenly

Your PC is sick. Contact support for your PC, or if you feel brave you can have a shot at it yourself. Download the latest drivers for things like graphics cards, hard drives, BIOS etc etc and if you are lucky you will fix it. If you are unlucky you'll stuff your computer up even more.

Glenn Horrocks

Jeff March 13, 2005 18:57

Re: PC restarts suddenly
The solver maxes out the CPU at 100% and can cause heat problems which can either 1) cause the CPU to shut down, or 2) reboot the machine, or 3) on older NT systems give the blue screen of death. I've seen all three of these.

Before getting into detailed re-installs and expensive service calls, make sure the dust is swept out of the machine (especially the CPU fans) and that there is proper venelation to the machine (i.e. it's not sitting up against a wall or a desk that's blocking the vents).


Kiddo March 13, 2005 21:54

Re: PC restarts suddenly
You may use the super pi ( to test your cpu at 100% and see if it will still shutdown. If yes, then you should clean or replace your CPU fan.

Charles March 14, 2005 05:25

Re: PC restarts suddenly
It can be any of a number of things. Heat is certainly a possibility and can give some really weird problems, I've just been through an experience where the machine would reboot itself about 5 minutes after starting to edit one specific Word document, but not others. It had no problem running a CFD simulation at 100% of CPU & memory for an hour .... Wiggling the recently refitted CPU heat sink around a bit cured the problem. I guess there was a hot-spot where the heat sink / thermal grease wasn't seating properly. I've also encountered the reboot problem with poor quality memory, I strongly recommend getting top quality memory modules. It can be time-consuming to trace which memory module is at fault. I've also encountered this problem due to a faulty motherboard, where a dual-CPU board was fine when only one CPU was plugged in, but with a second one it rebooted after a while. Replacing the board was the only option.

There is no simple answer, and your desktop support people are unlikely to have a clue, you will get better help from an overclocker! You need to systematically swap parts in and out untill the problem has been identified. Yes, it is a pain, but in my experience it is just as much part of a CFD engineer's work as understanding fluid dynamics, turbulence models and differencing schemes.

Akin March 15, 2005 08:06

Re: PC restarts suddenly
I have had on of the pc's in my cluster restart itself, the problem seems to be bad memory/heat problem (linux). Another time windows resatarted itself, but I think it was an update issue

Walid March 15, 2005 16:05

Re: PC restarts suddenly
There is a problem in your operating system (OS) obviously which relates to somehow of accumulation of hidden works until you system failure. Try to check that with the Microsoft if you've installed it.

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