Re: [PLUG] How To Diagnose System Instability?

[Eric <eric@lucii.org>]

Casey Bralla wrote:
> Lately my computer has started showing signs of instability.   I get rather 
> frequent SegFaults which pop up windows in KDE and (usually) allow me to 
> restart applications.  The computer is about 8 months old, and had been 
> completely fine up until about a month ago.
>
> At first I thought this was just goofiness with the latest version of KDE, but 
> after I removed half my RAM, the stability improved tremendously.   Also, my 
> BIOS includes the memtest86+ program and it shows errors (sometimes).
>
> I use Gentoo, so am compiling a lot of software.  I've read that recompiling 
> the kernel is a great way to identify hardware problems since it exercises the 
> whole system so thoroughly. <sigh>
>
> So I'm struggling to identify which component(s) of my system are causing the 
> instability.   Here are the things I've tried, with very limited success:
>
>  - run memtest86+.  (Sometimes shows errors, but sometimes can run overnight 
> without any problems)
>  - Removed half the 4 memory chips. [I had 8 GBytes, so could spare the RAM] 
> (This helped, but not 100%)
>  - Used to BIOS to restrict my 4-core AMD Phenom to a single core (no 
> improvement)
>  - Used the BIOS to raise the RAM voltage slightly (no apparent effect)
>  - Used the BIOS to slow the DDR-800 chips to DDR-400 speeds (no apparent 
> effect)
>
>
> Here are the things I still want to try:
>
>  - Swap the remaining RAM chips into the other sockets
>  - Swap out the power supply
>
>
> Beyond these tasks, does anybody have any suggestions to help identify the 
> cause of the instability?   I would hate to have to replace the motherboard.  
> And how would I "prove" that the motherboard is the problem? 
>
>
>
> BTW, here are the specs:
>
> Motherboard: BIOStar TA790GX
> CPU: AMD Phenom II X4 940
> RAM: Crucial "Ballistix Tracer" 2 sets of 2@2 GBytes each
> Disk: Western Digital SATA
> Video: Sparkle GForce 7600 PCI Express
> Power Supply: Raidmax 730 Watt
>   
I agree with both of your proposed tasks... that is what I'd do.

When I had some odd freezing and/or crashing behavior from my old Athlon
800 workstation I ended up replacing the power supply and that fixed the
problem.  It's hard to diagnose a power supply that does not fail
outright.  Perhaps they just get "noisy" or "weak"?
Having said that, my initial power supply was a 350 Watt generic type -
although it was rated for use with the Athlon processor - and my memory
tests never failed. 

When memtest shows the memory as bad does the error occur in the same
place in memory each time?  If the memory errors "move" then that might
indicate that the problem is elsewhere. 

Maybe all the compiling with Gentoo wore out the system early?  :-)  <ducks>

Hope that is of some help.  Good luck.

Eric

-- 
#  Eric Lucas
#
#                "Oh, I have slipped the surly bond of earth
#                 And danced the skies on laughter-silvered wings...
#                                        -- John Gillespie Magee Jr

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