Re: [gentoo-user] Ramifications of memtest86

[Dale]

chrome://messenger/locale/messengercompose/composeMsgs.properties:
> Hi, Dale,
>
> On Fri, Feb 12, 2010 at 06:43:46AM -0600, Dale wrote:
>
>> chrome://messenger/locale/messengercompose/composeMsgs.properties:
>>
>>> On Fri, Feb 12, 2010 at 11:22:21AM +0000, Alan Mackenzie wrote:
>>>
>
>
>>>> When I run memtest86 from the gentoo boot disk, it signals millions
>>>> of failures in b11 of 32 bit words.
>>>>
>
>
>>>> I'll try unplugging and replugging these.
>>>>
>
>>> No help.  :-(
>>>
>
>>> No matter how I plug in the RAM (4 combinations of 2 sticks into 2
>>> pairs of slots) it is always b11 which fails and always at an address
>>> ending in (hex) 0 or 8.
>>>
>
>>> How is this DDR3 Ram organised?  Is each stick 64 bits wide, or are
>>> they 32 bits wide, being accessed by the motherboard pairwisely?  If
>>> the latter, I would have exected the failure to move to address ....4
>>> and ....C when I swap the two sticks.  Am I being prematurely
>>> pessimistic in thinking the motherboard might be the fault?
>>>
>
>
>> Sounds to me like the mobo may have issues.  If swapping the ram around
>> doesn't move the error, then the chips on the mobo that connect to the
>> ram may be bad.
>>
> So the RAM sticks are each 32 bits wide, then?
>

I run 32 bit here.  Mine doesn't care where they are but yours may be 
different.

>
>> I would still rule out power issues if you can.  A bad power supply, or
>> a weak one, can cause some pretty weird problems.
>>
> The power supply is brand new, from a reputable manufacturer.  Surely if
> the power supply were dicky, I'd get RAM errors in some other bit
> position inside a 32-bit word.  Or maybe the RAM into which memtest86 is
> loaded is also faulty.  ;-(
>
>
>> Dale
>>
>

Where the error is could depend on a single transistor that is maybe not 
as sensitive as the others.  It's sort of like a chain.  It's only as 
strong as its weakest link.  It could be that whatever is going wrong 
could be right on the edge of others not working either.  The one that 
is failing is just the first if it is a power problem.  That's where the 
power problem thought comes from.  Have you had a look here for well 
tested power supplies?

http://www.overclockers.com/forums/showthread.php?t=458204

That said, it could be a lot of things.  It could be a bad chip on the 
mobo, a piece of dust in the wrong place or any number of other things.  
It's finding it that is so much fun.

I would also check to see if it is a heat related issue.  If it runs 
fine cold, that could point to the "dust" theory since it is 
consistently broke.  If it only does it when hot, then that could be a 
chip problem.

Again, lots of things it could be.  So far, everybody has replied with 
good ideas to check.  There are lots of them.

Dale

:-)  :-)