Re: [gentoo-user] Random reboots. Where to start?

[Dale]

Paul Hartman wrote:
> When you say "memtest" what memtest are you using, exactly? The one
> from the kernel?
>
> I prefer memtest86+ as it is updated and has support for the latest
> CPUs and memory configurations. You can install it from portage and
> add an entry to your Grub menu and don't need to mess with bootable CD
> or USB or anything like that.
>
> You can test specific ranges, if you suspect the new RAM is causing
> trouble. Full memory testing of all patterns with 16 gigs of RAM can
> take forever, but in my experience tests 5 and 8 in memtest86+ are
> typically the only tests that actually produce errors on modern
> systems. If you're in a hurry you can just run test 5 and that'll give
> you many more passes in a shorter time. I would at least want to run
> this kind of test for 12 hours with no errors before trusting the
> machine. 24 or 48 hours if you can afford the wait. :)
>
> If it does not always recognize the full 16GB i would suspect you need
> to increase the voltage to your RAM. You may also (or instead) need to
> reduce the memory speed.
>
> On my previous motherboard, an Abit, with Patriot DDR2 RAM, it could
> handle 4GB of RAM (2x2GB) no problems, running at recommended voltage
> and full speed. When I doubled that to 8GB (4x2GB) it crashed often,
> but not constantly. It could not pass an overnight memory test. I
> ultimately had to raise the voltage by 0.3 and reduce the speed from
> 800MHz to 667MHz. I ran memtest86+ for 3 days and it had no errors.
> After that it worked like a champ for 2 years, no problems.
>
> Also, if you're using DDR3 which contains XMP data (timing and voltage
> presets, basically) beware that it can sometimes be wrong. I have used
> 2 different brands of RAM whose XMP data did not match the values
> printed on the packaging. The manufacturers both times suggested I use
> what's printed on the packaging and ignore what the chip itself tells
> me.
>
> And of course on my recent Core i7 920 build, I spent a month trying
> to get OCZ Gold RAM to work properly with my Gigabyte motherboard.
> After 2 DOA sticks exchanged and a month of trying everything I could
> possibly think of it still failed memory tests (sometimes it would
> only fail after 5 or 6 hours of testing) and I gave up and returned it
> to the store for a refund. I ordered some Corsair XMS3 RAM online
> instead, it worked right away with the recommended settings, no
> messing around, and I've been running happily ever after. :)
>

I figured out why it appeared not to be testing it all.  I was just 
checking it as I walked by and such and I guess it just happened to be 
testing the first 2Gbs or so each time I walked by.  I did another test 
and just sat and watched a lot of it.  It appears to be testing in 2Gb 
chunks or something.  It would test something to 2Gbs, then test 2Gbs to 
4Gbs and so on.  So, it was testing it all, I was just not there to see 
it do it.  The something in the first 2Gbs is what it needs to load the 
test I guess.  It was just a small amount tho.

Mine is G Skill ram.  It calls for at least 1333 but I got 1600.  I 
usually get a little faster, in case I want to overclock a little but it 
also allows for a ram that may not be quite up to speed.  Plus, it was 
on sale and was actually cheaper than 1333.  lol  That made the sale.  
;-)  It is DDR3 tho.  It is also in ganged mode too.  It is faster that 
way.

I hope I don't have to swap my ram.  I bought it at newegg and the 
shipping would be fun I'm sure.  At least I got plenty to run off of 
while swapping tho.

Thanks.

Dale

:-)  :-)