Frequent ubuntu "freezes" after RAM upgrade

[Odd]

Andrea Fortino wrote:
> Hi,
> I've got a quite old pc with ubuntu 8.04 (32 bit). CPU 2,6GHz, GeForce 
> FX 5200 128MB, motherboard Via P4PB 400 with 3 RAM slots, each one with 
> 512 GB (tot 1,5 GB). Swap partition size is circa 1,5 GB. Checked on 
> internet, max RAM size is 3GB:
> http://www.motherboard.cz/mb/via/p4pb_400.htm
> 
> So I just buyed three RAM blocks (DIMM, each one 1 GB).
> 
> BIOS can read all of 3 GB, but ubuntu often "freezes" after some minutes 
> of work. So I try ubuntu memory test (option from GRUB menu). Test #5 
> ("block move, 64 moves") reports numerous errors. Retried memory test, 
> with only 2 GB (checked every possible combination of 3 blocks): no 
> errors found. So all 3 RAM blocks are ok, I think.
> 
> Then I decide, not so hopefully, to upgrade BIOS:
> http://www.via.com.tw/en/products/mainboards/others/p4pb_400.jsp
> No changes.
> 
> As last attempt, I install 2.6.24-26-server kernel. Again, no changes 
> (ubuntu still freezes after few minutes of uptime)
> 
> What do you think? Any solutions?

Some older motherboards have problems with delivering enough
power to all DIMM slots when they are fully populated. I suggest
you try to increase the voltage in the BIOS, or if there is a jumper
for it on the motherboard, try via that. But don't up the voltage too
much, as it could fry your memory modules. Start  with the default
value and increase it with 0.1 - 0.2 - 0.3. I would be careful trying it
beyond that, but that's up to you.

I did this on a ASUS motherboard with VIA chipset years ago as
it did not deliver enough juice to the memory, and was unstable.
After that it was rock solid.

-- 
Odd