Frequent ubuntu "freezes" after RAM upgrade

[jerry]

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?
>
> Thank you in advance! :-)
>
> Ciao,
> Andrea
>
>
>
>   
You did not state the specs of the ram that you were using.

According to the manual for your motherboard on page 2-5 you can use 
either sdr sdram or ddr sdram.
SDR ram uses 3.3 volts and ddr ram uses 2.5 volts. They also differ in 
that sdr ram has 168 pins and ddr ram has 184 pins modules. So you may 
have to adjust the ram voltage according to which type of ram you are 
using.
 
http://www.via.com.tw/download/mainboards/3/4/p4pb%20400_manual_v1.0.pdf

A good source for upgrading ram is to use a site like crucial.com to be 
sure to get the proper ram.

Hope this helps.
jerry