Pc won`t` upgrade

[Jk40]

Hi
This is my first post, I am having trouble with my pc memory.
I have 1Gig (DDR2 pc4300)of memory and thought i will upgrade to 2Gb so i purchased 2x512 mb(DDR2 pc4200) of ram and now have 2048 mb configured 4x512mb all are CL4

I can not get all 4 to work together on dual channel,the pc freezes/colour distorts and i have to restart,i notice that the Cpu goes up and down up to 100% usage when i open programmes and sometimes just loading the desktop.This happens 8 times out of 10 but will always happen within 10 miniute or so.

If i run three modules 3x512mb it will run better but it will crash after say 40 min if i open 2 or 3 programes.I have run memtet 86+ over 5 passes but it detects no errors and also takes ages lol.
I am thinking it could be a problem with the cpu but it runs ok with 2x512mb apart from the odd freeze about once a day.
Memory shows on system and i dont think it is bad.
I have the page file set @1578mb which is system managed,whether that makes any difference.

Any ideas why it will run 2x512mb ok but not 4x512mb or sometmes 3x512mb.

John K.

Acer T180
Amd 64x2 4200
Installed memory 2x512mb (works ok)
nvidia 6100 n405
160gig Hd
vista premium.

 

[PC eye]

You may want a Welcome to the Computer Forum! first http://www.computerforum.com/70672-official-welcome-thread.html and the reminder to new members to review the http://www.computerforum.com/52038-forum-rules.html to get you started off.

Can I assume the PC4200-PC4300 is a typo there? If not you probably mixed one type of memory with another or received faulty dimms. If the first pair of 512s are value ram and were mixed with performance memory the obvious problem would be seen with the timings. The clash betweein two different types would be the most likely answer.

Have you tried the new pair by themselves to see how those run on their own? Sometimes the brand of memory isn't suitable for the make and model board. These are a few things to look at there.

One other thing to add to the list is different voltages between the two pairs. If one is 1.8v while the other is 2v that will spell trouble too.