Upgrading RAM error

[formula2121]

I currently have 2 PC2100 DDR 256MB 266mhz of RAM and I wanted to upgrade with another 512. So i bought 1 kingston PC3200/PC2700/PC2100 with 512MB DDR and 400mhz.

The problem i am having is that only sometimes when I restart my computer every program that tries to run will crash saying something like system reference error, but if I reboot my system a few times everything seems to work fine.

I think it might be the different bus speeds, but I thought that the 400mhz would clock down automatically. Is there anything I can do to solve this problem? Do you think the computer is having a hard time determining the bus speed of the ram?

Do you think i should go into the BIOS and try to limit the RAM bus to only 266mhz instead of having it on auto.

thanks for the help

 

[RGELLIS]

To be honest, you might as well remove the 256 stick, as the 512 stick at DDR400 will just slow it down, you could get better performance with just the 512 stick at DDR400, as the 256 stick will be so slow, and 256 more isnt going to make the slightest bit of difference anyway!

 

[formula2121]

but i have 2 256 sticks, you think i should take both of them out?

 

[Trotter]

Put the 512 in the first slot.

Your computer will downclock the 400 to the slower speed.

I've got a gig of DDR400 in my old eMachine along side a stick of 256 PC2100. No problems.

 

[formula2121]

I did change the RAM to the first slot a couple of days ago and so far no problem, and you just confirmed that i should do it. So I think the problem is fixed. I thought that no matter how much ram you have it runs as one unit meaning it dosnt write to a specific RAM first, I guess i was wrong.

 

[Trotter]

The rule of thumb is to put the biggest stick in the first slot.