Memory compatibility problem?

[veelo2]

I had 2x1GB sticks of RAM. I am trying to add 2X512MB sticks to raise my total to 3GB. For some reason, I can't boot with all four sticks installed together. Each pair works fine seperately, and they look to be the same brand in CPU-Z. I can't figure out how to make them work.

Am I doing something wrong?

 

[honolululu]

Shot in the dark reply bot says, "Try the 1GB sticks in slots 1 and 3 not 2 and 4."

But he rarely gets it right so ymmv.

 

[veelo2]

Thanks for the suggestion, but sadly, shot in the dark reply bot was wrong again. I'm thinking they're not compatible, but I just can't see any reason why that would be the case.

 

[honolululu]

Are you running 1T? What's your mobo? Are you setting the timings manually in BIOS?
Well informed answer bot needs more data.