Memoryy question

I had 1gb of memory when i bought my computer, it was 2 sticks of 512mb in two first slots and they are running at 533mhz speed DDR2, now i bought 2 gigs of memory PNY DDR2 667mhz, and I just added it so I have 3 gigs now, well my question is will my computer run faster with only 2 gigs of 667mhz ram than 3 gigs with 533mhz also included, would it be faster if I just took the two sticks 512mb 533mhz out, or its good to have them all together?

The 2 gigs of 667 will be faster overall.

The ram subsystem dictates that any ram regardless of spec is only as fast as the slowest stick of ram. Meaning your 667 is being forced to run at 533.

Taking the other sticks out will get you tighter timings and allow the ram to run at its full intended 667.