> Memory: 2047M 2126 MB/s > [dual-channel] > > Memory: 2559M 1103 MB/s > [single-channel] That is a large difference, but it may be more due to mixing different sized (and unmatched) dimms more than dual vs single channel. Go with that dual-channel config. > RAM: 159 MHz (DDR319) That's some old stuff you have there...