I've got an old HP business tower that only officially supports 4GB of DDR2 and has 4 slots. Works just fine on 800MHz using 4GB total. Needed to use 667MHz D

I've got an old HP business tower that only officially supports 4GB of DDR2 and has 4 slots. Works just fine on 800MHz using 4GB total. Needed to use 667MHz DIMMS so it would handle 8GB. Almost worked with 800 but was unstable.