Is it possible to put ddr2 533 mhz ram in a ddr2 800 mhz slot along with other ddr2 800mhz dimms? If this does work, will all the ram slow down to 533 mhz, or will they run at their own speed?
Provided the RAM is compatible with the motherboard it should work.
It means that the higher speed ram will be clocked down to 533MHz.
However, it's possible that the mixing of RAM may cause some stability issues. I've put mixed RAM speeds in a server before and it ran fine however even though the IBM management stuff switched on a light saying there was a problem.
I'm not guaranteeing it'll work perfectly but I have seen mixed RAM speeds work.