I haven't seen a mobo with slots for both DDR & SD ram.
Do anyone knows such a mobo?
Look here : *eu.shuttle.com/archive/en/mv42n.htm#specificatio
And here : *www.shentech.com/jep4pe4viap41.html
Two of my friends are still using such vintage boards.
remove the SDRAM and install 2x512 MB DDR .. DDR requires that u install the RAM in 2 slots of the bank to run at full speed..
correct me if im wrong
Even in dual channel mode you can't achieve the max speed supported by the ram if the motherboard isn't capable.For eg fitting 2 sticks of ddr400 won't make them run at 400 Mhz if the motherboard supports only 266.Instead they'll run at 266Mhz but you'll see a performance gain in dual ch confguration because now 128 bits of data are transferred at once instead of 64.Hence the transfer rate effectively doubles.
And your motherboard should support dual channel mode in the first place.