Yes. They are backwards compatible. Even with the installed 800MHz ram It will still only run at 667MHz speeds.
Yes. But it might only run as fast as pc2 5300 sdram. The number indicates the guaranteed speed of the RAM stick:
see: http://www.valuemedia.co.uk/ddr.htm
No, you cannot. PC2 is ddr2 type of memory when PC is ddr. Those types are not compatible.
DDR2. Theres several diffent speed DDR modules, exactly what you will need depends on what CPU you are using, but the slowest DDR2 you can use in this motherbaord is 533, and the fastest DDR2 800. 800 is probably the best to use.
Yes
Although it would probably be possible, depending on the chipset used, it would offer poorer performance.
DDR2 PC2-4200,DDR2 PC2-5300,DDR2 PC2-6400 with a maximum of 1GB per slot (equals 4GB max total system memory)
The ASRock G31M-S uses DDR2-667 or DDR2-800 modules. it supports up to 8 GB of RAM using two 4 GB modules.
Unfortunately you can not. DDR and DDR2 have a different pin arrangement and they will never work in each others slots.
Unfortunately not. DDR has a different amount of pins compared to a stick of DDR II. Also the slot position is slightly different. Hope this helps Be Safe Cadishead Computers
No DDR and DDR2 Slots are differant on Motherboard so cant replace each another
No, you can't use same DIMM slots for DDR2 and DDR3 due to different position of the key and interface incapability.
The type of RAM you use is dependant on what your motherboard and CPU can handle. You want to change from DDR to DDR2? Id' recommend getting a new computer.
Yes, it is backward compatible