Your MB has the P35 chipset with pcie1.1X16, usually the newer GPU will be backward compatible to the old version pcie, if it does not, then you have to update the BIOS. And you can use the new GPU in the new PC if you want to upgrade your PC later. Also make sure you have a good PSU for the gtx970, because the gtx970 requires at least 500-550W with 28A on the +12V rail, and 2x 6pin pcie power connectors two.