Cpu architechture compatibility

I have a Intel® D945GCCR (Coconut Creek) Mobo and I wanted to buy a pentium dual core E5700 processor to replace my pentium dual core E2140 processor.Everything is compatible except for one thing.The architecture is a 45nm vs my current processors 65nm.will this pose a problem?I know my mobo supports core 2 duo but since core 2 has lower overclock potential (dont really care about that since my mobo couldn't overclock it anyway) and higher fsb (which i couldn't make use of since the only ones my mobo is compatible with are 800mhz fsb) an other than that its exactly the same but more expensive,it'd be stupid to buy core 2,+ the ones its compatible with have a max of 2.6 ghz per core vs the one that I found: pentium dual core E5700 with 3.0 ghz per core and its $40 less.so please tell me if e5700 is compatible or not in detail.thanks