That doesn't surprise me as about the only nVidia based Intel chipset that overclocked Quads reasonably well were the DDR3 790i's. They're not cheap either and honestly if overclocking was part of the plan, you're probably better off selling your DDR2, 780i and Q9550 to then go Core i7. You should get pretty close to retail value of the Q9550 as they're in demand, the 780i should go for £80-100inc and whatever RAM you have shouldn't have trouble shifting either. Good X58 boards like the EX58 UD3R start from £155, you can find the i7 920 for just over £200 I believe and Tri Channel DDR3 kits have dropped in price quite nicely