I'm still sitting a on holiday cash windfall and I'm aching to get a gtx 570. The gtx 275 in my computer now (see below) was a 'stop gap' measure for my (what was once new) rig, purchased for a bargan price while waiting for DX11 cards to arrive on the scene (my ol' 8800gts 512 wasn't worthy IMO) so I'm not that attached to it. After reading though all of SpiritFly's benches (hats off to these excellent efforts) I'm really stoked at the potential benefits of the upgrade, yet my rig's stable OC tops out at 4Ghz (if I really want to push it w/no HT). So I wonder: since my i7 is not even close to 4.4Ghz, is getting a gtx 570 really going to matter much , performance wise, over my gtx 275 for FSX?Currently I like to use a 3.8Ghz OC with FSX since it requires a lot less voltage than 4.0 and I can keep HT enabled while seeing very little performance difference. I'm experimentally using an AffinityMask of 244 which allows four texture/terrain threads to run HT, i.e. 4 threads share 2 cores, since this seems to provide smoother performance than no AM, AM=84 (HT) or 14 (non-HT). And BTW, a gtx 580 is well beyond my budget. Thanks for reading.

Deleted. I was talking nonsense.

After seeing all the enthuastic replies , I've decide get a gtx 560 ti since it more closely matches the oomph of my computer/monitor/wallet. I'll run a few informal before/after FSX tests on the system and post the results if anyone wants it, otherwise I won't bother. BTW, I did own a gf4200 ti way back in '02.

I'm really interested in your findings about the 560. I'm still in doubts between getting a 560 or 570.