Two weeks ago I was able to try a GTX295 1.8Gb with FSX.Compared to my GTX260 896Mb OC I got around 25% more framerates and FSX was completely smooth.Last week I tried a GTX275 with 2Gb : framerates a bit better than the GTX295 , but completely smooth with all settings to max.Over the last 3 days I tried an EVGA GTX285 FTW ( fastest GTX285 card ) 1Gb.Framerates were less than with the GTX295 and GTX275 and it had those irritating micro stutters at the far outsides.Using 2 monitors with my "old" DH2Go the performance differences are much smaller. Because nowadays I use 3 26" monitors connected to a TH2Go it is very hard on the system.FSX does not use SLI, but I was wondering if the second memory pack is being used, so a total of 1.8 Gb.That would explain the better and smoother performance of the GTX295 1.8Gb over the GTX285 1Gb and the almost same perfomance as the GTX275 2Gb....

Two weeks ago I was able to try a GTX295 1.8Gb with FSX.Compared to my GTX260 896Mb OC I got around 25% more framerates and FSX was completely smooth.Last week I tried a GTX275 with 2Gb : framerates a bit better than the GTX295 , but completely smooth with all settings to max.Over the last 3 days I tried an EVGA GTX285 FTW ( fastest GTX285 card ) 1Gb.Framerates were less than with the GTX295 and GTX275 and it had those irritating micro stutters at the far outsides.Using 2 monitors with my "old" DH2Go the performance differences are much smaller. Because nowadays I use 3 26" monitors connected to a TH2Go it is very hard on the system.FSX does not use SLI, but I was wondering if the second memory pack is being used, so a total of 1.8 Gb.That would explain the better and smoother performance of the GTX295 1.8Gb over the GTX285 1Gb and the almost same perfomance as the GTX275 2Gb....

as far as I am aware - as you rightly say FSX does not support SLIthe memory "banks" are not shared memory, each GPU (as far as I think) can only access each memory pool- they are dedicated to eacheach GPU is equivalent to somewhere between a GTX260 and GTX280 - I think RAM performance and core speed are that per GTX260, but has same number of stream processors as a GTX280 (not sure if FSX uses the stream processors ?)therefore a GTX295 should be equivalent to somwhere between GTX260 and GTX280 in performance - leaning more towards the GTX260 as RAM bandwidth and speed is important to FSX, but certainly less performance than a GTX285its very difficult to bench in FSX - so its hard to see what you are really getting, but a GTX285 should be the fastest out of all the Nvidia solutions