In an effort to bump up my frame rates in my 2003 system I replaced the GeForce FX5900 128 MB AGP with a GeForce 6800 GT OC 256 MB. MemStatus showed my old 128 MB card's video memory peak at 99%.I use an accurate benchmark and found that the default Cessna 172 got 30 fps with both cards. To my surprise, the Aeroworx King Air lost 4 fps with the new card. The 6800's 3dmark05 shows the card to be 5 times faster than the FX5900.I know FS is CPU bound but I wasn't expecting zero improvement. My primary questions are:1) Does this make any sense at all? Would this result be expected?2) Where is the bottleneck in my system?3) What can I do to take advantage of this new card's power?My system:AMD Athlon XP, 2200 MHz (11 x 200) 3200+ Barton (End of the line, no upgrade possible for that socket)Motherboard: Shuttle AN35(N) UltraChipset: nVidia nForce2 Ultra 400 FSB running 2x 200MHz (400MHz data rate) 768 MB (PC3200 DDR SDRAM)**************Other BIOS information:Sisoft Sandra2000 shows my AGP as:Version 3.00Current Data Transfer Rate 1xMax Data Transfer Rate 2xSide Band Enabled NoSide Band Support YesFast-Writes Enabled No(I don't understand the transfer rate 1x

Your CPU and old video card were well balanced. With the new video card you are now CPU bound. The one thing (and it's important) that we gain by throwing more video card at FS is image quality. Your experience is proof positive that FS requires a balanced system... CPU, video card, memory, system bus, etc.Regards,Greg

Hmmm...I got the same video card for a much older system - it was a PIII 500, which I upgraded to a Tualatin (celeron?) 1.2 ghz... After upgrading, my performance and image quality increased, especially image quality, as Greg suggests. I was able to pretty much max out all hardware - dependent effects.That said, I'm still getting only about 15 fps average.---Andrew

>Your experience is proof positive that FS requires a balanced>system... CPU, video card, memory, system bus, etc.I wish I knew more about Flight Simulator's programming architecture so I could tell if more RAM might open up the bottleneck.How about it? Would going from 768 MB to 1 or 2 GB open up some headroom for the new card or is it all slowing down at the processor?

When you upgraded the video, did you uninstall and do a clean to remove all traces of the old drivers? Could be there's a not-quite-compatible piece of the old driver setup still lurking in there. The 1x xfer speed looks odd to me.Also, the 6800 is a much more power-hungry board...is your power supply up to the task of pushing an overclocked 6800?768MB of RAM is a bit on the low side for a WinXP system, but more is not likely the key to this problem.RegardsBob ScottATP IMEL Gulfstream II-III-IV-V L-300Santiago de Chile

> The 1x xfer speed looks odd to me.Yeah, this exercise helped me discover that I hadn't loaded the chipset drivers when I installed this new drive. Loading the drivers gave me a nice boost in frame rate.I'm getting ready to test the old card again and I'll report if the old FX5900 is still faster or equal to the new 6800 GT.

The 6800 should be considerably faster...I replaced an FX5600 with a 6800 Ultra and it simply kicked a$$ in comparison.CheersBob ScottATP IMEL Gulfstream II-III-IV-V L-300Santiago de Chile