I used Filemon to troubleshoot FS tonight. For those who don't know about filemon, it's a small application that tracks file system activities real time. When I use it with FS, I can see in real time what files FS9.EXE tries to access. It helped me detect a couple of missing effect files that FS9.EXE infinitely tried to locate, hence causing significant FPS drop. After I fixed the problem I happened to load up PMDG737 and I noticed when I am in 737 VC, FS9.EXE uses over 50% of the time accessing two font files over and over and over again. they are LUCON.TTF and QUARTZ.TTF. FS9.EXE just keeps opening, quering and closing those files. I then tried about every other addon aircraft I have, this only happens with 737 VC. The 737 VC performance actually is not bad on my computer. But if we want to be totally technical, the infinite and non-stopping access to font files has gotta be for a cost of system resource and performance...more or less.Just want to share my observation here.Jason Zhang

Jason,Are you saying that if one uses the VC rather than 2D, there will be a reduction in the frame rate ?If yes, is the reduction significant?Stanner

Well yes and no. In general, VCs give lower performance than 2D panels. That's about true with every aircraft. Whether the reduction is significant or not really depends on your computer specs., add on aircraft and your FS setup, etc. In my particular case, the reduction with PMDG 737 is not significant. But what I was saying was much more specific. If you go to the general forum you'll finding an estensive thread talking about Frame rate dipping. When we monitor real time file system activities we can observe in great details what FS is doing...what files it opens and what register entries it accesses. What I was saying was that FS9.exe opens and closes two font files non-stop when I am in the 737 vc. This doesn't happen with any other aircraft I have. As I said, the 737 vc performance is actually not that bad on my computer, but at the same time I wonder if technically such extensive file activites are absolutely necessary or free of hitting performance more or less.I also read a thread that someone noticed the 747, when loaded, never quits looking for an entry in the regiestry that doesn't exist. But I can't seem to find that thread anymore.Jason