Being curious about the use of memory in FSX I loaded a free memory optimizer program (http://www.wincleaner.com/)that also displayed memory in use, free memory, virtual memory in use and free virtual memory as well as CPU usage. Watching these parameters while in-flight with the default Cessna and autopilot on was very informative. The system was low end:AMD 2ghz (real clock speed)Radeon 9800SE with 128mb1 gb ram I was not interested in FPS unless they became very good or very bad. They averaged 30fps in this instance with max mesh sliders, minimum terrain, no water effects, simple clouds (few),textures at 1m, no autogen, and normal scenery objects. First the bottom line in THIS ENVIRONMENT was that FSX never used more than 49% of the 1gb memory. I operated with a small window, a full window, and a 3d full screen. I also changed the view by panning, used the VC and 2D panels, as well as right wing and top down. As I type this I have the "optimizer/parameters program and notepad on screen atop FSX. 30 FPS... 49% of memory used 528mb free... At no time while "fiddling around", as I would during a typical flight, was there any extreme memory activity. I thought that there was what is known as a memory leak (failure to release unneeded memory) but at 49% of memory used FSX stopped consuming memory and began a management process that involved the virtual memory which was maintained at 73% free virtual space. Thus you can conclude that once FSX had all of the needed textures in memory it maintained a stable environment. Rapidly panning in a 360 produced no disk activity which indicated that FSX had all of the textures it needed in memory. I began this exercise with FSX paused in window mode but minimized. I used the memory tool to optimize memory which appeared to free much of the memory allocated to FSX. This was shown when I unpaused FSX and it began extensive disk activity and consumption of memory while loading textures it needed to satisfy the viewing area. During this process I panned around in the VC and had some pauses as FSX appeared to find textures missing from a table, marked them as needed, and then continued with the pan. As mentioned above, once FSX had all of the needed textures it stabilized memory usage and settled onto a 30fps display. So the question is - how much of a role does more memory play? Well I turned on the "dreaded" autogen at a max slider. It grabbed 20% more memory and dropped the FPS from 30 to 10fps. I now had 278mb of free memory remaining. Obviously I was FPS limited by the video card and the CPU. As I panned in a 360 the memory gradually dropped to the 278 level. I next turned on detailed clouds with max sliders and the free memory dropped to 19% (186mb). My FPS were down to 9.Finally I turned on traffic with all max sliders. This reduced free memory to 10%(87mb) and 5fps. A quick 360 pan placed the free memory at 5%. During all of this some things ended up in virtual memory as about 400mb were used there. This could continue with more and more combinations. However, it indicated (I think, or in my humble opinion (IMHO)) that in my system the video card and the CPU were the main deficiencies. I would also see the need for more memory if I wanted to use all of the features I paid for. If I would increase the terrain distance the memory usage would be leave no free memory. Doing this caused flashing display, etc. FSX did try with its "artificial intelligence" to compensate for my greed by reducing the global texture (not indicated in the slider).This was informative for me. Unfortunately, Christmas is past and Santa's wallet is low....Regards,Dick Boley

Now add a good add-on like the upcoming LVL-D or PMDG, ActiveSky, FS2 Crew etc...Cheers,-Paul

Just an added note - if you extend the terrain detail to maximum then memory usage steadily climbs. One gb is not sufficient at this setting (old 8mips value).Addons would be nice but there is a big cost coming, for me, when DirectX10 appears. I am sure the video cards will be PCIe which menas a new motherboard and a new video card. Probably $400 minimum. Then a new CPU is needed - 2ghz just not enough. Another $200. I like photo real scenery so I will probably need SATA $150 disks as well. And finally there is the need for the 2gb of fast memory $200. Might as well get a shiney new case with multiple fans to cool all of this "cool, awsome, kickass, way out & far out" stuff $100. Maybe I can justify the lower heating bills here in the Northeastern USA as an offset.Regards,Dick Boley