Is there a way to increase the length of time textures reside in ram? I seem to remember a registry tweak for this maybe? If so this could be a huge improvement in FSX when switch views, particularly when switching back to the VC.

I thought Win7 kept the data cached in the RAM as long as there is enough available RAM. So it doesn't have to read it from the hard drive again.

Indeed that's the way I understood how memory works. If you switch to an outside view or 2D view, then right back to the VC, it loads instantly, I'm assuming because the textures are in ram. So I have to assume that when you are away from the VC for long enough and it loads slowly when yo return, it would be because the textures have been released from ram. What else could be the reason for the difference in load times?I asked the question a few years ago and one of the gurus replied with a registry value to edit if I remember correctly. Don't remember which site I was on.

How long is "long enough"? Believe using SSD would also be a way to solve the problem.

There is only a short amount of time - less than 10 seconds - that you can switch away from and back to the VC and not have the slow load time (on detailed addons obviously). That's what I meant by "away for long enough".No SSD for me; That has to be the worst "performance" gain to price ratio in the history of the PC. But that's another topic.I don't know yet how relevant this is yet but I think there may be a registry setting that determines the point at which windows de-commits memory. If this does what I think it does (I doubt it) maybe this threshold should be raised.

I think it's more an issue of how long before the textures are no longer kept in VRAM. I have been doing some experimentation with disk caching to RAM using 10GB of fast 2133MHz CAS 9 RAM assigned to a secondary cache (FancyCache beta version). The secondary cache is rarely hit once FSX loads, suggesting to me that FSX does a decent job of keeping the textures it's using alive in the primary Windows file cache. That said, if you look away for a time, then load the VC again, it's obvious from the relatively slow bounceback that the textures are having to load again, but the disk cache is not being hit--the delay is loading the textures from where they're already being kept in RAM into VRAM--via the PCIe bus. This is congruent with what Phil Taylor told us some time back about PCIe being a limiting factor in FSX.The secondary cache is a wonderful thing to have if you have to get in/out of FSX repeatedly, such as when doing development work or tweaking. Once FSX has been loaded once, I can get from Win 7 back to the aircraft load screen in around 20 seconds, despite a large add-on scenery and utility collection and hundreds of AI aircraft that all have to be loaded. FancyCache allows selection of the cache algorithm used--least recently or least frequently used. With a 10GB cache (out of 16GB total) and LRU selected, pretty much everything FSX accesses remains in the secondary disk cache for the entire sim session. Again--great for reloads, not much help for faster screen refreshes.

If we are talking only after a few seconds the textures won't for sure already be evicted from RAM. But as Bob says, they are probably evicted from VRAM. If only MS could be kind enough to develop a 64bit version of FlightSimulator. But we can unfortunately only dream.

The secondary cache is a wonderful thing to have if you have to get in/out of FSX repeatedly, such as when doing development work or tweaking. Once FSX has been loaded once, I can get from Win 7 back to the aircraft load screen in around 20 seconds.

Do you really need the secondary cache for that? My experience is that windows out of the box is good at keeping things cached after they have been loaded once, or even superfetched from a HDD before you load it if you have your computer on a while. But I don't have anything close to the amount of add-ons as you have.

Not sure if this applies to your situation, but, do you have the "HIGHMEMFIX=1" in your FSX.CFG?