FSX sp2 patch had an option in it to allow the exe to use 4gb or more

Thanks for your answers.I have no traffic addons installed because I'm flying online. :( Just checked my Ultimate Terrain versions, they are all up to date.I will do a longer testflight at weekend, my short flights during the week have been successful with the standard LOD of 4.5 :(

FSX sp2 patch had an option in it to allow the exe to use 4gb or more

32bit programs use 32bit libraries - you cannot address more than4G of memory because you cannot make a memory address > 4Gwith a 4byte word. FSX cannot utilise more than 4G RAM as it isa 32bit software. To convert to 64bit software it will need tobe recompiled with the right 64bit run time libraries - which mayhave not yet been written, and will require a some code refactoring.Bet this will not format - straight from windows documentation,.Memory type Limit in 32-bit Windows User-mode virtual address space for each 32-bit process 2 GBUp to 3 GB with IMAGE_FILE_LARGE_ADDRESS_AWARE and 4GT Limit in 64-bit Windows2 GB with IMAGE_FILE_LARGE_ADDRESS_AWARE cleared (default)4 GB with IMAGE_FILE_LARGE_ADDRESS_AWARE setWindows is one better than Linux in this regard. You either get "wrong architecture" or error "loading shared library" if you run 32bit software on a 64bit OS.Edit : here are the physical (real memory limits) for the different OS - ie if you add morethan this amount of RAM it will be ignored 32bit 64bitWindows 7 Ultimate 4 192Windows 7 Enterprise 4 192Windows 7 Professional 4 192Windows 7 Home Premium 4 16Windows 7 Home Basic 4 8Windows 7 Starter 2 2

Bet this will not format - straight from windows documentation,.Memory type Limit in 32-bit Windows User-mode virtual address space for each 32-bit process 2 GBUp to 3 GB with IMAGE_FILE_LARGE_ADDRESS_AWARE and 4GT Limit in 64-bit Windows2 GB with IMAGE_FILE_LARGE_ADDRESS_AWARE cleared (default)4 GB with IMAGE_FILE_LARGE_ADDRESS_AWARE set

Regarding this I have another question.I want to replace my GTX280 with a GTX480 in the near future, if I'am right, memory of the GPU also belongs to virtual address space. That means applications like FSX have less than 500 MB they could use because of higher GPU memory (GTX280 = 1GB, GTX480 = 1,5 GB)Please correct me if I'm wrong.So in this case my virtual address space should be exhausted faster with a GPU with more memory and therefore I'll get the out of memory error faster.Let me quote MS concerning virtual address space usage and DX9:Every memory allocation, file mapping, or library that is loaded by an application consumes space in this virtual address space. When the application consumes all its virtual address space, any additional such operations fail. Although all applications should be coded to handle memory allocation failures, many applications do not recover correctly from such failures. Therefore, the programs may become unstable or stop responding after they recover from such failures.Existing games and other graphics applications frequently allocate virtual memory for a copy of the video memory resources that the application uses. The application uses this copy to restore the display quickly if the contents of video memory are lost. For example, the application uses this copy if the user presses ALT+TAB or if the user puts the computer in standby. Typically, the DirectX run time manages the copy on behalf of the application when the application creates a managed resource. However, an application can also manage the copy itself. The virtual memory that the copy uses is directly proportional to the video memory resources that the application allocates.A modern graphics processing unit (GPU) can have 512 MB or more of video memory. Applications that try to take advantage of such large amounts of video memory can use a large proportion of their virtual address space for an in-memory copy of their video resources. On 32-bit systems, such applications may consume all the available virtual address space. ...........If an application creates its own in-memory copy of its video resources, or the application uses DirectX 9 or an earlier version, the virtual address space contains the WDDM video memory manager's virtualized range and the application's copy. Applications that use graphics APIs that are earlier than DirectX 10 and that target GPUs that have large amounts of video memory can easily exhaust their virtual address space.The last phrase confirms my thoughts I think, I use DX9 mode in FSX with XP 64 bit, so no WDDM of Vista (SP1) or Win7 and no DX10 where MS changed this behaviour:With the introduction of DirectX 10 and Windows Display Driver Model (WDDM) in Windows Vista, it is no longer necessary for an application to maintain a copy of its resources in system memory. Instead, the video memory manager makes sure that the content of every video memory allocation is maintained across display transitions. For compatibility reasons, Windows Vista emulates "device lost" for DirectX versions that are earlier than DirectX 10 to make sure that no application-visible API behavior changes.

If you want to run higher LOD in this situation forget about BP=0, you will need to bump it up and find what works.Running Very High LOD with many of the same add-ons as you and BP=0 ALWAYS results in eventual oom and have had to run BP=4960. I plan on picking up a 485GTX in the fall when they come out and FORGET about BP=x altogether.

My autogen density is set to dense, David and yes I use Ultimate Terrain, ASE for weather and REX (1024 resolution) for clouds.I just finished my testflight over EHAM with a landing by night, switched several times between cockpit and outside view, also switched between windowed and fullscreen mode with a LOD_RADIUS of 4.5 and I didn't get the OOM problem.Maybe this was the key but I will test more on a flight of several hours when I have time to do so.I'll also increase TEXTURE_MAX_LOAD to 4096 and install REX textures in this resolution to see what happens then.If higher LOD_RADIUS is really the reason for OOM's I wonder that this has so much impact on usage of memory.

I have the same problem, constantky get OOM error, and I also have the LOD tweak, mine is set to 9.5, maybe this stands behind the problem? My texturemaxload is set to 4096, too. This OOM error only happens to me with the JS41, which I bought yesterday. The rest of my airplanes work fine even with LOD radius set at 9.5, but I will now test with standard LOD radius at 4.5.Hope it will help.Zsolt

Regarding this I have another question.I want to replace my GTX280 with a GTX480 in the near future, if I'am right, memory of the GPU also belongs to virtual address space. That means applications like FSX have less than 500 MB they could use because of higher GPU memory (GTX280 = 1GB, GTX480 = 1,5 GB)Please correct me if I'm wrong.So in this case my virtual address space should be exhausted faster with a GPU with more memory and therefore I'll get the out of memory error faster.

In 32bit windows, everything running could not address more than 4G, with the default program space being 2Gwith a modification to get about 3G. So this total 4G virtual address space was the total for absolutelyeverything - including graphics, programs and OS. So with 32 windows, you would reduce the available virtual memory for a program if you had large memory (multiple) graphics cards. Normally, the graphicscard memory "shadow" was in the 2G normally reserved for the OS - and not available to the program andyou can reduce this with a modification - but this would not play well with a large memory graphics card.In 64Bit windows you would normally get 4G to your program, but windows has accessto rediculus amounts of other addressible space since the total addressible space for 64bit pointers isabout 2T. Windows version restricts the physical addressible memory (the RAM in your computer) dependenton the OS version - this has nothing to do with the addressible space available to a program. So on 64bitcomputers you don't need to worry about the memory of you multiple graphics cards - it will not take anyaddress space (virtual memory) from your program. Regardless of your graphics card you will be able to access 2G (not set flag) or 4G (set flag) memory.

Thanks for your detailed information Tom.I will buy the GTX480 next week and hope to get some more performance under heavy weather, because the GTX280 has some problems if there are many clouds independent from cloud resolution of REX.@ freebird: Could you please explain the relation between BP=0, a higher LOD and OOM's more precisely to me?My thought was BP=0 can cause autogenspikes on some systems but has nothing to do with OOM's as well in combination with a higher LOD.