Hello, I know that Prepar3D runs really well on Windows 7 64 bit. I have a basic technical question. Is there a limitation of memory use for Prepar3D (32bit application) running on 64 bit Windows 7 ?
Thank you.
Juraj
Memory limit on 64bit Windows 7 for 32 bit Prepar3D ?
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Beau Hollis
- Lockheed Martin
- Posts: 2452
- Joined: Wed Oct 06, 2010 3:25 pm
Yes, somewhere between 2GB and 4GB. All 32-bit apps are limited to at-best 4GB of memory based on the size of memory pointers used. On a 32-bit OS, you'll be limited to at-best 2GB because the OS will reserve memory, as will your video card and other devices. I'd have to do some digging to see if we are setting the large address aware build flags properly to enable >2GB in a 64 bit OS, but I think I've seen my P3D memory usage go up to 2.5GB before. (albeit in a dev build that was leaking memory).
In any case, I can almost guarantee that P3D will have access to more memory in a 64 bit OS that it will in a 32 bit OS.
Beau
In any case, I can almost guarantee that P3D will have access to more memory in a 64 bit OS that it will in a 32 bit OS.
Beau
Beau Hollis
Prepar3D Software Architect
Prepar3D Software Architect
If I had 1 cent for every time I have seen people ask this, I'll be a rich as Bill Gates !!!
To add to what Beau said, you can do a little better than the 2 gig limit on a 32 Bit OS. by using the 3 gig switch.
Optimum I have found by trial and error is about 2.5 gigs allocated to application. The extra 500 Megs really can make a big difference.
You still need to leave 1.5 Gigs for the Kernel.
I believe in a 64 bit OS, you can do a little better, as the Kernel is outside the 4 GiG address boundary of the 32 bit address space,
The video memory and hardware still sits in the 4 meg 32 bit address address space, but you can force the allocation of more than the standard 2 gigs to the application.... although I have not tried it with a 64 bit OS. I also believe that some modern motherboards can even Map the video to be outside the 32 bit applications address space ???
I am not 100% sure on any of the above as it is based on what I have read on the Internet, and not practical experience.
Hopefully someone else can confirm or deny ..
There is a LOT of info about all of this on the Internet, as it applies to FSX, which, once again, I believe is also similarly aplicable to P3D.
When and if there is a 64bit version of P3D, then limited address space issues will becone a dim distant memory !!!
(as will all those FSX 32 bit addons )
To add to what Beau said, you can do a little better than the 2 gig limit on a 32 Bit OS. by using the 3 gig switch.
Optimum I have found by trial and error is about 2.5 gigs allocated to application. The extra 500 Megs really can make a big difference.
You still need to leave 1.5 Gigs for the Kernel.
I believe in a 64 bit OS, you can do a little better, as the Kernel is outside the 4 GiG address boundary of the 32 bit address space,
The video memory and hardware still sits in the 4 meg 32 bit address address space, but you can force the allocation of more than the standard 2 gigs to the application.... although I have not tried it with a 64 bit OS. I also believe that some modern motherboards can even Map the video to be outside the 32 bit applications address space ???
I am not 100% sure on any of the above as it is based on what I have read on the Internet, and not practical experience.
Hopefully someone else can confirm or deny ..
There is a LOT of info about all of this on the Internet, as it applies to FSX, which, once again, I believe is also similarly aplicable to P3D.
When and if there is a 64bit version of P3D, then limited address space issues will becone a dim distant memory !!!
(as will all those FSX 32 bit addons )
The biggest advantage of an eight 8GB hardware and a 64bit system is that the extra 4 GB are available as disk cache - every file read once can remain in memory and does not need to be read again from disk, this adds a lot of smoothness. So in the ned of these 8 GB, 1 is used for the OS, up to 3 for FSX itself and 4 for all the files FSX reads, so in the end you can have all but a little reserve filled.
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CaseyJParker
- Posts: 39
- Joined: Tue Feb 28, 2012 10:34 pm
Quote:
Quote from Burkhard on November 29, 2011, 09:27
The biggest advantage of an eight 8GB hardware and a 64bit system is that the extra 4 GB are available as disk cache - every file read once can remain in memory and does not need to be read again from disk, this adds a lot of smoothness. So in the ned of these 8 GB, 1 is used for the OS, up to 3 for FSX itself and 4 for all the files FSX reads, so in the end you can have all but a little reserve filled.
How can you go about configuring P3D to use a memdisk as cache?
Windows 7 does this for free...
If you open a large file the first time after boot and then again you will see this.
Another point I see ist that simconnect clients do not add to the 3?G P3D may use - I had a memory leak in one (compiled for 32bit) and it grew to 2G alone still working perfect, then it ceased working.
If you open a large file the first time after boot and then again you will see this.
Another point I see ist that simconnect clients do not add to the 3?G P3D may use - I had a memory leak in one (compiled for 32bit) and it grew to 2G alone still working perfect, then it ceased working.
