'System.OutOfMemoryException' was thrown

[KrisS]

Woa, sorry about that. This is with NT 6.5 of course, and the /largeaddressaware hack - thus the 4+ day optimization duration. I had been reading too much NT7 pre-release info I guess. I apologize for the confusion.

Sadly one of my new memory sticks failed and it BSOD'd during the optimization. Back to 4GB and a big page file for now...

[NinjaTrader_Dierk]

Thanks for clarification

[paulg]

/LARGEADDRESSAWARE with NT/ 64 bit OS: only 2.4 Gb?

Here is some clarification: Applying LARGEADDRESSAWARE on NT.exe (which we're doing for NT7) makes no different on 32bit Windows (unless you would enable your 32bit Windows, which we don't recommend since it might introduce other non NT related issues). However, it makes a big difference as the 32bit NT7.exe is run on 64bit Windows. Then up to 2.5GB RAM could be used (according our findings).

According to http://msdn.microsoft.com/en-us/library/aa366778.aspx the NT7 32 bit limit with the /LARGEADDRESSAWARE set should be 4 Gb under 64 bit Windows.

Why you affirmed that even with the NT7 running w/ 64 bit Windows, the limit is at 2.5 Gb, giving only 500 Mb advantage vs. the 32 bit OSes?

[NinjaTrader_Dierk]

This is what Microsoft states in their docs (sorry, don't have a link at hand). Without that switch it would be around 1.5GB.

[paulg]

...strange: apparently MS deals with a 2.5 Gb vs. 4 Gb limits 'indifferently' with its own docs

[NinjaTrader_Dierk]

Not strange at all: you are referring to the process address space limit which are correct as per your statements. The usable address space for a .NET app is way smaller (see MS docs).