Ftn95 on Win XP X64 ?

Is ftn95 v4.80 compatible with Windows XP X64? I appreciate that it doesn't yet optimise compilation for a 64-bit environment, but does it at least run, build a 32-bit executable, which will then run and give exactly the same results for floating-point arithmetic as in Windows XP 32-bit?

If so, can a ftn95 compiled program make use of any of the memory above 2GB available on an XP x64 machine with 4GB RAM?

With thanks in advance, Andrew Smith London Analytics

OK, two Andrew Smiths, this could get confusing...

FTN95 will run and build programs that will quite happily run on WinXP 64bit. Regarding the question as to the comparison of results with a 32bit OS, I will check with the developer running XP 64, but I would be surprised if there were differences.

FTN95 compiled programs have the flag IMAGE_FILE_LARGE_ADDRESS_AWARE set in the executable header by default (when no debugging options are used), so should be able to use up to 4GB of address space as the space is not polluted as it is on 32bit systems.

Andrew

I run FTN95 on a 64 bit machine but so far I have only used 32-bit Windows XP. My guess is that it will run under Windows XP X64 and that this will make more memory available, with the potential of up to 4GB.

With a 32-bits machine and an operating system such as Windows XP, you can already get up to 3GB of memory by using a) the latest version of FTN95 and b) the /3GB switch in your boot.ini.

Then, by default, SLINK will give you 3GB of memory in (FTN95) release mode and 2GB in any of the (FTN95) debug modes. You can over-ride the defaults with SLINK commands 3GB and 2GB but 3GB with /UNDEF etc is not entirely safe because the UNDEFINED state is an address in the upper range.

On a 64 bit machine there is the potential for getting the full 4GB address space (in release mode) with both a 32-bit and a 64-bit operating system, since the operating system and everything else does not need to encroach upon the 4GB FTN95 address space. However, I have not tested this out.

If you want to test out FTN95 and do not have a licence, you could always run some test using the free personal edition to see how much memory becomes available.

I need to clarify/correct my last message.

On a 64 bit machine with the current FTN95, there is a potential

1. 4GB address space with a 64 bit operating system
2. 3GB address space with a 32 bit operating system.

Great stuff, thanks to my doppel 🆒 and to Paul for that. Should the project I'm planning actually happen, I'll post back here with any findings of note. Thanks for the reassurance that it's worth a crack.

If anyone's got any performance comparisons of memory-hungry arithmetic intensive FTN95 running on AMD 64 vs Intel 64, I'd be very keen to see it (before buying the hardware for this project).

Regards,

Andrew Smith London Analytics

(edit: forum name changed to help prevent any confusion) (2nd edit: follow-up thread starts here)