64-bit programming

[gjakeman]

I am a long term Lahey user but am looking at moving to a computer with 64-bit processor and operating system as my programs need to address more RAM than the standard 32 bit architecture allows. I was under the impression that I had to move to a different compiler (eg Absoft or Intel), but on rereading the LF95 specs I am wondering if that is necessary.

In the specs for LF95 v5.7 it says that the "External file size increased to 2**64 bytes".

My questions are:
Does LF95 support 64-bit programming?
Can I use any 64-bit operating system (eg Windows 2003)?
Can I use an Itanium processor or AMD processor, or does it not matter?

[tzeis]

We currently do not support 64 bit programming for the memory address space that you require.
You should be able to use the compiler on a 64 bit Windows OS.
You will probably not get satisfactory results from the Itanium system. The AMD system is compatible, and you should see some performance improvements, but the current addressing limits of the compiler will remain.

[djmiller]

They're in the current Athlon 64, Opteron, and Athlon FX, now, and will be added to new Intel Xeon chips that are supposed to ship by the end of the year.

The portland group compilers are supposed to fully support the AMD64 instructions and address space, but we're more comfortable staying with a family of compilers with which we're familiar.

Any idea how long we'll have to wait?

[monahh]

I'm completely agree with previous speaker.
We have been using Lahey for several years, now our next calculation server will be one of 64-bit (AMD Opteron or Xeon 64), and due to Lahey is not going to support them, or at least doesn't provide any information I start thinking about migrating to PGI or Absoft.

Any news about 64-bit support?

[tzeis]

Starting yesterday (10/22) we have started offering a 64 bit compiler that runs on an Opteron system, using the SuSE 9 Linux operating system. Lahey provides technical support. You can contact sales for an evaluation copy. See our announcement for more details: <nobr><a href="http://forum.lahey.com/showthread.php?p=10701#post10701">PathScale Announcement</a></nobr>