Lahey Support
08-15-2003, 01:19 AM
I think one of the keys here is the use of Powerstation 4.0. Here at my
company we had PS 4.0 and Lahey 3.5. A structural analysis DLL was made
from legacy fortran 77 code first with Powerstation and then 4 months later
with LF90. Swapping out the 2 DLL's indicated that Lahey had a factor of 4
speed advantage over powerstation and maintained a full trace back table if
the code crashed.
Now I cannot comment on the effects of compile options used to compile under
Powerstation and Lahey. (I do not have the original project files that
generated the DLL using powerstation)
One Comment I have is that LF903.5 created slower executibles then
F77L3/EM-32 on mathematically intensize code.
I will agree that if the various FORTRAN compiler venders cannot keep a
speed advantage over C++ they will looses there client base quickly.
Rick Carlstrom
Head of Programming
Nichols Advanced Marine Enterprises.
-----Original Message-----
From: Ching-Kuang Shene [address removed]
Sent: Wednesday, February 10, 1999 3:16 AM
To: [address removed]
Subject: [LF] Fortran 90 vs C++ Valarrays
Hi all,
In a recent article "Comparing Fortran 90 and C++ Valarrays" in C/C++ Users
Journal, the authors (Shyam Bhat and B. Arun) compared MSVC++ 5.0 and
Microsoft PowerStation v 4.0 with their finite element method program on
a Pentium 150MHz with 48MB. Here is their result:
Test # of eqn matrix size F90 C++
---- -------- ----------- ----- -----
1 4353 520,000 3,244 3,095
2 3492 320,000 1,612 1,532
3 2088 180,000 921 871
4 987 65,000 265 250
The "matrix size" is in # of doubles and the timing values are in msec.
The authors' conclusion is that C++ has a speed advantage of 5%.
Note that valarrays is a C++ STL implementation.
Does anyone out there have similar results? C++ is a complex language and
STL in general in not very efficient. It is strange that C++ with valarrays
can beat Fortran. There are certainly a lot of unknown factors such as
the quality of PowerStation v 4.0 and the testing program, the switches used
for the compilation and others. If LF90/LF95 cannot maintain a speed lead,
many engineers/scientists will jump to C++ quickly. I am afraid that this
is happening in many places, including this university.
CKS
company we had PS 4.0 and Lahey 3.5. A structural analysis DLL was made
from legacy fortran 77 code first with Powerstation and then 4 months later
with LF90. Swapping out the 2 DLL's indicated that Lahey had a factor of 4
speed advantage over powerstation and maintained a full trace back table if
the code crashed.
Now I cannot comment on the effects of compile options used to compile under
Powerstation and Lahey. (I do not have the original project files that
generated the DLL using powerstation)
One Comment I have is that LF903.5 created slower executibles then
F77L3/EM-32 on mathematically intensize code.
I will agree that if the various FORTRAN compiler venders cannot keep a
speed advantage over C++ they will looses there client base quickly.
Rick Carlstrom
Head of Programming
Nichols Advanced Marine Enterprises.
-----Original Message-----
From: Ching-Kuang Shene [address removed]
Sent: Wednesday, February 10, 1999 3:16 AM
To: [address removed]
Subject: [LF] Fortran 90 vs C++ Valarrays
Hi all,
In a recent article "Comparing Fortran 90 and C++ Valarrays" in C/C++ Users
Journal, the authors (Shyam Bhat and B. Arun) compared MSVC++ 5.0 and
Microsoft PowerStation v 4.0 with their finite element method program on
a Pentium 150MHz with 48MB. Here is their result:
Test # of eqn matrix size F90 C++
---- -------- ----------- ----- -----
1 4353 520,000 3,244 3,095
2 3492 320,000 1,612 1,532
3 2088 180,000 921 871
4 987 65,000 265 250
The "matrix size" is in # of doubles and the timing values are in msec.
The authors' conclusion is that C++ has a speed advantage of 5%.
Note that valarrays is a C++ STL implementation.
Does anyone out there have similar results? C++ is a complex language and
STL in general in not very efficient. It is strange that C++ with valarrays
can beat Fortran. There are certainly a lot of unknown factors such as
the quality of PowerStation v 4.0 and the testing program, the switches used
for the compilation and others. If LF90/LF95 cannot maintain a speed lead,
many engineers/scientists will jump to C++ quickly. I am afraid that this
is happening in many places, including this university.
CKS