9/27/2024: Since the release of the Intel® oneAPI HPC Toolkit, Intel has been delivering two Fortran compilers: IFORT and IFX. IFX is a new development, and Intel announced last year that it would stop developing IFORT at the end of 2024. We took this as an opportunity to compare the runtime performance of both compilers, referring to the benchmarks we created in 2019 together with QT software GmbH (Germany). We use the same Fortran test programs and the same PC with the same equipment (although the operating system has received a few updates in the meantime). Since we also tested the IFORT from 2019 back then, we repeated the tests with this 5-year-old compiler. Here are our results for the three 64-bit compilers under Windows:
| Benchmark / Compiler | IFORT 2019.0.5 | IFORT 2021.13.1 | IFX 2024.2.1 | Arithmetic Mean |
| ac | 3.44 | 3.49 | 3.7 | 3.54 |
| aermod | 5.88 | 5.7 | 4.58 | 5.39 |
| air | 1.3 | 1.25 | 1.16 | 1.24 |
| capacita | 9,97 | 9.87 | 9.97 | 9.94 |
| channel | 45.26 | 45.01 | 51.32 | 47.20 |
| doduc | 5.53 | 5.55 | 5.48 | 5.52 |
| fatigue2 | 31.4 | 31.2 | 17.19 | 26.60 |
| gas_dyn2 | 23.95 | 22.97 | 26.23 | 24.38 |
| induct2 | 19.05 | 18.94 | 14.08 | 17.36 |
| linpk | 2.58 | 2.54 | 2.48 | 2.53 |
| mdbx | 3.45 | 3.43 | 3.54 | 3.47 |
| mp_prop_ | 31.56 | 31.87 | 28.88 | 30.77 |
| nf | 3.64 | 3.62 | 3.72 | 3.66 |
| protein | 13.44 | 13.44 | 13.81 | 13.56 |
| rnflow | 6.8 | 6.79 | 5.88 | 6.49 |
| test_fpu2 | 18.22 | 18.52 | 16.93 | 17.89 |
| tfft2 | 23.36 | 23.05 | 24.34 | 23.58 |
| Total | 248.83 | 247.24 | 233.29 | 243.12 |
Note: Currently (i.e. with version 2024 Update 2) Intel delivers the IFORT in version 2021.13.1 and the IFX version 2024.2.1.
| Commands: | IFORT %n.f90 /fast /link /stack:64000000 |
| IFX %n.f90 /fast /link /stack:64000000 |
When comparing the two IFORT versions, one can see a slight increase in performance and, on the other hand, that the IFX produces faster code than IFORT in just over half of the tests.