| Some explanations on NAS Parallel Benchmarks 3.3 - Serial version |
| ----------------------------------------------------------------- |
| |
| The serial version of NPB3.x (NPB3.x-SER) is based on NPB2.3-serial |
| with a number of improvements (see Section 3 below) and added with |
| two new benchmarks (UA and DC). |
| |
| For problem reports and suggestions on the implementation, please contact |
| |
| NAS Parallel Benchmarks Team |
| npb@nas.nasa.gov |
| |
| |
| 1. Compilation |
| |
| NPB3.3-SER uses the same directory tree as NPB2.3. |
| Before compilation, one needs to check the configuration file |
| 'make.def' in the config directory and modify the file as necessary. |
| If it does not (yet) exist, copy 'make.def.template' or one of the |
| sample files in the NAS.samples subdirectory to 'make.def' and |
| edit the content for site- and machine-specific data. Then |
| |
| make <benchmark> CLASS=<class> [VERSION=VEC] |
| |
| <benchmark> is one of (BT, SP, LU, FT, CG, MG, EP, IS, UA, DC) and |
| <class> is one of (S, W, A, B, C). Although Classes D and E are also |
| defined for a number of benchmarks, the memory requirement and |
| execution time likely exceed what most of the single processor |
| systems can support. |
| |
| Classes C, D and E are not defined for DC. |
| Class E is not defined for IS and UA. |
| |
| The "VERSION=VEC" option is used for selecting the vectorized |
| versions of BT and LU. |
| |
| Class D for IS (Integer Sort) requires a compiler/system that |
| supports the "long" type in C to be 64-bit. As examples, the SGI |
| MIPS compiler for the SGI Origin using the "-64" compilation flag and |
| the Intel compiler for IA64 are known to work. |
| |
| In order to build the class E version of CG, the integer type |
| needs to be promoted to 64-bit, which is usually done through |
| compilation flag (such as "-i8" for FFLAGS in config/make.def). |
| |
| To build a suite of benchmarks, one can create the file |
| "config/suite.def", which contains a list of executables to build. |
| Each line in the file contains the name of a benchmark and the class, |
| separated by spaces or tabs (see suite.def.template for an example). |
| Then |
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| make suite |
| |
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| ================================ |
| |
| The "RAND" variable in make.def |
| -------------------------------- |
| |
| Most of the NPBs use a random number generator. In two of the NPBs (FT |
| and EP) the computation of random numbers is included in the timed |
| part of the calculation, and it is important that the random number |
| generator be efficient. The default random number generator package |
| provided is called "randi8" and should be used where possible. It has |
| the following requirements: |
| |
| randi8: |
| 1. Uses integer*8 arithmetic. Compiler must support integer*8 |
| 2. Uses the Fortran 90 IAND intrinsic. Compiler must support IAND. |
| 3. Assumes overflow bits are discarded by the hardware. In particular, |
| that the lowest 46 bits of a*b are always correct, even if the |
| result a*b is larger than 2^64. |
| |
| Since randi8 may not work on all machines, we supply the following |
| alternatives: |
| |
| randi8_safe |
| 1. Uses integer*8 arithmetic |
| 2. Uses the Fortran 90 IBITS intrinsic. |
| 3. Does not make any assumptions about overflow. Should always |
| work correctly if compiler supports integer*8 and IBITS. |
| |
| randdp |
| 1. Uses double precision arithmetic (to simulate integer*8 operations). |
| Should work with any system with support for 64-bit floating |
| point arithmetic. |
| |
| randdpvec |
| 1. Similar to randdp but written to be easier to vectorize. |
| |
| |
| 2. Execution |
| |
| The executable is named <benchmark-name>.<class>.x and is placed |
| in the bin subdirectory (or in the directory BINDIR specified in |
| make.def, if you've defined it). NPB3.3-SER can be run as regular |
| executables without additional settings. For example: |
| |
| bin/bt.A.x > BT.A_out |
| |
| It runs BT Class A problem and the output is stored to BT.A_out. |
| |
| Each benchmark includes a set of additional timers for profiling purpose |
| (reporting timing for selected code blocks). By default, these timers |
| are disabled. To enable the timers, create a dummy file 'timer.flag' |
| in the current working directory (not necessarily where the executable |
| is located) before running a benchmark. |
| |
| |
| 3. Notes on the implementation (NPB3.0-SER) |
| |
| 3.1 BT |
| |
| This version is optimized for memory performance. It uses much less |
| memory than the original version due to the size reduction of working |
| arrays. |
| |
| Serial performance in comparison with the original NPB2.3-serial. |
| ---------------------------------------------------------------------- |
| Machine (Speed) Class NPB2.3-serial NPB3.0-SER |
| Origin2000 (250MHz) A 2162.4(77.82) 1075.2(156.51) 50.3% |
| T3E (300MHz) W 218.1(35.39) 117.0(65.95) 46.4% |
| A ~5285.5(31.84) 2836.5(59.33) |
| SGI R5000 (150MHz) W 549.8(14.04) 265.0(29.13) 51.8% |
| PPro (200MHz) W 316.8(24.36) 121.2(63.69) 61.7% |
| ---------------------------------------------------------------------- |
| -- memory usage (Class A): |
| NPB2.3 - 323MB, PBN - 46MB |
| ---------------------------------------------------------------------- |
| |
| 3.2 SP |
| |
| This version is optimized for memory performance. The smaller dimension |
| in U and RHS was moved to the inner-most, which gives better cache |
| performance. However, the code is not as friendly to vector machines as |
| the original version. |
| |
| Serial performance in comparison with the original NPB2.3-serial. |
| ---------------------------------------------------------------------- |
| Machine (Speed) Class NPB2.3-serial NPB3.0-SERerial |
| Origin2000 (250MHz) A 1478.3(57.51) 971.4(87.52) 34.3% |
| T3E (300MHz) A 3194.3(26.61) 1708.3(49.76) 46.5% |
| SGI R5000 (150MHz) W 1324.2(10.70) 774.1(18.31) 41.5% |
| PPro (200MHz) W 758.9(18.68) 449.0(31.57) 40.8% |
| ---------------------------------------------------------------------- |
| -- memory usage (Class A): |
| NPB2.3 - 82MB, PBN - 48MB |
| ---------------------------------------------------------------------- |
| |
| 3.3 LU and LU-hp |
| |
| LU is essentially the same as the original NPB2.3-serial. |
| It is a good starting point for a pipeline implementation. |
| |
| LU-hp contains a hyper-plane implementation of the SSOR algorithm. |
| The default version is 3-D hyper-plane and has worse cache performance |
| than LU. Six relevant routines for a 2-D hyper-plane (wave-front) |
| implementation are included in the subdirectory 'ver2'. |
| |
| Some of the timings on a single processor: |
| ---------------------------------------------------------------------- |
| Class A LU LU-hp-3D LU-hp-2D |
| Origin2000 (250MHz) 1389.4(85.87) 1605.1(74.32) 1325.1(90.03) |
| ---------------------------------------------------------------------- |
| |
| 3.4 FT |
| |
| Summary of changes from NPB2.3-serial |
| |
| - Reduce the use of memory for big arrays by 1/3 |
| - Random number generator is made parallelizable |
| |
| 3.5 CG, MG |
| |
| Except for removal of some working buffers (used in the MPI |
| program), the implementation has the same structure as the |
| NPB2.3-serial. |
| |
| 3.6 EP |
| |
| It has the same implementation as in the original NPB2.3-serial. |
| |
| 3.7 IS |
| |
| An extra array copy in the iteration loop was eliminated in the new |
| version. This improved performance by about 35% on a CLASS A problem |
| on Origin2000 (195MHz). |
| |
| Old version (NPB2.3-serial)- |
| Time in seconds = 9.06 |
| Mop/s total = 9.25 |
| |
| New version (NPB3.0-SER)- |
| Time in seconds = 5.89 |
| Mop/s total = 14.23 |
| |
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| 3.8 Timers |
| |
| NPB3.x-SER includes additional timers in the seven Fortran |
| benchmarks. To activate these timers, create a dummy file |
| 'timer.flag' in the directory where the program is to run. |
| |
