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Questions tagged [cray]

Cray Inc. is a supercomputer manufacturer based in Seattle, Washington. The company provides software targeting their hardware including compilers and MPI wrappers.

Cray Inc. is a supercomputer manufacturer based in Seattle, Washington. The company's predecessor, Cray Research Inc., was founded in 1972 by computer designer Seymour Cray. In 2000 the bulk of Cray Research was sold the Seattle based Tera Computer Company, with the later taking the brand of the former.

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How to get 100% CPU usage from a C program

This is quite an interesting question so let me set the scene. I work at The National Museum of Computing, and we have just managed to get a Cray Y-MP EL super computer from 1992 running, and we really want to see how fast it can go! We decided the…
bag-man
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Does anyone know where to get actual Cray PVP code?

I want to write a emulator for one of the older Crays, but I've run into a stumbling block. I can't seem to find any actual code for them. (Which kind of makes sense I suppose, most of them would have been used for defense and the like..) Does…
monocasa
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Could a Cray XK6 run a real-time raytracer?

I heard about Cray's new supercomputer -- the XK6 -- today, but I am a little confused about where the bottlenecks are. Is it in interconnec? Can an XK6 configured with, say, 500,000 16-core processors achieve a graphic fidelity comprable to Toy…
gonzo_taylor
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Gathering info about GASNet communicative operations in Cray Chapel

Working on a basic profiler which will gather start and finish time of GASNet communicative operations in Cray Chapel. Only idea which came in mind was to insert instructions in Chapel comm functions to get function call time. Is there any way to do…
dreamca4er
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How to get rank in aprun

I am trying to run a multi-node jobs with aprun. However, I couldn't figure out how to get the rank (or whatever that serves as the ID of each job) in bash environment. Like this simple job: aprun -n 8 -N 2 ./examplebashscript.sh How can I get the…
user4668442
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Fortran executable doesn't like command line input of integer

This code compiles and runs just fine under Intel and GNU: program simplarray implicit none real, allocatable, dimension(:,:,:) :: a character(len=32) :: cmdarg integer :: n = 0 call…
bob.sacamento
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Does Cray mpich have a 64 bit integer MPI variable?

I am using cray-mpich/7.4.0. When I do printf("Size:%d",sizeof(MPI_UINT64_T)); It print 4 instead of 8. Why is that? The cluster machine is 64 bit for sure. I have tried this with openmpi/1.10.2 on another cluster and that prints 8.
Abhishek
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Different number parameters calling C routine from FORTRAN 90

I am calling a C routine from a FORTRAN 90 code. All works fine, but I am wondering why and how when I call the C routine with less parameters that I should the compiler does not complain. What is the compiler doing here? I am using a Cray…
Manolete
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mpi: MPI_INIT_THREAD provided level of support

I am using openmp on a cluster. When I use MPI_INIT_THREAD with desired level of thread support as MPI_THREAD_MULTIPLE, the provided level is support is only 2. I do not know, whether I am doing some mistake or missing a compiler flag. On this…
user984260
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Running a mono app with the Cray aprun command

I've been able to get a C# mono program to run on my Cray machine by making a simple batch script and passing that to the aprun command. I'm experimenting with a very small file and I'm getting the output I'd expect... what I'm wondering is if…
Volvox
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MPI spawn and cray's aprun

Suppose I have a master program, which is basically a 1 rank mpi which uses MPI spawn to spawn 5 worker programs. Now, if I execute my master using the following command aprun -n 1 -N 1 master The total number of ranks after spawning will be 6.…
grok
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Using GNU parallel command with aprun command?

I am trying to run this on Cray XE6: aprun -n 1 sh -c 'parallel -j8 :::: s.txt' where in s.txt I have 16 lines like this: python hello.py > 01.out hello.py just prints hello. My script runs forever. And I am running it on one compute node which…
user2458189
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Intel compiler segmentation violation when compiling using -openmp and -ipo with Cray LibSci on Cray XC30

I am compiling a code that uses Cray LibSci numerical library for BLAS and LAPACK on a Cray XC30 system using the Intel compiler with the "-ipo" flag and including "-openmp" to compile OpenMP-enabled code. I see the following error for any code I…
AndyT
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Error when running VASP 5.3.5 on Cray XC30

When running VASP 5.3.5 on a Cray XC30 I see the following error: Rank 4 [Mon Jun 1 14:58:35 2015] [c1-0c0s2n0] Fatal error in PMPI_Allgatherv: Invalid buffer pointer, error stack: PMPI_Allgatherv(1235): MPI_Allgatherv(sbuf=0x49ead730,…
AndyT
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Obtaining current host name from Cray Fortran

Anyone knows how to get the current host name from a Cray Fortran program? I want basically the output of UNIX gethostname(). After scouring Craydocs pages, I see that the PXF* functions do not seem to contain this information. Wirawan
Wirawan Purwanto
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