Announcements, 3rd February 2015

KSL Presents the XSEDE HPC Monthly Workshop on OpenACC This Friday

Registration deadline Tomorrow. For registration and further information click here.

Invitation to attend the second KAUST-NVIDIA workshop on "Accelerating Scientific Applications using GPUs" on February 17th, 2015

The Supercomputing Laboratory is pleased to announce the second KAUST-NVIDIA one-day workshop about accelerating scientific applications using GPUs on February 17th.

The registration is free but required using this link.

The event will be followed up by a two day GPU hack-a-thon in which selected teams of developers will be guided by OpenACC and CUDA mentors from NVIDIA and KAUST to port and accelerate their domain science application to GPU accelerators. Space will be limited to 3-4 teams. More details will be communicated to you soon.

Please check the workshop webpage for more details and contact us at training@hpc.kaust.edu.sa if you need further information.

Tip of the Week: Timing your code

To time portions of your code, here are some solutions.

Fortran90:

SYSTEM_CLOCK is standard Fortran90, very efficient, since it is a language intrinsic.

integer :: counti, countf, count_rate
real    :: dt
call system_clock(counti,count_rate)
... work ....
call system_clock(countf)
dt=REAL(countf-counti)/REAL(count_rate)
MPI (both Fortran and C):`

MPI_WTIME is an MPI function, returning the elapsed time on the calling processor.

double precision :: t1,t2,dt
...
t1 = MPI_WTIME()
... work ...
t2 = MPI_WTIME()
dt = t2-t1

C (UNIX):

If you need timing in C and you are not using MPI, you must avoid the typical routines time, times, clock, because all of them return the user time, not the real one. To get the real-time use gettimeofday():

#include <stddef.h>
#include <sys/time.h>
...
double t1,t2,dt;
struct timeval start,end;
int rtn;

rtn=gettimeofday(&start, NULL);
... work ...
rtn=gettimeofday(&end, NULL);
t1=(double)start.tv_sec+(1.e-6)*start.tv_usec;
t2=(double)end.tv_sec+(1.e-6)*end.tv_usec;
dt=t2-t1;

Shaheen becomes Shaheen1

In readiness for the introduction of our new Cray XC40 supercomputer, shaheen.hpc.kaust.edu.sa has been renamed to shaheen1.hpc.kaust.edu.sa with effect from 1st January.

KAUST_HPC on Twitter

Follow all the latest news on HPC within the Supercomputing Lab and at KAUST, on Twitter @KAUST_HPC.