Search found 9 matches

by thanasis_giannis
Sat Nov 11, 2017 9:45 am
Forum: User discussion
Topic: dot slower in gpu
Replies: 5
Views: 1577

Re: dot slower in gpu

So I did measured dot in a seperate file and indeed starts to have a good performance for vectors of 50 000 elements..that s why i get bad timings i didn t test my code for 50 000 elements...
by thanasis_giannis
Sat Nov 11, 2017 5:13 am
Forum: User discussion
Topic: dot slower in gpu
Replies: 5
Views: 1577

Re: dot slower in gpu

Actually I timed the specific function (dot) every timed it was called in a certain function and in cpu us way faster from gpu
by thanasis_giannis
Thu Nov 09, 2017 4:56 pm
Forum: User discussion
Topic: dot slower in gpu
Replies: 5
Views: 1577

Re: dot slower in gpu

I am using a i7-3770K CPU @ 3.50GHz with Tesla K40c with linux ubuntu. The vectors are 10000 and I am not timing data transfers. I am using magma_ddot as part of a bigger code and I see that If i use the cpu code is 5 times faster than the gpu code dot is called many times and the cumulative times a...
by thanasis_giannis
Thu Nov 09, 2017 2:58 pm
Forum: User discussion
Topic: dot slower in gpu
Replies: 5
Views: 1577

dot slower in gpu

So I found out that magma_?dot() seems to be a lot slower than the cpu code...Can anyone tell me why this is happening?

Thank you!
by thanasis_giannis
Thu Oct 19, 2017 9:39 am
Forum: User discussion
Topic: Gpu worse than cpu
Replies: 3
Views: 1051

Re: Gpu worse than cpu

Well....maybe I have found something...according to google....functions like axpy are likely to be slower in gpu. Something that has to do with memory. My code is full functions like axpy..so i guess that is...
by thanasis_giannis
Wed Oct 18, 2017 12:32 pm
Forum: User discussion
Topic: Gpu worse than cpu
Replies: 3
Views: 1051

Gpu worse than cpu

Hello,
I have a piece of code that originally is running with mkl. I did put magma instead of mkl commands and the timing was worse. The function that I am timing has no data transfers. I really don t know what might have been wrong. Also, I am new to this :D
by thanasis_giannis
Thu Aug 24, 2017 5:56 pm
Forum: User discussion
Topic: magma_init() takes up to 2 seconds to init
Replies: 4
Views: 2117

Re: magma_init() takes up to 2 seconds to init

thanasis@cuda:/usr/local/magma-2.2.0/testing$ ./testing_dgetrf -n 100 % MAGMA 2.2.0 compiled for CUDA capability >= 3.0, 32-bit magma_int_t, 64-bit pointer. % CUDA runtime 7050, driver 7050. OpenMP threads 1. MKL 11.3.0, MKL threads 1. % device 0: Tesla K40c, 745.0 MHz clock, 11519.6 MiB memory, ca...
by thanasis_giannis
Thu Aug 24, 2017 7:40 am
Forum: User discussion
Topic: magma_init() takes up to 2 seconds to init
Replies: 4
Views: 2117

magma_init() takes up to 2 seconds to init

Is it normal for magma_init() to take up to 2 seconds to init? And if no, what could cause this?

Thank you in advance!