Multi threaded matrix ldivide
7 views (last 30 days)
Show older comments
Tung-Duong
on 17 Aug 2017
Answered: guoliang song
on 28 Jan 2020
Could anyone please confirm? A \ B is multi-threaded for dense matrices but single-threaded for sparse matrices. I watched the Resource Monitor in Windows 10 in both cases and saw only activity on 1 core in the case of sparse matrices (Matlab 2017a). If this is true, is there any way to get multi-threading on sparse \ operation?
0 Comments
Accepted Answer
John D'Errico
on 18 Aug 2017
Backslash works in an automatically multi-threaded form ONLY on dense matrices, and only for systems that are sufficiently large. I recall verifying this fact, although it may change in some future release.
I believe there is currently nothing you can do to force multithreading for a sparse system solve. Even, for example, if you have the parallel processing TB, you still cannot break the problem up.
3 Comments
Joss Knight
on 18 Aug 2017
Edited: Joss Knight
on 18 Aug 2017
For sparse solves on the GPU only a vector RHS is currently supported. This is because that is what the underlying library (cusolver) supports. So B has to be a vector. Also you say A is non-square in one paragraph and then you say it's square in the next. At the moment, only square A is supported.
More Answers (1)
guoliang song
on 28 Jan 2020
I also have this problem and it seems very strange.
a\b (a is about 60k*6k)
On my old PC(i7/4core,matlab2017). It can use all 4 core.
On my new PC(i9/10core,matlab2017). It can only use 1 core.
Same result in matlab2019b.
0 Comments
See Also
Categories
Find more on Loops and Conditional Statements in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!