Differences

This shows you the differences between two versions of the page.

--- public:matlab_tips [2016/04/04 14:50] – old revision restored (2016/04/02 07:41) fangfufu
+++ public:matlab_tips [2018/02/04 23:51] – fangfufu
@@ Line 12: / Line 12: @@
 </code>
-===== Highly unscientific benchmark of prod() =====
+===== GPU / Host Performance =====
-==== Sparse vs Dense ====
+These results were obtained using [[https://uk.mathworks.com/matlabcentral/fileexchange/34080-gpubench|GPUBench]].
-<code matlab>
+^	^Results for data-type 'double' (In GFLOPS) ^^^Results for data-type 'single'(In GFLOPS)^^^
->> a = rand(1000);
+^Device                       ^MTimes	^Backslash^FFT          ^MTimes  ^Backslash ^FFT   |
->> b = eye(1000);
+^TITAN Xp	                        |422.47	|371.37	  |207.24	|11607.69|1426.76   |763.56|
->> c = sparse(a);
+^GeForce GTX 1080	                |280.84	|223.05	  |137.66	|7707.01 |399.37    |424.60|
->> d = sparse(b);
+^Core i7-4900MQ (Single Thread)	        |123.00	|86.57	  |8.47	        |272.00	 |180.32    |14.31 |
->> tic; for i = 1:10000; prod(a); end; toc
+^GeForce GT 730M	                |27.43	|25.43	  |10.54	|346.57	 |214.98    |27.09 |
-Elapsed time is 7.212577 seconds.
->> tic; for i = 1:10000; prod(b); end; toc
-Elapsed time is 3.566560 seconds.
->> tic; for i = 1:10000; prod(c); end; toc
-Elapsed time is 27.455137 seconds.
->> tic; for i = 1:10000; prod(d); end; toc
-Elapsed time is 0.030041 seconds.
->> tic; for i = 1:10000; prod(a); end; toc
-Elapsed time is 7.250969 seconds.
->> tic; for i = 1:10000; prod(b); end; toc
-Elapsed time is 3.645549 seconds.
->> tic; for i = 1:10000; prod(c); end; toc
-Elapsed time is 27.538796 seconds.
->> tic; for i = 1:10000; prod(d); end; toc
-Elapsed time is 0.029214 seconds.
->>
->> n = 100000;
->> a = rand(n,1);
->> b = 1;
->> tic; for i = 1:n; prod(a); end; toc;
-Elapsed time is 4.849304 seconds.
->> tic; for i = 1:n; b = b * prod(a(i)); end; toc
-Elapsed time is 0.004573 seconds.
->>
-</code>
-==== Prod vs repeated multiplication ====
-=== Script ===
-<code matlab>
-clear;
-n = 10000;
-a = rand(n,1) * exp(1);
-b = 1;
-tic;
-for i = 1:n;
-    c = prod(a);
-end;
-toc;
-tic;
-for j = 1:n
-    for i = 1:n;
-        b = b * a(i);
-    end;
-end
-toc;
-</code>
-=== Results ===
-<code matlab>
->> test
-Elapsed time is 0.168450 seconds.
-Elapsed time is 1.003991 seconds.
-</code>
-Note that with repeated multiplication your numerical accuracy will suffer too!