Michael Chuah / Mbed 2 deprecated Benchmark

Benchmarking test code for various operations

Dependencies:   mbed

Fork of benchmark by Igor Martinovski

Benchmarking the performance of various mbed boards that I have

Using the excellent code by Igor, I have benchmarked the performance of the following platforms:

The data can be found in this link: https://docs.google.com/spreadsheets/d/1d5BcNvC341xvktRJ6DC3wdlI6wuv0FjCvCqHAnfINmQ/pubhtml

For the hyperbolic tan (tanh) function, I made a graph showing how the clock speed of various ARM Cortex-M4 boards with FPU affects the computation time in microseconds. Computation Time - tanh

Files at this revision

API Documentation at this revision

Revision 3:ec2e20a9bd03, committed 2017-02-28

Comitter:
mcx
Date:
Tue Feb 28 20:54:35 2017 +0000
Parent:
2:fc68d524dd7d
Commit message:
Now prints out clock speed in MHz

Changed in this revision

main.cpp Show annotated file Show diff for this revision Revisions of this file
mbed.bld Show annotated file Show diff for this revision Revisions of this file 
--- a/main.cpp	Thu Nov 19 21:41:58 2015 +0000
+++ b/main.cpp	Tue Feb 28 20:54:35 2017 +0000
@@ -13,17 +13,25 @@
 */
 
 #define ITERATIONS 1000000    // Number of calculations.
-#define CLOCK 48              // Clock freqency in MHz
+#define CLOCK 64              // Clock freqency in MHz
 Timer timer;                       // Timer..
 
 Serial pc(USBTX, USBRX);
 float number_of_cycles, single_operation_time;
-volatile int a, b, c;              // Int operands and result. Must be volatile!
-//volatile float a, b, c;            // Float operands and result. Must be volatile!
+//volatile int a, b, c;              // Int operands and result. Must be volatile!
+volatile float a, b, c;            // Float operands and result. Must be volatile!
 //volatile double a, b, c;            // Float operands and result. Must be volatile!
 
 int main() {
 
+    // Apparently I'm not getting full speed!? 
+    // https://developer.mbed.org/forum/mbed/topic/229/?page=1
+    // https://developer.mbed.org/questions/55557/CPU-clock-of-upto-100MHz/  
+    printf("SystemCoreClock = %d MHz\r\n", SystemCoreClock/1000000);
+    // Need external crystal to make it run faster?
+    // https://developer.mbed.org/users/dreschpe/code/ST_401_84MHZ/
+    // https://developer.mbed.org/users/oliverb/notebook/crystal-oscillator-notes/
+
     unsigned int i, for_time, total_time, operation_time;
     a=2.3;
     b=5.33;
@@ -44,14 +52,15 @@
     this for loop. */
     for (i=0; i<ITERATIONS; i++){
         
-        a = b;
+//        a = b;
 //        c = a+b;
 //        c = a*b;
 //        c = a/b;
 //        a = sqrt(b);
 //        a = log(b);
 //        a = tanh(b);
-
+//        a = (10*pow(b,3) + 105*b)/(pow(b,4) + 45*pow(b,2) + 105);
+        a = (10*b*b*b + 105*b)/(b*b*b*b + 45* + 105);
     }
     
     total_time=timer.read_us();

--- a/mbed.bld	Thu Nov 19 21:41:58 2015 +0000
+++ b/mbed.bld	Tue Feb 28 20:54:35 2017 +0000
@@ -1,1 +1,1 @@
-http://mbed.org/users/mbed_official/code/mbed/builds/9296ab0bfc11
\ No newline at end of file
+http://mbed.org/users/mbed_official/code/mbed/builds/d75b3fe1f5cb
\ No newline at end of file