Context switch timer. Includes some overhead for some system calls. Times are for 100,000 context switches.

CUUG Machines

hp      (hp715)          8.13 secs, 12.19/millisec  82 microsec/switch
sun     (sparc20)       11.00 secs,  9.09/millisec 122 microsec/switch
dec     (axp3300)       13.64 secs,  7.33/millisec 136 microsec/switch
hp      (hp712)         15.25 secs,  6.56/millisec 152 microsec/switch
ibm     (C10)           16.05 secs,  6.23/millisec 161 microsec/switch
cuug486 (linux)         16.29 secs,  6.14/millisec 163 microsec/switch
sun     (sparc2)        23.96 secs,  4.17/millisec 240 microsec/switch
ibm     (320)           68.67 secs,  1.46/millisec 687 microsec/switch

Other Machines

qnx 4.2 (486DX2/66)      6.91 secs, 14.46/millisec  69 microsec/switch
qnx 4.2 (486DX/33)       9.56 secs, 10.46/millisec  96 microsec/switch
linux   (486DX2/50)     13.87 secs,  7.21/millisec 139 microsec/switch
qnx 4.2 (386DX/40)      14.97 secs,  6.68/millisec 150 microsec/switch

* if you run the benchmark on a system different than these, please send me
  the results to be included here.