Posted 25 June 2010 - 08:33 AM
DMIPS is based on the time taken to execute a particular benchmark, something which might be considered representative of a real workload, namely Dhrystone. The DMIPS figure for a given machine is the relative speed a VAX 11/780 (a particular "1 MIPS" machine) would have to run at to complete the benchmark in the same amount of time as the machine being measured. For example, if a 100MHz CPU completes the benchmark 200 times faster than the VAX 11/780 does, then it would be considered a 200 DMIPS machine. For CPUs that can be run at various frequencies, then you'll often see this value reported divided through by MHz, e.g. 2 DMIPS/MHz in this example.
So, the quick answer is that (unlike MIPS) DMIPS can't be calculated, it can only be measured.
There are further details, and a link to the Dhrystone source code here: http://en.wikipedia.org/wiki/Dhrystone
This post has been edited by sim: 25 June 2010 - 08:35 AM
Posted 26 June 2010 - 09:19 AM