Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.python > #59041

Re: Code with random module faster on the vm than the vm host...

Show all headers | View raw

On 11/11/2013 01:15, Ned Batchelder wrote:
> On Friday, November 8, 2013 12:48:04 PM UTC-5, Pascal Bit wrote:
>> Here's the code:
>>
>> from random import random
>> from time import clock
>>
>> s = clock()
>>
>> for i in (1, 2, 3, 6, 8):
>>       M = 0
>>       N = 10**i
>>
>>       for n in xrange(N):
>>           r = random()
>>           if 0.5 < r < 0.6:
>>               M += 1
>>
>>       k = (N, float(M)/N)
>>
>> print (clock()-s)
>>
>> Running on win7 python 2.7 32 bit it uses around 30 seconds avg.
>> Running on xubuntu, 32 bit, on vmware on windows 7: 20 seconds!
>> The code runs faster on vm, than the computer itself...
>> The python version in this case is 1.5 times faster...
>> I don't understand.
>>
>> What causes this?
>
> The docs for time.clock() make clear that the meaning on Windows and Unix are different:
>
> "On Unix, return the current processor time as a floating point number expressed in seconds."
>
> "On Windows, this function returns wall-clock seconds elapsed since the first call to this function..."
>
> Try the experiment again with time.time() instead.
>
> --Ned.
>

http://www.python.org/dev/peps/pep-0418/ for some related reading about 
Python time functions.

-- 
Python is the second best programming language in the world.
But the best has yet to be invented.  Christian Tismer

Mark Lawrence

Back to comp.lang.python | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

Code with random module faster on the vm than the vm host... Pascal Bit <pascalbit@hotmail.com> - 2013-11-08 18:48 +0100
  Re: Code with random module faster on the vm than the vm host... alex23 <wuwei23@gmail.com> - 2013-11-11 10:49 +1000
    Re: Code with random module faster on the vm than the vm host... Robert Kern <robert.kern@gmail.com> - 2013-11-11 01:19 +0000
      Re: Code with random module faster on the vm than the vm host... alex23 <wuwei23@gmail.com> - 2013-11-11 12:16 +1000
  Re: Code with random module faster on the vm than the vm host... Ned Batchelder <ned@nedbatchelder.com> - 2013-11-10 17:15 -0800
    Re: Code with random module faster on the vm than the vm host... Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-11-11 01:31 +0000

csiph-web