"keyword keyword2" and keyword1 keyword2

which keyphrase search expend more system resources on Google's servers

[hotice_2002]

I checked two keyphrase with "keyword1 keyword2" (has quotation marks) and keyword1 keyword2(no quotaion marks) on Google. Somebody said the "query" with quotaion marks will expend more system resources of Google's server..
But I did some samples on Google and found the resutls is reversed. The keyphrase with quotation marks spend the query time less than keyphrase of no quotation marks.

Is there any one has some experience on that.

[vitaplease]

I find that if you just repeatidly press the search button, the reported response time always changes.