SFO Controller described near loss of departure separation when first aircraft slowed and second increased speed; reporter suggested company operational speed characteristics be standardized.

Narrative

Departed Aircraft Y from Runway 01R on SFO8 departure; departed Aircraft X from Runway 01R when Aircraft X was approximately 1/4 mile from the departure end of Runway 01R. On shipping Aircraft X to departure control; noticed at least 3.25 miles of separation and Aircraft X less than Aircraft Y. Performed other control duties; happened to look at radar and observe Aircraft X barely 3 miles from Aircraft Y and at same speed. In the last few years; with the increase in regional jets and airbus model aircraft; there is a large; and unpredictable; amount of speed variations on departing aircraft. I believe pilots and companies operating these aircraft all have different operating rules regarding climb out speeds. This is resulting in slower jet powered aircraft departing in front of faster jet powered aircraft. There needs to be recommendations and procedures to standardize aircraft performance in terms of climb out speeds. If a company wants to operate at fuel conserving climb profiles they should have to file an advisory or advise controllers that they will be operating at slower speeds than is standard for jet powered aircraft.