# Prevent Mathematica using previous result [closed]

How can I prevent mathematica from using the previous computation in new one? How do I make the code below to compute same amount of time without memorizing previous computation.

  In[25]:= AbsoluteTiming@Sum[i^3 + 4. i^2, {i, 1000000}]

Out[25]= {2.9587, 2.50002*10^23}

In[26]:= AbsoluteTiming@Sum[i^3 + 4. i^2, {i, 1000000}]

Out[26]= {2.64804, 2.50002*10^23}


## closed as off-topic by Jason B., user9660, dr.blochwave, MarcoB, m_goldbergOct 21 '15 at 15:01

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "This question arises due to a simple mistake such as a trivial syntax error, incorrect capitalization, spelling mistake, or other typographical error and is unlikely to help any future visitors, or else it is easily found in the documentation." – Jason B., Community, dr.blochwave, MarcoB, m_goldberg
If this question can be reworded to fit the rules in the help center, please edit the question.

• Look up ClearSystemCache[]. – J. M. is away Oct 21 '15 at 7:05
• How reproducible is this? I don't find the same thing happening here – Jason B. Oct 21 '15 at 7:09
• I made a mistake, in the first I used 4. in the second 4. So the expressions were not equivalent. Corrected. Seems to be little memorization going on here. Still good to know the ClearSystemCache[] – Al Guy Oct 21 '15 at 7:16