ARCHIVED: Make the best use of your system's memory in Mathematica

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In Mathematica, you can use ClearAll to recover memory associated with calculations you no longer need. For this to work, you must also remove your output history with Unprotect and Clear[Out].

Mathematica will use some amount of memory to start up:

In[1]:= MemoryInUse[] Out[1]= 812448

If you create a large matrix (for example, t) but suppress the output, and then check the memory again, you'll see the memory used increases:

In[2]:= t = Table[Random[], {1000}, {1000}]; In[3]:= MemoryInUse[] Out[3]= 20843256

If you clear the variable (for example, t) from memory, the memory used increases slightly again:

In[4]:= Clear[t] In[5]:= MemoryInUse[] Out[5]= 20844712

However, if you also clear the output from memory, you reduce the memory used to nearly the minimal amount:

In[6]:= Unprotect[Out] Out[6]= {Out} In[7]:= Clear[Out] In[8]:= Protect[Out] Out[8]= {Out} In[9]:= MemoryInUse[] Out[9]= 827120

If you have questions about using statistical and mathematical software at Indiana University, contact the UITS Research Applications and Deep Learning team.