On my PC (which is a long way from being a “Supercomputer”) this is what I get on a fresh kernel:
In[1]:=
MemoryInUse[]
MaxMemoryUsed[]
Out[1]= 97675416
Out[2]= 98118248
In[3]:=
F[x_,y_,g_]:=x-(Exp[y]-Exp[-g*y]);
y0=2*ArcSinh[x];
x=10;
g=10^10;
y/.FindRoot[F[x,y,g],{y,y0},WorkingPrecision->50,PrecisionGoal->30,AccuracyGoal->\[Infinity]]
Out[7]= 2.3025850929940456840179914546843642076011014886288
In[8]:=
MemoryInUse[]
MaxMemoryUsed[]
Out[8]= 94880360
Out[9]= 10908680648
Finding the root takes less than 5 seconds