time (entries id_(ZZ^1000);)
time (table(1000,1000,(i,j) -> if i===j then 1 else 0);)
end

is rawIdentity too slow for some reason??

i5 : time (entries id_(ZZ^1000);)
     -- used 2.24047 seconds

i6 : time (table(1000,1000,(i,j) -> if i===j then 1 else 0);)
     -- used 0.456582 seconds
