netcdf largeFillValue { // format variant: 64bit
dimensions:
x = 39393 ;
y = 17766 ;
variables:
double x(x) ;
double y(y) ;
double z(x, y) ;
z:_FillValue = 9.96920996838687e+036 ;
}
Remember you are creating a layer and it may be subjected to the memory of your system. While you may have a lot of RAM to spare ArcMap is a 32 bit process in the foreground and at 10.1 background it is 64 bit. Can you indicate if the process fails due to memory? While I have never tried to create a NETCdf of that size, I would think that the limitations of a layer file on your system would be the issue.
I've found the problem. Z must be stored in row-major order, ie z(y, x), not z(x, y).
The latter works, but is unusably slow especially with larger data sets (presumably once the size of z exceeds the cache).