If I'm understanding you correctly you want to replace the HDD with a larger capacity drive. In that case, for the most part, it won't improve the performance dramatically. A solid state drive would be the biggest improvement in terms of drive speed. The overall storage size won't really speed up the machine it will just give you more room for programs and storage.
Oliver,
If I'm understanding you correctly you want to replace the HDD with a larger capacity drive. In that case, for the most part, it won't improve the performance dramatically. A solid state drive would be the biggest improvement in terms of drive speed. The overall storage size won't really speed up the machine it will just give you more room for programs and storage.
Hope that helps,
-b