I want to duel boot windows and Ubuntu, however i don't want anything on windows to be able to access my Linux partition. Is there anyway to do this without encryption? As i don't want to slowdown read/write times on my Linux system.
You have 2 options, to stop deletion.
Separate hard-disks, and hardware switches.
If you want to do it with the same hard-disk, then you will need some virtualisation software to run under MS-Windows.
There is no other way, as MS-Windows is an operating system, it can do what ever it wants with the hardware.
To stop read, then you can use encryption (your solution).