I been playing Skyrim on the pc for a while, runs like a dream, but yeah I got bored of Skyrim and wanted to play Oblivion, but the strange thing I got super low FPS playing Oblivion, and I played Skyrim on pretty decent graphics. Any reason why Oblivion requires more than Skyrim? and is there a way to make Oblivion work better?

My stats are

AMD Phenom™ 8400 Triple-Core Processor 2.10 GHz
Windows 7 home edition(im not really sure)
4 GB Ram
NAVIDA GeForce GTX 550 Ti (1GB if Im not wrong)

You need a faster CPU. Oblivion is even more limited by the CPU than Skyrim.

I have 3.07 GHz and it works seamlessly on highest settings.