http://www.gpureview.com/show_cards.php?card1=625&card2=466
The HD 5450 is well below that one in overall performance, although it does beat it in shader operations.
It wasn't designed for gaming, but it has acquired various aspect of the more advanced generations as time has passed, such as the many shader processors that the HD 4n00 and HD 5n00 generations added. It should be able to run an elderly game such as Oblivion, although not as well as the XBox360.
I installed version 11.7 earlier today, so am fully up to date with the software.
I'll be playing it on the 360, for the first 1-2 playthroughs but then will buy the PC version, when more mods are available. So I have plenty of time to upgrade my PC or even get a new one but as I mentioned in a previous post the graphics on my PC version are better than the 360 anyway.