OCC has published a new review on the Sapphire HD 4550 512MB

Well after some time testing the HD 4550, I found its strengths and weaknesses. First, this card is excellent for video use, whether it be for a workstation PC, a casual use PC, or even a home theater PC. Since it is a low profile card with the bracket included for smaller cases, you will not have any problems getting this card to fit. Being actively cooled will keep the operating temperatures down when inside a small case such as a cramped HTPC case. The Sapphire HD 4550 however should not be taken lightly because of its size. While it was last in all of the video benchmarks, some of the tests were actually playable at the settings tested at. Lighten up on the settings between low and medium and you should be able to pull off reasonable frame rates for some casual gaming. Don't expect to crush any records though. With only 80 stream processors and a 64-bit memory BUS, you are limited on how fast you can perform in games in benchmarks. Trying to overclock this card was like hitting a brick wall, literally. I could not get past the limits of the Catalyst Control Center, no matter what overclocking tool I used. It would just lock up and I had to reboot.

Sapphire HD 4550 512MB Review