Like the rest of AMD's Phenom X4 processor range, this 9550 is an entry-level quad-core CPU.

It comes at a very attractive price, and most of its competition comes from dual-core processors rather than other chips with four cores.

Indeed, Intel's Core 2 Quad Q8200 outperformed it by so much that we think its most direct competition comes from the Core 2 Duo E7300.


Our test results provided a very definite conclusion: the X4 9550 is only a good investment if you plan to use applications that are optimized to make the best of its quad-core architecture.

If you don't plan to use software that makes much use of the four cores, you'll be better off with the two cores in a chip like Intel's E7300.

To give a concrete example, we tried our video encoding test which involves rendering a H.264 video.

The X4 9550 took 2 minutes 19 seconds, as opposed to the 2 minutes 52 seconds taken by its rival.

In this instance, the advantage of doubling the number of cores is clear, even if it isn't as pronounced as it ought to be.

But when we tried ripping an audio CD to MP3 in iTunes, which doesn't make use of the extra cores, the X4 9550 really lagged behind, and its average score of 3 minutes 12 seconds was more than twice as slow as the E7300's 1 minute 26 seconds.

Finally, if you plan on gaming, then these X4 processors are definitely best-avoided.

In our tests on World in Conflict, the X4 9550 only managed a framerate of 25 fps, while the E7300 from Intel easily reached 34 fps.

To conclude with a look at their energy consumption, it's fair to say that this really isn't the X4 series' strong point.

When it was idling, our test PC used 195 W, climbing to 292 W when CPU load was at 100%.

As a sample comparison, the Core 2 Quad Q8200 uses 161 W and 222 W respectively in the same conditions, while the E7300, a dual core processor, uses 155 W and 196 W respectively.