Although its clock speed of 2.83 GHz is 6% lower than its big brother's 3 GHz, we measured its performance to be 2.4% behind the more powerful model.
Compare the Intel Core 2 Quad Q9550 with the AMD Phenom X4 9750 and other CPUs in our
It's a minimal difference that was only noticeable in certain tests, such as encoding videos.
When it came to encoding our test clip as a DivX file, the Q9550 took 4 minutes 40 seconds, while the Q9650 was just marginally quicker at 4 minutes 23 seconds.
Up against a dual-core processor, though, the discrepancy is a lot more noticeable: the 2.83 GHz E8300 takes 6 minutes 32 seconds to complete the same task.
If you're not a regular user of demanding applications that are optimized for quad-core applications like this one, a dual-core processor with a higher clock speed will be a better bet.
Unfortunately, the weak spot of these powerful quad-core processors is the amount of energy they use.
While the Q9550 was idling, our test PC used 165 W, but 238 W while the CPU was working at 100%;
On a dual-core model like the E8300, these figures are 165 W and 215 W respectively.