AMD CPU shoot-out: Phenom X3 and X4
It was time for the Phenom X4 9850, and we weren’t surprised to see that performance was a distinct improvement on the X3 8750 in every respect with the exception of pure graphics tests that only stress the graphics card. The X4 draws 40W more than the X3 which makes it fairly easy to deduce how much power each core in a Phenom requires. The quad-core overclocked slightly better than the tri-core but neither was impressive in that department.
The thing that caused us some surprise, however, is the similarity in price. You only pay £10 more for the X4 so why on Earth would you choose the X3?
Finally, we come to the Phenom X4 9850, which only runs 100MHz faster than the X4 9750 - 2.5GHz - but there are a couple of other changes. The X4 9750 has a TDP of 95W and HyperTransport speed of 1.8GHz while the X4 9850 has a TDP of 125W and a HyperTransport speed of 2GHz which rather suggests that the X4 9850 is buzzing along at the limits of the B3 architecture.
We had heard great things of the X4 9850, with at least one reviewer claiming a clock speed of more than 3GHz. However, we had nothing like that degree of success. With the 200MHz clock raised to 225MHz we immediately suffered a blue screen after Windows had loaded, and that was with a clock speed just over 2.8GHz.
The system was pretty much OK with a clock speed of 220MHz (2.75GHz CPU speed) although 3DMark Vantage refused to run however the X4 9850 required more cooling than the other Phenoms. Indeed we had to remove the add-in fan controller from the CPU cooler to get the fan speed high enough to cool the CPU properly.
That’s all well and good but just take a look at our test results for Core 2 Quad Q6600. On its stock speed of 2.4GHz it wiped the floor with Phenom and when we overclocked it to 3.0GHz it made the AMD silicon look rather limp.
The B3 stepping of Phenom is a distinct improvement over the original B2 but that’s not saying much. Intel has cut the price of Core 2 to such an extent that there is no compelling reason to buy a Phenom beyond the fact that you might not like Intel very much. Fair enough, we'd say, but for everyone else, Intel has grabbed the initiative. Over to you, AMD.