Test: Six X3 & X4 Phenom B3s in detail (page 1: Introduction)

While the Phenom initially received a rather lukewarm reception, new B3 stepping combined with a tri-core versions and more aggressive pricing is supposed to give it a second wind. How do they fare in tests?

What has changed

The benefits of B3 stepping are triple. On the one hand, it enables correcting the TLB bug, an erratum found in early December which affects B2 revision Phenom and Opteron processors. This bug could cause the machine to crash in cases when the TLB was in heavy use. (TLB = Translation Look-aside Buffer, a part of the CPU which accelerates translations between virtual memory and physical addresses). Amongst those applications which can give the TLB trouble AMD mentions virtualization.

The bug, which doesn’t really seem to affect more « classic » use, significantly damaged the Phenom’s reputation because even if it was possible to go around it, the impact on performances was great. Depending on the situation, we obtained 95 to 58% of the CPU’s initial performances.
Another important point is that overclocking is notably easier with the Phenom B3 revision. With the first B2 Phenoms we were happy to attain 2.5 and 2.65 GHz while the Phenom B3 surpasses these frequencies obtaining 3 GHz in some cases. Finally, and even if this is minimal, performances at equivalent frequencies slightly increase 1 to 2%.

In terms of prices, AMD also made some efforts. For example, the Phenom 9500 was launched at $251. Today, we will have to plan on spending $195 for its “B3” equivalent, the Phenom 9550. Actually, the entire Phenom line has had its prices adjusted and the highest performance version, the 9850, is at $235.

Otherwise, access to other Phenoms is cheaper with the arrival of tri-core versions and for example, an 8450 (2.1 GHz) is announced at $145. For comparison, this is situated between the price of an E7200 and E8200.

One last change is that compatibility with AM2 motherboards has been improved. While it was disappointing that our AM2 test mobo, the ASUSTeK M2N32 SLI, didn’t function with Phenoms in our last test, it is now possible! The latest bios updates even add Phenom X3 support.

For more information on the compatibility of your motherboard, you can go directly to the « CPU Support » page of the various manufacturers: ASUSTeK, Gigabyte or MSI. Note that AMD offers the same service.