Phenom II Gets a New Revision: 125W AMD Phenom II X4 965 Black Edition Performance Preview

Introduction

It’s been 2.5 months since we first looked at AMD's flagship 3.4GHz Phenom II X4 965 Black Edition CPU. Back then, we suggested you wait until September to see how the CPU landscape was affected by the arrival of Intel’s Lynnfield Core i5/Core i7 processors.

We knew that thanks to its Nehalem roots, Lynnfield was going to deliver stellar performance, and thanks to leaked Intel price lists, we also knew that Intel was going to be pricing Lynnfield CPUs pretty aggressively, particularly at the low end with the Core i5-750 selling for less than $200 officially.

What we didn’t know was how long it would take for AMD to respond with price cuts of their own, and how aggressively they’d cut their CPU prices. Obviously with the Core i5-750 sitting out there delivering better overall performance and low pricing, AMD’s $245 launch price for the Phenom II X4 965 wasn’t going to work.

AMD took a little longer to reduce prices than we expected though. They didn’t cut prices until October 20th – that’s over a month after Lynnfield’s arrival. They also used the opportunity to axe a number of products, including fan favorites like the Phenom II X3 720 Black Edition and Phenom II X2 550 Black Edition CPUs. These CPUs are highly sought after amongst AMD enthusiasts on a budget, as they’re based on the same Deneb core found in AMD’s 955 and 965 CPUs, only with slower clock speeds and processing cores disabled.

If you took our advice and waited, you saved yourself some money; this is why we initially wanted you to wait (we just didn’t expect it to take as long as it did to get those cuts.) If you’ve still been sitting on the sidelines waiting, we’ve got even better news for you: AMD has just put the finishing touches on a new CPU revision for the Phenom II X4 965 Black Edition. This new revision delivers reduced power consumption – AMD lists a TDP of just 125W versus the original’s 140W – and a number of other improvements.

Improving Phenom II

We’ve always been big fans of new CPU revisions/steppings, as AMD and Intel have used them to introduce a number of goodies in the past. As many OC’ers can tell you, newer steppings can often scale to higher clock speeds than older ones. But that’s not all they can potentially be useful for. Newer CPU steppings can be introduced to fix bugs (errata) in hardware, deliver higher clock speeds, improve yields, or to reduce power consumption.

It turns out that AMD’s latest revision for the Phenom II X4 965 Black Edition incorporates numerous improvements over the original RB-C2 revision, which AMD has used previously for all Deneb Phenom II CPUs, including the old AM2+ parts launched at the beginning of this year.

The new Phenom II X4 965 Black revision is “RB-C3”, or C3 for short.

Here’s the list of improvements introduced with the C3 revision, straight from AMD:

TDP = 125W (down from 140W)

Hardware C1E implemented: Faster switching of power states means virtually no impact to performance by power management when BIOS support is properly implemented

“Heavy” load support for DDR3-1333: With proper BIOS implementation, memory controller will now support up to 4x DDR3 DIMMs at 1333MHz

Notes

As you can see, the new C3 revision incorporates two enhancements beyond lower TDP. We typically disable power saving features like C1E in order to produce optimal CPU performance, then re-enable it when running power consumption. The new C3 chips can switch power states much quicker than older CPUs based on AMD’s C2 revision, reducing the performance hit you can sometimes encounter in some apps when power management features are enabled in BIOS.

The other significant tweak AMD has incorporated into their new C3 revision is support for up to 4 DIMMs at DDR3 1333MHz speeds. Previously AMD was limited to supporting just 2 DIMMs at DDR3-1333.

One other benefit we should mention of the new C3 revision chips is lower operating temps: with lower power consumption, one side benefit is that the chip also generates less heat as a result.

But that’s not all. AMD also says the new C3 revision CPUs should overclock further than C2 processors. Let’s put that one to the test shall we?