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Socket AM3: AMD's Phenom II Gets DDR3

A Slew Of New CPUs

In concert with the platform launch, AMD is releasing six AM3 processors—five will be available in the channel and a sixth will only go out to OEMs.

New Socket AM3 Processors
ModelFrequencyL3 CacheVoltageModel #’sSocket
Phenom II X4 9102.6 GHz6 MB0.875-1.425VTray: HDX910WFK4DGIAM3, AM2+, AM2
Phenom II X4 8102.6 GHz4 MB0.875-1.425VTray: HDX810WFK4FGI; PIB: HDX810WFGIBOXAM3, AM2+, AM2
Phenom II X4 8052.5 GHz4 MB0.875-1.425VTray: HDX805WFK4FGIAM3, AM2+, AM2
Phenom II X3 720 BE2.8 GHz6 MB0.850-1.425VTray: HDZ720WFK3DGI; PIB: HDZ720WFGIBOXAM3, AM2+, AM2
Phenom II X3 7102.6 GHz6 MB0.875-1.425VTray: HDX710WFK3DGI; PIB: HDX710WFGIBOXAM3, AM2+, AM2
Phenom II X4 940 BE3.0 GHz6 MB0.875-1.5VTray: HDZ940XCJ4DGI; PIB: HDZ940XCGIBOXAM2+, AM2
Phenom II X4 9202.8 GHz6 MB0.875-1.5VTray: HDX920XCJ4DGI; PIB: HDX920XCGIBOXAM2+, AM2

Hopefully you’re good about keeping names straight, because AMD is making it even more difficult to decipher its model numbers with yet another variable factored in--L3 cache size. Let’s break down the name of its Phenom II X3 720 BE as an example.

Phenom II: this one is easy enough. We’re hoping you know the difference between Athlon 64, Phenom, and Phenom II already. If not, check out Bert’s launch piece, AMD Phenom II X4: 45 nm Benchmarked.

X3: The number after the X denotes how many cores are active. The X3s employ the same die as the quad-core X4 processors, but only three cores are usable.

720: Here’s where things get more complicated. The first digit is a general class designator. AMD’s 900-series chips are full-fledged Phenom IIs, with four cores active and 6 MB of L3 cache. The 800-series chips also sport quad-core configurations, but they come with less L3 cache—4 MB instead of 6 MB. The 700s start with the highest-end X3s, also with 6 MB of cache. We presume this leaves room for a 600-series at some point wielding three cores and 4 MB of L3, but that’s just conjecture at this point.

The second two digits are indicative of clock speed. Unfortunately, there doesn’t seem to be a formula to predict where a given number will land you. The 940 runs at 3 GHz. The 920 and 720 both cruise at 2.8 GHz. But the 910, 810, and 710 all run at 2.6 GHz. There goes the idea that each increment of 10 corresponds to 100 MHz. The 805 chugs along at 2.5 GHz. You get the general concept.

Finally, there’s the Black Edition modifier, affixed to the X4 940 and X3 720, which tell you that the processor’s multiplier is unlocked, enabling more flexible overclocking.

We see this naming convention, which is somewhat universal across the new Phenom II lineup, as likely to leave room for error on the buyer’s part. There’s no variable distinguishing the AM2/AM2+-only Phenom II X4 940/920 from the new AM3 components. Further, it’s interesting that an enthusiast looking to step-up to AM3 with DDR3 would need to buy a CPU in the middle of AMD’s Phenom II lineup, since the flagship is limited to an older socket interface.

We discussed the omission of a higher-end AM3 part with AMD, and the consensus was that AMD isn't expecting many enthusiasts to buy AM3 motherboards and processors just yet. Rather, it's eying the upgrade market, full of folks looking to drop these new chips in existing AM2/AM2+ boards. Hence the more value-oriented offerings at launch. Purportedly, a higher-end AM3 part will follow shortly.


We don’t have prices on the entire line of AM3-ready processors, but AMD has indicated that the Phenom II X4 810 will bear a $175 price tag and the Phenom II X3 720 Black Edition will cost $145.

Conversations with motherboard vendors indicate that AM3 boards will be priced similarly to AM2/AM2+ predecessors. Asus’ M4A79 Deluxe—a Socket AM2+ board based on AMD’s 790GX/SB750 combination—currently sells for right around $200. The M4A79T Deluxe—the Socket AM3 replacement centering on the same platform—will also sell for $200, according to Asus.

Last-generation's Asus AM2+ board next to the new AM3 platform

Also worth noting is that AMD’s Phenom II X4 940 Black Edition and 920 processors have already dropped in price since the launch in early January. The 3 GHz 940 is now set at $225, while the 2.8 GHz 920 costs $195 in quantities of 1,000. The implications there are significant given the initially very-close comparison between AMD’s fastest Phenom II and Intel’s entry-level Core i7.