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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.

Chris Angelini is an Editor Emeritus at Tom's Hardware US. He edits hardware reviews and covers high-profile CPU and GPU launches.
  • kelfen
    Cheering the underdog in hopes for better compitition to benifit the consumer!
  • groo
    I sure don't see the point of spending cash on DDR3 unless you are also spending cash on i7. I woudn't mind a CPU that can handle DDR3 in the future, but there sure isn't a reason toupgrade to it at today's memory prices.
  • Aatish
    nice review... but....
    strangely AMD is performing better than core i7 920!
    what did I miss? in previous benchmark done by you guys showed AMD performing quite less than what I see in this benchmark! can anyone clear my confusion? please!:)
  • Commlock
    Very good test indeed that shows, IMHO, to go with an overclocked Core i7 if DDR3 is to be preferred. Otherwise, sticking with DDR2 RAM, an AM2+ MoBo and A Phenom II 940-like CPU seems the best optimized system. However, concerns can be put forward on the continuity of the system in couple of years' time, where simply upgrading without major component changes can be discussed.
  • sohei
    an AM2 mobo is compatible with AM3?
  • I understand the fact that you guys compare cpu's in the same price region plus whats available to you and the socket upgrade and all that. But i would really like to see how the AMD 940 Black Edition compare to Intel Corei7 EE 965. And maybe include the corei7 940 to. An all out performance battle with just the benchmark figures that counts
  • waffle911
    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.
    Looks to me like every increment of 10 in the designation yields a 200MHz clock increment, and 5 being 100MHz. But then either the 940 should actually be the 930. Then again, Volvo's recent product nomenclature doesn't add up, either. the V50 is the wagon variant of the S40, and the V70 was the wagon variant of the S60, but is now of the new S80. But they can't change it to V90 because then the Cross-Country variant of the V70 would have to be called he XC90 instead of XC70—but they already have an XC90 SUV. Digging themselves into a hole of consumer confusion, AMD and Volvo both.

    But why is AMD shafting early adopters by shutting out AM2+ PhenomII from the AM3 platform without even offering an AM3 920/940?
  • Well, can't agree with socket chart.
    Let's see (long run)
    AMD&Intel: Socket 7 (intel up to some 266MHz?, AMD up to 550MHz)
    Intel Slot 1 - with FCPGA adapters up to some 1200MHz?
    AMD SlotA - with socketA adapters up to some 1600MHz?
    PPGA s370 ~ 600MHz?
    FCPGA (coppermine) 1100MHz
    FCPGA2 (tualatin) 1500MHz?
    Guess what...PPGA/FCPGA/FCPGA2 were the same socket (s370).
    Now...SocketA ranged from 800MHz Durons to 2GHz AthlonXP 3200+
    P4 start was with socket 423, but intel soon abandoned it for 478, however there were some adapters for some CPUs which allowed s478 CPUs to work on s423 mobos.
    AMD with A64 introduced single channel DDR platform on s754. Later in 939 there was enhancement with dual channel and dual core. But then DDR2 appeared with quite low prices - so they moved to AM2.
    Intel brought LGA775, but most chipsets for Prescott couldn't handle Core 2, later C2D FSB800MHz chipsets couldn't handle FSB1066 and 1333MHz C2D/C2Q cpus. And now we get LGA1366, 1156 and some more for the same familly. Well, I guess intel is more disruptive than AMD. I can put PhenomII 810 AM3 to my AM2 mobo on M1695+NF3, some NF3 ASRock users can do that too. AM2/2+/3 is on the best way to be worthy SocketA successor.
  • raden_muaz
    I've been waiting for so long for this phenom ii to come.
    At last, phenom beats i7 in some kind of way.

    Anyway, I never bought Intel for years because:
  • sohei
    there are 5 sokets technically but 2 physically
    my question is : somebody try a am2/am2+ with a am3 cpu?