AMD Athlon II X2 / Phenom II X2 And Low-Power CPU Bonanza

Dual-Core Alphabet Soup: Athlon, Phenom—Both X2s

Perhaps I was a little whiney when AMD launched its Phenom II X4 810 and Phenom II X3 720 Black Edition, claiming that the naming was getting a little ridiculous, if not difficult to keep straight. But now that we have yet another product family to add to the stack, it only gets more convoluted. Take the following slide from AMD’s press briefing:

Along this performance continuum we have Athlon X2s (with and without L3 cache), Phenom X3s, Athlon II X2s, Phenom II X2s, Phenom II X3s, and Phenom II X4s. Missing are the original Phenom X4s as well as the Athlon II X3 and Athlon II X4 expected in July.

I’m not about to defend Intel’s lineup. Core 2 Duo, Core 2 Quad, and Core i7 are easy enough to keep straight, but it’s quite a bit harder to remember what the Q9000-, Q8000-, E8000-, E7000-, E6000-, E5000-, and Celeron E1000-, and 400-series models really include. And as you travel down the lineup, you start giving up virtualization support, SSE 4.1, vPro, etc. The whole concept of whittling off features in the name of product differentiation becomes problematic, especially in the face of upcoming Windows 7’s “XP Mode,” which uses virtualization to facilitate application compatibility with older software. When you consider that this is a capability aimed at businesses, and given that many businesses celebrate the stable image of Intel’s platforms, we already see it becoming easy fodder for AMD’s marketing cannon. Whoever it was at Intel who thought up the idea of axing virtualization as a good differentiator must have missed a meeting with Microsoft.

AMD's Athlon II X2: Regor

The point is that AMD’s Athlon II X2 gives you yet another architecture to keep straight. This one sports the 64 KB of L1 data/instruction cache per core common to all of the Phenoms and Athlon X2s and 1 MB of L2 cache per core—there is no L3. Internally referred to as the Regor core, the Athlon II X2 is manufactured at 45 nm, resulting in a 234 million transistor die measuring a tidy 117.5 square millimeters. It’s compelling, then, that the processor is rated at a 65 W TDP. Also notable is that this is AMD’s first processor with the C1E enhanced halt state enabled in hardware. Past processors have required BIOS updates in order to add support; this is no longer the case. Sigh. At least performance and socket/memory compatibility are the only ways in which all of these processor families differ.

AMD is only announcing one model at launch: the Athlon II X2 250 running at 3 GHz. With a northbridge clocked at 2 GHz and a memory controller capable of supporting DDR2-1066/DDR3-1333, this native dual-core processor looks like it could be a strong mainstream contender. Given an $87 price point, we expect this one to go up against Intel’s Pentium E6300.

Swipe to scroll horizontally
Header Cell - Column 0 AMD Athlon II X2 250AMD Phenom II X2 550 BEIntel Pentium E6300
CoreRegor (dual-core)Callisto (dual-core)Wolfdale-2M (dual-core)
Manufacturing Process45 nm45 nm45 nm
Frequency3.0 GHz3.1 GHz2.8 GHz
L1 Cache (I / D)64 KB / 64 KB64 KB / 64 KB32 KB / 32 KB
L2 Cache1 MB/Core512 KB/Core2 MB Shared
L3 CacheNone6 MB SharedNone
TDP (W)65 W80 W65 W
QPI/HT/FSB4,000 MT/s4,000 MT/s1,066 MT/s

The Athlon II X2 looks like a darling—right up until you see the other dual-core chip AMD is unveiling: its Phenom II X2. Based on what is being referred to as the Callisto design, you can also think of this CPU as Deneb minus two execution cores; everything else remains intact.

Phenom II X2: Callisto (Deneb with two cores turned off)

Again, we have 64 KB of L1 data/instruction cache per core, and like AMD’s other Phenom IIs, this one sports 512 KB of L2 cache per core and a 6 MB shared L3. There's a 2 GHz memory controller with DDR2-1066/DDR3-1333 support, Socket AM3 interface—am I sounding like a broken record yet? Take a Deneb. Lop off two cores. Voila, Callisto. Only the cores haven’t been lopped off. They’re still there. More on this in a couple of pages.

The only model in this family that AMD is discussing today is its Phenom II X2 550 Black Edition, which cruises along at 3.1 GHz, costs $102 ($15 bucks more than the Athlon II X2 250), and sports the unlocked multiplier synonymous with AMD's Black Edition modifier. Of course, it’s manufactured on the Globalfoundries 45 nm process and, being based on Deneb, consists of a whopping 758 million transistors in a 258 square millimeter die. Because two of the chip’s cores are turned off, its TDP drops to 80 W.

Chris Angelini
Chris Angelini is an Editor Emeritus at Tom's Hardware US. He edits hardware reviews and covers high-profile CPU and GPU launches.
  • IronRyan21
    Maybe if AMD would actually bring out some kind of nehalem competitor instead of flooding the cheapo market with variations of the same chips all over the place. There was Athlon 64 X2, brisbane and windsor, then there was Kuma, which was a phenom with 2 cores disabled. Now we got these new chips which are phenom 2s with 2 cores disabled. Lets put the money into some R&D and get somewhere. It seems like AMDs lost traction. sad.
  • thedipper
    IronRyan21Maybe if AMD would actually bring out some kind of nehalem competitor instead of flooding the cheapo market with variations of the same chips all over the place. There was Athlon 64 X2, brisbane and windsor, then there was Kuma, which was a phenom with 2 cores disabled. Now we got these new chips which are phenom 2s with 2 cores disabled. Lets put the money into some R&D and get somewhere. It seems like AMDs lost traction. sad.
    The low to mid-price segments are the best selling hardware categories.

    Believe it or not, the $100 bang-for-the-buck graphics cards by far outsell the $500 space heater graphics cards. As with graphics cards, $50-100 CPUs by far outsell the $300-1300 CPUs.

    The market that seems like most of the market - the enthusiasts and gamers - is actually not that much of the market share. Businesses building for performance-per-dollar, low-mid performance factory built home PCs, and people building web or media machines... these together outweigh the enthusiast/gamer market.
  • jj463rd
    Those Phenom II 905e's and 705e's would be kickass if paired with the upcoming 785g motherboards.
    AMD has some new interesting CPU's.
  • @IronRyan: Why not start your own semiconductor company and show AMD how it's done? Can a similar argument not be applied to Intel's "double cheeseburger" quads, and "single patty" dual-cores? If we even get any non-quad i7/i5s, do you know if Intel won't just do the same thing? In the future, instead of coming up with some lame argument, just post this for each article:

    "Hi, my name's IronRyan, and I like Intel. Go team Intel, yay!!!!!"
  • deputc26
    Anyone else see the Athlon X2 and think that if they underclocked and undervolted it they'd finally have a legitimate mobile contender?
    If they can run 4 cores at 2.5ghz and 8mb cache on 65w they should be able to run 2 cores at 2.5 ghz and 2mb cache at less than 32.5w.
  • rdawise
    Interesting article...I'm glad you put this against the E6300. I haven't seen much about this chip. It as if Intel just snuck on onto the market. I wonder how high of an overclock you can get with it....

    Onto the article, it seems as if the Phenom II x2 550 BE would a great chip in a value gaming rig. If you could unclock the extra cores and get it stable, you'd be one lucky man. Can't wait till see these on the Egg...
  • cangelini
    Quickest Pentium, only one with a 1066 MHz bus, disappointing that it's missing some functionality, though.

    Anyone else reminded of GeForce 2 MX when they see how Intel is positioning its mainstream chips these days? I'm all for differentiating with performance to drive down price (even cutting performance-oriented features, like Hyper-Threading), but don't start shedding the actual capabilities of an architecture to handicap it.
  • I would find the Phenom X2 550 interesting because many of the programs I still run today are singlethreaded.
    These programs benefit more from a higher clockrate than more cores.

    Keeping this in mind, and the fact that an OS doesn't (spectacularly) boot faster with more cores, I think the X2 is a great buy.
    I'm a bit dissapointed at the powerdraw. For a HDTV box you don't necessarily need to buy a Radeon 4850. Perhaps a lower powerdraw (and price) in the 4770 or 4670 will be better.
    To playback full HD (1080p) I suppose a Radeon HD 2900XT would be enough.
    Add office tasks, internetting, some photoshop, and casual gaming on a 22"monitor (1680x1050 pix), and a Radeon 4670 would be enough in most cases.
    If you have a 24" monitor (1920x1200 pix) a Radeon 4770 would do.
    Only when latest gaming is concerned should you go for a Radeon 4870 or a 4890.
  • Gin Fushicho
  • cangelini
    Pro, for an HTPC, you'd be fine with a 4670, more than likely. The challenge will be building a system able to keep that setup cool enough. The Maui box with the 905e was *near-silent* but a discrete card would have wrecked this, and a 4670 is almost too much card to be passively-cooled (a la Ultimate-style) without better airflow in the case.