The Phenom Inspired, Core i7-like, Phenom II

Want to hear something funny? When AMD launched the original Phenom, it was a unique looking architecture, something AMD touted as a significant advantage due to its "native" monolithic quad-core design (four cores, one die). I often argued that it wasn't an advantage, simply because the performance numbers didn't back up AMD's claims. AMD never won a real world desktop benchmark because of the monolithic quad-core design.

Intel followed up with Nehalem (Core i7), a microprocessor that had a very Phenom-like cache hierarchy (four cores, private L2 caches, one large shared L3 cache), but with much better performance.

Phenom II builds upon the same architecture as the original Phenom, hardly changed, but improves on a few key limitations. This isn't a new microarchitecture, this is a 45nm shrink of Phenom. In a sense, AMD gave up on improving the original Phenom. Early on after Phenom's release AMD went head in the sand and did whatever was necessary to make the 45nm transition perfect. Deneb, as it was called internally, had to succeed - because AMD as a company wasn't going to survive on the backs of the GPU division forever. It's somewhat ironic that Intel was able to execute a better Phenom-like microarchitecture before AMD.

Processor AMD Phenom II AMD Phenom Intel Core i7 Intel Core 2 Quad Q8xxx/Q9xxx
Manufacturing Process 45nm 65nm 45nm 45nm
L1 Cache 64K + 64K per core 64K + 64K per core 32KB + 32KB per core 32KB + 32KB per core
L2 Cache 512KB per core 512KB per core 256KB per core 2x3MB, 2x4MB or 2x6MB
L3 Cache 6MB 2MB 8MB -
Transistor Count 758M 450M 731M 456M (6MB/8MB L2) or 820M (12MB L2)
Die Size 258 mm2 285 mm2 263 mm2 164 mm2 (6MB/8MB L2) or 214 mm2 (12MB L2)

The above chart details the specifications for the current AMD and Intel quad-core offerings, and here we see a problem. Phenom II and Core i7 are around the same die size and have similar transistor counts, yet Core i7 sells for $284 - $999 while Phenom II sells for $235 - $275. The part that Phenom II actually competes with is the Core 2 Quad Q9400 (and perhaps the Q9550; more on that later), and that's a ~36% smaller die. This is the downside to AMD's pricing strategy; while it's great for consumers it's not particularly great for AMD's profit margins. The other thing to keep in mind is that at 214 mm2 Intel has an entire line of quad-core processors that, in theory, could be moved down the price list if the price wars of 2008 were to continue into 2009.

The move to 45nm was severely needed as you can see by the table above. AMD and Intel seem to agree on the right way to build a quad-core processor today: four cores with individual L2 caches (or one shared L2 per two cores on Intel) behind a large global L3 cache. Intel, however, waited until the 45nm transition was complete to move to that sort of an architecture in order to outfit the chip with a large enough L3 cache. AMD jumped the gun early with Phenom and was forced to limit its L3 cache size to 2MB on 65nm. Finally, with the move to 45nm, Phenom II boasts a 6MB L3.

The transistor counts of Phenom II and Core i7 are surprisingly close, as are the die sizes. The two chips are designed completely differently, but the end result is similarly sized processors. Note that both Phenom II and Core i7 are too big for high volume mainstream markets; the die size would need to be around half of what it is now to address those markets. AMD and Intel will do so by introducing dual (or triple in the case of AMD) core versions at 45nm and then transitioning almost exclusively to quad-core at 32nm.

Phenom II also marks AMD's return to the >$200 CPU market. The two parts launching today are the Phenom II X4 940 and the Phenom II X4 920, priced at $275 and $235 respectively.

Processor Clock Speed Uncore Clock L2 Cache L3 Cache TDP Price
AMD Phenom II X4 940 3.0GHz 1.8GHz 2MB 6MB 125W $275
AMD Phenom II X4 920 2.8GHz 1.8GHz 2MB 6MB 125W $235
AMD Phenom 9950 2.6GHz 2.0GHz 2MB 2MB 140W $174
Index Phenom II's Secret, In Pictures
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  • Beno - Monday, January 12, 2009 - link

    fanboys help keep them alive.
    if more ppl started looking at AMD again, then Intel will be scared, so us the consumers will be happy because of prices.

    intel has been greedy and overpriced their c2 because there was no competetion at that time.
    Reply
  • garydale - Friday, January 09, 2009 - link

    I generally buy AMD processors for two reasons. The first is that I am not a gamer so I'm looking for cost-effective business application solutions. I'd rather double the memory than increase the processor speed, so AMD works well at the price points I build to.

    Secondly, I believe in the need for competition. With the power PC processor virtually absent from the consumer market and there being little else to choose from for the desktop market, AMD is Intel's only real competitor. So long as AMD has chips that are good enough to compete with Intel's on price/performance, I prefer to buy them.

    If Via got their Cyrix processors up to a decent speed, I might be tempted to switch to them, but let's face it, they don't really compete in this market. So in a two-way race, we need to put our money behind the underdog to prevent a monopoly.

    I've been buying ATI cards too for similar reasons. Nice to see that AMD's making advances in both areas.

    To be clear, I've got nothing against Intel, at least not since the Pentium fiasco, but I think everyone will agree that having multiple firms competing is better for consumers than having one company dominate (Windows 95, 98, Millenium Edition, Vista come to mind). :)
    Reply
  • aeternitas - Friday, January 09, 2009 - link

    Much of your post should go next to the Webster definition of "AMDfanboi"

    If you want true competition, buy the better product. I got my sweet A64. I will now consider P2 over a C2D, but because of price/performance/watt alone.
    Reply
  • Certified partner - Friday, January 09, 2009 - link

    "Blender is one of the few tests that doesn't strongly favor the Core i7, in fact it does not favor them at all. Here the Core 2 Quad Q9650 is the fastest processor, followed by the Phenom II X4 940 and the Phenom II X4 920."
    http://www.techspot.com/review/137-amd-phenom2-x4-...">http://www.techspot.com/review/137-amd-phenom2-x4-...

    "Blender shows Phenom II less competitive than the other 3D rendering tests we've seen thus far."
    http://www.anandtech.com/cpuchipsets/showdoc.aspx?...">http://www.anandtech.com/cpuchipsets/showdoc.aspx?...

    Both can't be true. Explanations would be highly appreciated. I suggest, that anandtech ask techspot about the test settings. Blender is capable of using several threads but I'm not sure wether the optimization is automated. Please, play with the settings. For example, 8*8 (render) tiles can benefit from 8 threads while 1*1 can't.
    Reply
  • Max1 - Friday, January 09, 2009 - link

    How much money has paid Intel to you for this "testing"? You have tested productivity of processors only on two games. In both games productivity of Core 2 is above. In one of them much more above, but it happens seldom. Other tests show, that productivity of Core 2 Quad in part of games is above. In part of games productivity Phenom II of same frequency is above. Why there is so a lot of coding and synthetic tests where Intel is faster, and as always there are no other applications? Why you continue to say lies, as earlier liars for money of Intel that Northwood is ostensibly faster, than Barton. Reply
  • strikeback03 - Friday, January 09, 2009 - link

    I'm surprised how long it took the fanbois to start commenting on this article. Didn't really get rolling until several pages into the comments. Reply
  • JimmiG - Friday, January 09, 2009 - link

    Bit disappointing that it's still slower than Core2 clock for clock. But given the performance of the original Phenom, I think the CPU performs as expected. A big leap for AMD. Unfortunately for them, Intel made an even bigger leap when they switched from Netbust to Core2.

    Also a bit concerned about this supposed "backwards compatibility". Many of the original 790FX boards, my M3A32-MVP Deluxe in particular, will not work with AM3 CPUs because Asus does not plan on releasing a BIOS update. Of course that's the fault of second-rate mobo companies like Asus, and not the fault of AMD. I'll probably end up getting a DDR2 PII-940 to replace my X4 9650, but I'll wait until the prices have dropped some.
    Reply
  • anandtech02148 - Friday, January 09, 2009 - link

    Just wait till Am3 socket comes out, Intel will have to make a slight cheaper version of x58chipset. Is that sweat i see on their forehead?
    Amd buy Via's Nano and give them a 2 prong attack.
    Reply
  • RogueAdmin - Friday, January 09, 2009 - link

    AMD has gone a long way to improving the performance of its processors, and everyone should go out and buy them. They need our support, and without it we will have to put up with whatever Intel decide to give us. And everyone here I think remembers the P4 days, let them not come again!
    The AM2 /2+ /3 platform is by far the easiest upgrade option. No need to worry if your NB chipset supports the latest FSB or RAM, because its all integrated into the CPU. A feature than Intel has copied in its new i7. Along with the monlithic quad core design, and level 3 cache. Also do not forget that AMD released the first x86-64 CPU, and intel basically complied to its x86-64 code to be compatible with the software developed for it.
    i7 is fast, very fast. But do you need that kind of performance in your everyday life? i7 is designed for workstation's hence the benchmarks of video encoding and 3D applications. Gamers would be better off getting a top of the line GPU. Is your CPU 100% utilized 24/7?
    I saw a comment about the 2 year old Core 2 Quad being faster, only in Far Cry 2, that one test. And I would rather play Crysis anyday.
    Since its release Intel has tweaked the performance of these with new cores no end.

    Sorry I digest.... lol

    Keep things competitive, buy AMD. Fanboy or no, let the price wars rage on.

    Reply
  • aeternitas - Friday, January 09, 2009 - link

    1. Most people use their everyday system to *work* too.
    2. Dont compare i7 to P2. Youll just look like youre really reaching and a fanboy.
    3. You dont -Need- anything better than a A64 for everyday tasks. Depending on how long you wanna wait though, you will go to a better system. That point about not -needing- better hardware has always been ridiculous and only applies to grandmas and people that use the computer for browsing and music. Those people dont care about this area in computer so its moot!

    P2 is great, but be realistic. Its competing against C2 right now. Comparing technicalities and -who was firsts- doesnt provide more FPs in anything. It just makes for flame fodder. The numbers speak for themselves and I think this article did a good job in putting the P2 in its place. As a great alternative for people looking to upgrade from older than C2 hardware.
    Reply

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