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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  • rudolphna - Thursday, January 08, 2009 - link

    Hey anand, do you think you could grill AMD and see if you can get out of them which chips will be made at the upcoming Malta, NY fab facility? Will it be PII or maybe bulldozer? Reply
  • mkruer - Thursday, January 08, 2009 - link

    Anand, I do alot of paring and although the recovery rate is good, i would like to see the results for creating a par2 file. Reply
  • Natfly - Thursday, January 08, 2009 - link

    I'm glad AMD is somewhat competitive in the quad core realm but I just cannot get over how blindingly fast the Core i7s are. It is incredible.

    I hope AMD can make it through, for consumer's (and my stock's) sake. This is a step in the right direction.
    Reply
  • xusaphiss - Thursday, January 08, 2009 - link

    Come on, guys! I like a competitive market as much as the next guy but AMD is a whole generation behind. They should have had these when the 45nm C2s came out!

    AMD is lapped!

    It's time for them to die!

    CPU standards will only go down if they actually resort to third-party distribution!

    Their video cards are always run hotter than NVIDIA and just less stable and overclockable. The only way they was able to stay alive in the race was pitting two of their GPUs against one on one board. NVIDIA hasn't even begun using DDR5 yet!

    Intel and NVIDIA is not really receiving competition from AMD. AMD is just lowering standards.

    Reply
  • ThePooBurner - Saturday, January 10, 2009 - link

    PLAYSTATION THREE is that you? Reply
  • aeternitas - Thursday, January 08, 2009 - link

    We would not of had C2D for years, if not for AMD. Please sit down your logic is flawed. Reply
  • Kroneborge - Thursday, January 08, 2009 - link

    Oh, let's hope AMD doesn't die. Or you can add a couple hundred on to the price of all your favorite Intel processors lol. Reply
  • Genx87 - Thursday, January 08, 2009 - link

    This one is simply not going to cut the butter by the middle of 09. True they are cutting into the Core 2 Duo's performance advantage. It still for the most part falls short. And I didnt see this thing really challange the i7 which will be Intels flagship chip by the end of 09. I dont know about AMD's future chips. But the Phenom needs an arch replacement for AMD to compete with Intel. Reply
  • JakeAMD - Thursday, January 08, 2009 - link

    I would suggest an amazing PC experience is about far more than benchmarks or the performance of one component. Some benchmarks today are at risk of losing relevance to real application performance. For example, performance on 3DMark Vantage scores don’t necessarily translate into a better gaming performance. Also, the CPU-only approach to video processing performance is now thoroughly outmoded, as that should be offloaded to the GPU. The Dragon platform technology is really within the budgets people are affording themselves today and we’re doing a better job of serving the real needs of the PC market today. So I would ask you – Is $1000 or more worth the performance difference?
    Reply
  • Genx87 - Friday, January 09, 2009 - link

    I am looking at these gaming benchmarks which is the most intensive thing I do on my computer. My 180 dollar E8400 is cheaper and faster.

    On the server side the i7 looks more attractive for my virtualization and sql server upgrade project. Where $1000 is pennies on the dollar. Though when you factor in total system cost it is usually not even that much.

    Anyways the i7 will come down in price over the course of 09 as a consumer friendly platform is released and the cost of DDR3 falls as production ramps. So it wont cost 1000 more for an i7 system for long. And I question whether an i7 system costs that much more now.

    Reply

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