Nehalem Micro Architecture: Intel Embraces the IMC and IGP

Surprisingly, Intel gave away quite a few details about Nehalem. Although Nehalem is still based on the 4-issue Core architecture, it takes "multithreading" to a whole new level. First of all, Nehalem can contain up to eight cores per die. Combined with 2-way Simultaneous Multi-Threading (SMT or Hyper-Threading), you'll have the ability to execute up to 16 threads on one chip!

Nehalem will also use multi-level shared cache. Pat Gelsinger indicated that only the highest level of cache would be shared, meaning that Nehalem could very well have a similar cache hierarchy to AMD's Barcelona (independent L1/L2 caches per core, but a shared L3 cache). The power of each core is "dynamically managed" which might indicate that Nehalem goes one step further than AMD's Barcelona core: it could have independent power planes.

Nehalem will no longer use a FSB but a serial point to point interconnect. Even more revolutionary is the fact that Nehalem will have an integrated memory controller (IMC) and that the number of serial interconnects is variable (Intel's version of "HyperTransport"). Another potentially groundbreaking move is that some Nehalem CPUs will have a GPU integrated (Intel's version of "Fusion"). With an integrated memory controller, new interconnect, and potentially integrated graphics, Nehalem will obviously require a new socket.

Intel would not give any more detail, but it is clear that the GPU will not be high-end (that would require too much power); more likely it will be a kind of midrange (or even low-end depending on your perspective) solution. Intel would not confirm this, but it seems pretty clear to us that Xeon DP and desktop products will probably have an IMC that supports DDR3. Xeon MPs will probably have an IMC that supports registered FB-DIMMs with DDR3. Nehalem should first be available in the second half of 2008 as Intel talked about "production ramping in 2008, with full production in 2009".

Final Words

Continuing the trend started by the "new Intel", today we were given a ridiculous amount of information about Intel's coming microprocessor architectures. Obviously part of today's announcements were intended to pre-empt any excitement about AMD's Barcelona architecture, but Intel is doing the right thing. It's sharing a very forward looking roadmap with the public early on in order to rebuild trust and confidence, especially after what happened with NetBurst.

This is the exact approach we would like AMD to embrace as well, keep the public informed, especially if you have exciting things to talk about. We understand the desire to try and protect trade secrets, but with the complexity of modern processors and the amount of information that gets shared between partners, not to mention "corporate espionage", it seems likely that Intel and AMD already more or less know what their competitors are planning. Changing course late in product development is nearly impossible to accomplish, and especially when current products begin to lag behind the competition we would expect companies to try to garner interest by talking about the future.

Looking to the future, one thing that is clear is that multi-core solutions are truly becoming the norm. We still haven't managed to realize the potential of even dual core solutions with many applications (particularly games), and with quad core and octal core processors in the pipeline the need for software to become more multithreading-friendly is reaching a critical stage. The good news is that we're beginning to hear a lot more about multithreaded software engine designs, and we are even beginning to see some of the fruits of these labors.

Naturally, without any actual hardware test, it is impossible to say right now whether Intel or AMD will come out on top with their next-generation processors. Regardless of which company "wins", the best news is that it appears the cutthroat competition will continue for the time being. All you have to do is look at current processor prices to appreciate the importance of competition, and we're certainly looking forward to the day when quad core and higher systems fall into midrange and lower price brackets!

Penryn Enhancements, Continued
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  • cornfedone - Wednesday, March 28, 2007 - link

    Intel knows they are about to get punished again by AMD so they are greasing the skids to get the media hype they need to delude consumers into believing Intel's products will still be competitive after Barcelona, when the facts prove otherwise.

    Hey if nothing else, Intel is good for a laugh. It's nice to see those criminals squirm for a change. It's only gonna get worse when they get to court and AMD proves that Intel violated law over and over and over again in their obsession to eliminate competition.

  • fitten - Thursday, March 29, 2007 - link

    Intel couldn't, and wouldn't, eliminate AMD. In fact, Intel would probably float AMD a loan, if it came to it, in order to keep AMD afloat simply to avoid the backlash of other potential monopoly charges should AMD disappear.

    Plus, Penryn is the next thing up for Intel, supposedly out around the time as AMD's Barcelona (later this year - which is 2007). Nahelem is out in 2008-ish and does even more (according to the dates listed, a year before AMD's Fusion which is slated for 2009).

    All I can do is laugh giddily because I have no allegiance to either CPU maker. I simply buy what is the best bang for the buck (for a long time now, it was AMD and I've had about a dozen AMD boxes) which, for the next couple/few years, looks like it's going to be Intel. If nothing else, the competition will kick AMD into overdrive and competition will get even hotter... and I benefit regardless of who is on top.
  • johnsonx - Wednesday, March 28, 2007 - link

    ah, Cramitpal, how we missed you!
  • Crassus - Thursday, March 29, 2007 - link

    Oh year, those were the days ...
  • amdsupport - Wednesday, March 28, 2007 - link


    Intel knows they are about to get punished again by AMD so they are greasing the skids to get the media hype they need to delude consumers into believing Intel's products will still be competitive after Barcelona, when the facts prove otherwise.

    Congratulations! You've just constructed the 4millionth floor on the edifice of stupidity.

    Seriously...there is no basis for claiming AMD's new stuff(or rather, refreshed) will exceed Intel's offerings. ">Anandtech themselves claimed in a previous article that "AMD could come close to offering something competitive to Intel." That sounds like AMD will only bring themselves back in line with Intel's current offerings...not exceed or punish as you claim.

    As far as the court proceedings go...any result from it at best would result with a simple "slap on the wrist" punishment at best.

  • Justin Case - Thursday, March 29, 2007 - link

    If the numbers I've been hearing are right (and they probably are), AMD will get ahead of Intel in terms of floating-point performance, and will extend its lead in terms of memory performance (Intel's real Achilles's heel in HPC and servers).

    On the desktop, they'll be more or less matched with Barcelona, but AMD's Fusion could tip the scales in its favor for gaming systems.

    Intel will probably retain its lead in mobile platforms, but I don't have much real data on Barcelona's power-saving features, so I really can't say for sure.

    Penryn should put Intel back in the lead on the desktop (Fusion being the unknown factor here) and bring them pretty close in servers (Intel is still trying to push Itanium, so there are a lot of internal conflicts about server-oriented improvements, which gives AMD a bit of slack).

    All in all, it's business as usual: Intel is better at manufacturing and optimization, AMD takes more risks with design (and, with all the great engineers they hired from DEC, Intel, IBM, ATI, etc., they seem quite capable of pulling it off).
  • Phynaz - Wednesday, March 28, 2007 - link

    Is the sound of piss running down Hectors leg.
  • HammerFan - Wednesday, March 28, 2007 - link

    I really like to see this kind of information, that neither company is sitting down and saying "enough's enough." I wonder though, if Intel is going to use their own graphics systems in their all-in-one chip, or if they'll turn to nVidia/ ATi for a graphics solution. As for chipset manufacturers, how well they do will largely depend on the features they can pack into their SB's IMHO, as that's largely what I look for when I want a new MB, since performance from board to board doesn't vary that much anyway.
  • chucky2 - Wednesday, March 28, 2007 - link

    Yeah, I'd myself really like to see AMD, Intel, and nVidia adding support of native 1394b (Firewire 800) in their chipsets, so products like that can start moving forward.

    Having eSATA would be nice as well...

  • tumbleweed - Wednesday, March 28, 2007 - link

    The earlier a company discloses what their plans are, the earlier they get feedback on how the public likes or dislikes some of their plans.

    Think about how much money Intel could have saved if they'd realized much earlier how badly the public hated RAMBUS.

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