Intel's Dual Core Strategy Investigated
by Anand Lal Shimpi on October 22, 2004 3:09 PM EST- Posted in
- CPUs
Dual Core Mobility
A while ago I asked Pat Gelsinger what was in store for the future of Pentium M with regards to threading, and he responded with multi-core. Thus it's no surprise to finally see Intel giving more details about Yonah (or Jonah depending on what part of the world you're from), the 65nm dual core successor to Dothan.
Yonah's dual core setup will be much more power optimized than what Smithfield will bring to the desktop, and in an effect, much more efficient. There's little information available about Yonah, other than it will most likely have a power and thermal balancing dual core setup, with the individual cores powering down when they're not needed. The idea here is to switch between cores not based on performance needs, but based on thermal and power needs. If one core happens to be running too hot, it can be powered down and the active workload shifted to a different thread running on the remaining core, thus reducing the problem of thermal density by effectively spreading the thermal load across two cores.
While Dothan was more of a small set of fixes and updates to Banias, Yonah is going to be a significant set of improvements to what we've seen in the past. Yonah has already taped out and Intel is slated to release the chip in 2006. Yonah will begin sampling by the end of 2005 and Intel expects it to ramp up to 50% of the performance notebook segment by the end of 2006.
Yonah's platform is codenamed Napa, which brings support for DDR-2 667 as well as the 667MHz FSB to help keep the dual core Yonah fed with data. Given that Dothan will ramp to 2.26GHz by the end of 2005, we can expect Yonah's clock speeds to be around there upon its launch.
Dual Core Servers
Most recently Intel announced that their only multi core enterprise product shipping in 2005 would be Montecito, the dual core version of Itanium 2. This is where the rumor of Intel not shipping any dual core chips until 2006 came from, as it seems that the first dual core Xeons won't ship until Q1 2006. Now as long as Intel's desktop chips don't face any further delays, there will still be dual core desktop CPUs based on Smithfield available by the end of 2005. Given Intel's track record lately, it would not be surprising to see these chips slip into 2006 as well though.
The first dual core Xeons appear to be nothing more than Xeon versions of Smithfield,
but Intel does list that more power efficient versions of the first dual core
Xeons will appear in the second half of 2006 - potentially including
some of the power management features that will be included in Yonah.
An interesting inclusion on Intel's dual core Enterprise roadmaps is the
mention of a Dual Independent Bus. The term Dual Independent Bus hasn't
been used since the days of the Pentium III to indicate the separation of the
internal L2 cache bus from the external Front Side Bus. However, we wonder if
the dual core Xeon's Dual Independent Bus may in fact be individual 64-bit
datapaths to each socket on a dual socket server. This way a pair of dual core
Xeons would have just as much FSB bandwidth per pair of cores as the present
day dual processor Xeons, which will end up improving performance tremendously.
The platforms that will enable dual core Xeon support will be Blackford and Greencreek for 2S (two Socket) systems, and the next generation Twincastle for 4S systems.
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HardwareD00d - Friday, October 22, 2004 - link
#16, The reason hyperthreading will be disabled with dual cores is because WindowsXP only support 2 processors right now. I'm not sure about Windows 2000, but Intel has said you should not enable HT with that OS.I heard that Intel is hoping that M$ makes a "patch" to XP so it will do 4 processors. AFAIK, Intel is waiting on that for the "official word" on HT in dual core.
thelanx - Friday, October 22, 2004 - link
So these are underclocked 3.8 prescotts? That could be prove to be a great overclock with water cooling maybe, as it'll be virtually garuanteed 3.8 GHz or more, just gotta make sure you've got adequate cooling.thelanx - Friday, October 22, 2004 - link
GhandiInstinct - Friday, October 22, 2004 - link
So for now it's just an advanced version of hyper-threading, instead of virtual cpus you have physical cpus, thanks Anand.sprockkets - Friday, October 22, 2004 - link
How are the 2 cpus connected with Intel? Why disable hyper-threading for having extra cores, oh well, guess it makes some sense. What then we could do is make 2 cores with a split amount of ALUs and FPUs.Jeff7181 - Friday, October 22, 2004 - link
#13... Water cooling won't be a necessity. Don't forget, with the increase in heat from dual cores there's also an increase in surface area for that heat to be dissipated through. I don't think you'll see a huge increase in CPU temperature at all. What WILL increase more is power requirements, and case temperate... as well as the temperature of the room the PC is in and probably the size of the heatsink.xsilver - Friday, October 22, 2004 - link
Anand, how did you measure power consumption from your last batch of reviews? hardware or software? links? thanksRegarding dual cores, aren't these cpu's going to be horrendously expensive to produce if they are basically 2x prescotts?-- and if there is 200w power consumption, isn't that mandatory water cooling territory?
Anand Lal Shimpi - Friday, October 22, 2004 - link
Jeff7181True, but I was mostly referring to 800MHz FSB chips, the 533MHz parts will still be available then too.
supertyler
You pretty much answered your own question there, monitoring user inputs are generally not CPU intensive tasks at all - in fact you could say that those tasks are mostly user limited :) A huge benefit to dual core (or SMP in general) is that if you have one renegade application that eats up a ton of CPU power, you still have a separate CPU that can continue to work for you during the interim. It is a tangible performance improvement, but one of few for desktop uses.
Marsumane
It's tough to say what's going on with AMD until we actually see more roadmaps. For now, they haven't increased clock speed all that much either, remember we're still at 2.6GHz at a maximum with the fastest non-FX Athlon 64 running at 2.4GHz. As far as building more fabs goes, they cost about $2.5B a piece and take quite a bit of time to build, I don't think that's exactly the quickest fix to the situation at hand :)
skunkbuster
Remember that Banias and Dothan are designed with clock speed limitations in mind, they need smaller manufacturing processes to actually reach higher clock speeds as they natively have very short ramping abilities. For more information take a look at my Banias or Dothan reviews.
GhandiInstinct
In a single threaded application, no they will not be any faster. In a game for example, two 3.2GHz cores will not be faster than a single 3.2GHz core.
Take care,
Anand
klah - Friday, October 22, 2004 - link
These will still be using 1.385V? If so, 200W+ power consumption?GhandiInstinct - Friday, October 22, 2004 - link
"The vast majority of applications on the desktop are still single threaded, thus garnering no real performance benefit from moving to dual core"Anand,
So two 3.2ghz cores will not be faster than one 3.2ghz core?