Same Size, but Twice the Cores

Obviously the biggest improvement Yonah offers over Dothan is the fact that it’s dual core.  But where things get interesting is that thanks to Yonah’s 65nm process, a dual core Yonah die is about the same size as a single core Dothan die - in other words, it costs Intel just as much to make a dual core Yonah, as it did for them to make a single core Dothan. 

A major reason the die size didn’t really go up much is because although Yonah has two cores, its L2 cache size remains unchanged at 2MB.  Unlike the Pentium D, Yonah’s 2MB L2 cache is not split into two discrete 1MB caches, it is actually one whole 2MB cache that is shared by both cores.  This is a very important distinction, as it means that Yonah is far from just two Dothans stuck together. 

There are other architectural enhancements to Yonah that will give it a performance advantage over Dothan.  Below is an excerpt from our IDF coverage of Yonah, detailing what we know about the new CPU:

Making Pentium M more "Media Friendly"

All of the major performance improvements to each of Yonah's cores seem to revolve around SIMD FP and FP performance, two of the Pentium M's present day weaknesses in comparison to the Pentium 4.

The first improvement is that now all three of Yonah's decoders can decode SSE instructions, regardless of the type of instruction. Improving the decode width of the processor is a quick way to improve performance.

Next, SSE/SSE2 operations (not sure if all can be, but at least some) can now be fused using the Micro Ops Fusion engine of Yonah. At a high level, the benefit here is increased performance and lower power consumption, we'll get into architectural details of why that is when we eventually sink our teeth into Yonah next year.

Each of the two cores in Yonah have also received support for SSE3 instructions much like the Pentium 4 E [Prescott].

And finally there have been some improvements to Yonah's floating point performance, although Mooly would not say exactly what's been done. Curiously, Mooly referred to the floating point performance improvements as specifically made to improve gaming performance. Intel may have grander plans for Yonah than once thought...

The SSE/FP optimizations are all being grouped into what Intel is calling their Digital Media Boost technology, yes the names seem to get worse and worse as time goes on - but at least the functionality should be good.

We started out this article talking about the Pentium M’s shortcomings in digital media applications, and Intel has begun to address them with the architecture of Yonah, but the real question is - how effective have their efforts been?

Index Yonah vs. Dothan
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  • JoKeRr - Friday, December 09, 2005 - link

    http://www.notebookforums.com/showthread.php?p=147...">http://www.notebookforums.com/showthread.php?p=147...

    a new model of toshiba with yonah @ 2ghz, 2x512ddr2 667 annd x1400 graphics. Very interesting.

    Obviously yonah with 2x512mb ddr2 667 should perform better overall than ddr2 533.

    Similar to how dothan with ddr2 533 completely smokes out dothan at same speed but ddr2-400 or ddr333 (and surprisingly many manufacturers adopted that, example: sony FS toshiba m50 etc... stupid choice for the manufactures, not to mention turbocache or hypermemory will suffer a lot as well due to slower access to system memory).

    So when is the official release date for Yonah based lappy?? and where's the Part II of Yonah article??

    Thanks again AT, great job.
    Reply
  • IntelUser2000 - Monday, December 12, 2005 - link

    quote:

    a new model of toshiba with yonah @ 2ghz, 2x512ddr2 667 annd x1400 graphics. Very interesting.

    Obviously yonah with 2x512mb ddr2 667 should perform better overall than ddr2 533.

    Similar to how dothan with ddr2 533 completely smokes out dothan at same speed but ddr2-400 or ddr333 (and surprisingly many manufacturers adopted that, example: sony FS toshiba m50 etc... stupid choice for the manufactures, not to mention turbocache or hypermemory will suffer a lot as well due to slower access to system memory).

    So when is the official release date for Yonah based lappy?? and where's the Part II of Yonah article??

    Thanks again AT, great job.


    It was weird how single channel DDR2-533 is faster than dual channel DDR2-400 for Dothan. It seems the chipset doesn't take advantage of dual channel at all, so getting faster single channel stick is better than slower dual channel. So I assume it will be same for Yonah.

    Yonah will be released Jan 5, 2006 at CES(some trade show I heard).
    Reply
  • Furen - Thursday, December 15, 2005 - link

    Two DDR channels are bottlenecked by the FSB. The P4 can use dual-channel DDR effectively because of its much higher FSB. Reply
  • cryptonomicon - Saturday, December 03, 2005 - link

    I think yonah is a nice option for low power compact notebooks. As we can see here it doesnt really compare against the desktop amd X2 parts, but will line up good against mobile duel semprons and turion right? Also to be noted is that it has a low clock speed. How will it overclock?.. this interests me greatly. Reply
  • IntelUser2000 - Monday, December 05, 2005 - link

    quote:

    I think yonah is a nice option for low power compact notebooks. As we can see here it doesnt really compare against the desktop amd X2 parts, but will line up good against mobile duel semprons and turion right? Also to be noted is that it has a low clock speed. How will it overclock?.. this interests me greatly.


    Actually the highest end will initially be available at 2.17GHz, and a quarter later there will be 2.33GHz. There will be "Extreme Edition" like versions that are clocked 1 or 2 speed grades beyond the 2.33GHz, so 2.5 or 2.67GHz. Of course the "EE" versions will be higher power consumption(Actually its officially called E).
    Reply
  • snorre - Saturday, December 03, 2005 - link

    Are you trying to make "Yonah" look better than it really is (another Intel lemon) perhaps?

    And did you check for CPU throttling activity in your power consumption tests?
    Reply
  • Zebo - Friday, December 02, 2005 - link

    Everyone keeps talking about power consumption..I for one am not impressed. First of all with AMD - X2 in these tests is basically a overvolted part.. will run just fine at 2.0Ghz with 1.15-1.2V rather than 1.4V used here, lowering power signifigantly in "X2 turion" form when it gets here. Second, even so, the power consumption difference was'nt that great 109W vs 144W loaded.. It's not like comparing a P4 setup which sucks over 300W or double X2 power just to run here - you're talking 30-40W differential which will surley be addressed with the addition of DDR2 and unvervolting even AMD's 90nm processes. Nevermind what 65nm should add. AMD's not in trouble in this sector and Yonah gods greatest gift to the sector either. Since we can't buy product now it all moot anyway but either should make a great notebook.

    Since I don't like notebooks I wish anand had done some serious clocking here - after all I/we really care about is can intel reach 3.0+ Ghz with this process and Yonah for those of us who want to slam these chips on the desktop and as a precusor to Conroe.:) That's what intel really needs to perk my intrest again. 3+ Ghz to really compete again on desktop - I don't really see them getting back to Northwood vs Athlon XP day with this chip though no matter how high it clocks.


    Reply
  • Marmion - Thursday, December 08, 2005 - link

    Ever thought that speedstep wasn't used when compiling this test. Also we're basing consumption on the entire platform. This platform would differ compared to the Centrino platform - low power graphics, wireless and chipset. When idle, the Yonah core shuts down a core. It is fairly obvious that the consumption figure shown for the Yonah does not utilise speedstep. You can also underclock a Dothan if you want.

    I also find it difficult that the Turion X2 being cheaper than an equivelent Yonah, as shown by the price difference with AMD64 X2 over the single core equivelent, however the Yonah cost is equal to the Dothan at the next highest frequency, but the yonah has 2 cores - ie Yonah @ 2Ghz = Dothan @ 2.13Ghz.
    A Turion X2 will give up performance of the desktop equivelent to save power - its to be on the 90nm platform. So Yonah compared to a Turion X2 looks very good in all rspects (except 64bit but I don't need it so I don't care)
    Reply
  • IntelUser2000 - Monday, December 05, 2005 - link

    quote:

    First of all with AMD - X2 in these tests is basically a overvolted part.. will run just fine at 2.0Ghz with 1.15-1.2V rather than 1.4V used here, lowering power signifigantly in "X2 turion" form when it gets here.


    Who cares if X2 can be undervolted or overvolted?? Its not. That's default voltage of X2's. By under or overvolting it you are essentially putting it out of spec. Probably Yonah can be undervolted too. Whats your point here??? Plus DDR2 does not consume that much less power, since DDR2 clocks higher. I have even seen presentations that say 533MHz DDR2=400MHz DDR. Though its likely that's wrong, it shows that DDR2 isn't low power as you think.

    For those who thinks dual core Turions with DDR2 would make it lower power. No, because the DDR2 would be at 667MHz, NOT consuming less than DDR400, plus it will be dual channel, unlike the single channel on the current Turions, ACTUALLY consuming MORE power.

    People are essentially dumb here since most people almost assumes Yonah is a desktop chip. And people whos saying Yonah MAY be competitive at 2.6GHz, there WILL be 2.5-2.67GHz versions on "Extreme" ones. That's gonna be something as it would be higher clocked than X2's.

    DDR2 DOES NOT have power consumption advantage since it CLOCKS MUCH HIGHER THAN DDR. The tested configuration DOES NOT use a mobile chipset.

    AMD has NO PROCESS advantage by using SOI, since at 90nm and 65nm process, Intel is superior in leakage current at SAME transistor speeds for BOTH process WITHOUT using the wonderful SOI some are touting.

    65nm DOES NOT NECESSARILY LOWER POWER OVER 90nm, look at initial AXP's at 130nm, called Throughbred, they were about 10% less power and no overclock.
    Reply
  • Zebo - Wednesday, December 07, 2005 - link

    Claim down fanboy.. geez even your user name says it you don't have to keep broadcasting it. It's default for a desktop chip, it's overvolted in the sense that anands substituting a desktop chip and competing with a notebook product here...as in the dual turons slated for lappys will be 1.2 or 1.25, not 1.4 futher reducing power..just like turions today vs regualar desktop A64's. If you really think Dual turions will be 1.4 then we have nothing further to discuss.


    And you're just wrong about DDR vs DDR2
    http://www.samsung.com/Products/Semiconductor/DRAM...">http://www.samsung.com/Products/Semicon...Info/101...




    Reply

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