Intel Yonah Performance Preview - Part I: The Exclusive First Look at Yonah
by Anand Lal Shimpi on November 30, 2005 2:50 AM EST- Posted in
- CPUs
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?
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NeonAura - Wednesday, November 30, 2005 - link
Yonah seems pretty good. Looks to be doing a good job. But I wonder, how much is that 2.0 ghz Yonah chip going to cost? Retail at launch: $400-$450 is my guess. An AMD X2 3800+ is cheaper than that by a bit, and barely sacrifices any performance. The thing is, AMD is just sitting here watching Intel like Intel used to watch them. AMD is waiting for Intel's next move, meanwhile they're ready to start pimping out some fine chips. The Yonah is going to be released Jan-Feb 2006, while the X2's were released June 2005.AMD will be ready for Intel, Intel just doesn't know it yet. I'm not a fanboi, but Intel is going to have to throw up some hail marys to take down AMD with the Yonah, Conroe or whatever chips they may have coming. Because AMD hasn't been sitting on their behinds for the past six months. AMD is just being secretive, they want to surprise Intel by putting out their chip that they haven't really talked about right at the same time as Intel puts out Yonah.
AMD will be playing the same game as Intel soon enough, and Intel better put these chips as cheap as they possibly can or they'll be taken down.
mav99 - Wednesday, November 30, 2005 - link
1. intel has confirmed that merom will be compatible with the new upcoming yonah motherboards. you only need a bios update.2. the chipset should support ddr2-667 to match the 667 fsb. why did they use ddr2-533 for the article?
yzkbug - Wednesday, November 30, 2005 - link
My main concern is whether new Conroe/Merom will be compatible with Yonah socket. I hate upgrading the motherboard every time I upgrade my CPU. AMD is definitely better in this respect.Zebo - Friday, December 2, 2005 - link
Well times are changing- No more 5 years of socket A. AMD doing like Intel nowerdays switching sockets every year..year and half. M2 is coming next year. Before that we had 940 for FX's then 754 and now 939...fitten - Thursday, December 1, 2005 - link
I typically upgrade my motherboard when I upgrade the CPU as well.... even on my AMD systems. By the time I'm ready to upgrade the CPU, there are typically better boards (more features, better chipset, etc.) around to take better advantage.Example, if you bought a Via chipset board with your first Athlon64, it's probably worth spending the extra $85 for a new motherboard to get an nForce4 or better chipset with your new CPU. You can probably get an increase in performance just keeping your old CPU and upgrading the motherboard... especially in features.
Shintai - Wednesday, November 30, 2005 - link
Merom yes, Conroe..will both yes and no. Conroe will use 1066FSB, Meron/Yonah 667FSB. So a Conroe on a Yonah board might be slow due to FSB and multiplier.Leper Messiah - Wednesday, November 30, 2005 - link
Sooo...yeah. Intel's possible $500+ notebook part thats coming out next year is competive with AMD's currently out $325 desktop part in basically all things, ya know. Except that price thing, and that whole 64-bit thing. Be interesting to see the OC numbers on this and how high they want to take the speeds. As of right now though, meh.fitten - Thursday, December 1, 2005 - link
Those are pretty good things for a chip destined for your laptop to have... which is where that X2 won't be going (for obvious reasons).If you look at this article as being a comparison of desktop systems, then it is pretty ho-hum. If you look at it like you'll be able to have this in a (hopefully) 4-5 lbs laptop and still get over 3 hours (maybe even up to 5) off a battery while you are on the road, then it is a bit more interesting.
Leper Messiah - Thursday, December 1, 2005 - link
See, I (and quite frankly most people) don't even need dual core performance in a laptop. The only way I could actually see my self going out and actually spending money on either one, Yonah or dual core turion is if it was to be my only computer. I don't understand why lap top users need this much power. And I guarentee Intel will make it uber expensive.stateofbeasley - Thursday, December 1, 2005 - link
http://www.theinquirer.net/?article=27770">http://www.theinquirer.net/?article=27770The price points are the same as existing Pentium M processors. I don't know why people make the assumption that Yonah will somehow be super expensive, because that's just not true.