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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Furen - Wednesday, November 30, 2005 - link
Silicon on Insulator helps with current leakage, though. The problem for AMD, as I see it, is the delay of its 65nm process.forPPP - Wednesday, November 30, 2005 - link
Interpolating results shown in this article, I think we won't see Turion Dual Core with more than 2.0GHz or maybe even 1.8GHz for now, because it will consume much more power. That's why Turion will be behind it till AMD gets to 65 nm. But then Intel will have new architecture.Cygni - Wednesday, November 30, 2005 - link
Heres a quick summary of my thoughts:Best mobile proccessor option ever produced. Would be silly not to get one with your next laptop. But it doesnt have the muscle for the desktop. Nuff said.
Miggle - Wednesday, November 30, 2005 - link
gaming wise, its looks good. Altho it would be more fair to compare a 2ghz yonah to a 2ghz Athlon X2 /w 2MB L2, being within 5% of 3800+ is very good already, considering that its a notebook cpu. the desktop version may even surpass Athlon64. I sure hope AMD also has something up their sleeves. Exciting match!defter - Wednesday, November 30, 2005 - link
"Altho it would be more fair to compare a 2ghz yonah to a 2ghz Athlon X2 /w 2MB L2"Actually current comparison is fair, since Turion has only single channel memory controller. 2*512KB + dual-channel memory controller Athlon64 achieves about the same performance as 2*1MB + single-channel memory controller.
Furen - Wednesday, November 30, 2005 - link
Dual-core Turions will (supposedly) be socket S1, which will have dual-DDR2 channels.michaelpatrick33 - Wednesday, November 30, 2005 - link
How is it good to be within 5% of a 3800? The 3800+ has only 1024L2 cache total. Additionally, this is their 65nm product compared to a 90nm product and it still doesn't match it in performance? I was expecting more from Yonah than this. AMD already has dualcore notebook Turions coming in Q1 '06 so Intel does indeed look further behind.Additionally, I am not too fond of Sysmark as a performance indicator either way, but still I don't think AMD needs to run around panicing at this point.
Furen - Wednesday, November 30, 2005 - link
If the FX-60 is a 2.6GHz dual-core then AMD will have something that will more than match any Yonah thrown at it (a 2.7GHz or so Yonah could conceivably beat it, I suppose). Yonah really does make things a lot more exciting though, since at least Intel is within striking distance.anandtechrocks - Wednesday, November 30, 2005 - link
You are comparing the most powerful AMD FX processor with a mid-range mobile chip? What does this prove?tfranzese - Wednesday, November 30, 2005 - link
Considering the single core Dothan at 2.0 GHz runs about $300 I don't see how you could say that a dual-core Yonah of the same clock is 'mid-range' especially for a notebook. I highly doubt the chip previewed today will launch at or below that price point, and probably much higher.