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
Intel, oh Intel, how uninteresting your processors have been to us for so long now. Where have the days of the Northwood gone? Prescott brought us a minor bump in clock speed, minor increases in performance, and more importantly - major increases in power bills. But if any company can go down the wrong path for five years and still come out on top, it’s Intel. So starting next year, we’ll start seeing a new Intel. A more power conscious Intel and to kick it all off will be Intel’s first Earth-friendly dual core processor: Yonah.
As the successor to the current Pentium M (Dothan) and the predecessor to next year’s Conroe, Merom and Woodcrest cores, Yonah is a very important chip. As a mobile processor Yonah will bring dual core to thin and light notebooks, basically anywhere you’d find a Pentium M, you’ll now be able to find two Pentium Ms. The implications for mobile performance are huge, as multitasking on notebooks has rarely been all that great of an experience. At the same time, Yonah is so much more than just a dual core mobile processor - it’s a predictor of the performance of Intel’s next-generation desktop micro-architecture. Sure, it won’t have all of the architectural bells and whistles that we’ll see when Conroe debuts at the end of next year, but it’ll have many and that makes it a reference point.
The problem with the Pentium M architecture has been that although it’s traditionally done well at office tasks and obviously in the power consumption department, it has lagged behind the Pentium 4 and Athlon 64 when it comes to FP intensive applications such as video encoding, and to a lesser degree, 3D gaming. With Yonah, Intel has promised to address those performance issues, and even more so with their next-generation micro-architecture later next year. But we tend to want to see things for ourselves, and Yonah will at least give us an indication of how things have improved since Dothan, and whether or not Intel is on the right track to replacing the Pentium 4.
By now we’ve hopefully stressed the importance of Yonah, and there’s just one more detail to mention - we have one.
The Platform - Yet Another Socket
While the launch of Yonah still won’t be until January of next year, we’ve had a chip for the past month, unfortunately, we haven’t had a motherboard to stick it in. We finally got one two days ago, which is why you’re seeing this article now, instead of more pictures of our Yonah posing alongside the Xbox 360. The problem is that Intel seems to have changed sockets once more, meaning that Yonah is not backwards compatible with the original Pentium M socket.
If you’ll remember back to the introduction of the Pentium M, Intel introduced a brand new socket for the processor: Socket-479. Back then, the desktop Pentium 4 still used the pin-based Socket-478, so the different pin-out was a bit of a pain to deal with as we all wanted to be able to stick Pentium Ms in our Pentium 4 motherboards.
The Yonah socket is still a 479-pin interface, however the pin-out has been changed once more, and of course Yonah won’t even physically fit into any current Pentium M motherboards. Instead, you’ll need a brand new motherboard with a brand new chipset. So if you invested in any of the handful of desktop Pentium M motherboards that were released over the past year, you’re unfortunately out of luck.
Yonah (left) vs. Dothan (right) - Note the different pin-out
What’s this about a new chipset? Well, it’s not exactly a new chipset, rather it’s Intel’s mobile 945 chipset - the mobile version of the desktop chipset we’ve had for quite some time now. The platform we’re testing on in particular uses Intel’s 945G chipset, with integrated graphics, but of course we aren’t too interested in integrated graphics performance so we’ll be using the PCIe x16 slot on the board.
While we can’t tell you who makes the motherboard we’re testing with, the important thing to note is that it is a desktop motherboard made specifically for Yonah. It’s got a single PCIe x16 slot, meaning you don’t have to rely on integrated graphics, and all of the bells and whistles you’d expect from a desktop motherboard; this could very well be the heart of your next system.
We’ve been hearing that Pentium M based desktops will become a lot more common next year, and this motherboard is definitely an indication of that.
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stupid - Wednesday, November 30, 2005 - link
Since the closest CPU AMD has that is similar the Yonah is the Athlon 64 X2 3800+ I figured it may be interesting to see how the Yonah would compare to the Athlon 64 X2 3800+ when using the 65nm process. This will happen next year, but I figure crunching some numbers now may shed some light as to its possible performance in terms of TDP and power consumption. My calculations are simply conjecture and I am pretty sure it will raise questions regarding their validity. I must point out that I am not an electrical engineer, and I assume that calculations would be linear.So let's begin. First off, I will start by crunching numbers for the die shrink for the single core Athlon 64 from 130nm to 90nm. Why? Because the Athlon 64 X2 was introduced using the 90nm process. Going from 130nm to 90nm is a 30.77% reduction in size. A 130nm Athlon 64 has a TDP of 89, and a 90nm Athlon 64 has a TDP of 67. This is a reduction of 24.72%. So the decrease to TDP is about 80% of the physical die shrink. This is a baseline number used for the next series of calculations.
Okay, let's look at what might happen when the Athlon 64 X2 is shrunk from 90nm to 65nm. Going from 90nm to 65nm represents a 27.78% reduction in physical size (assuming nothing else is added to the core). The Athlon 64 X2 3800+ has a TDP of 89 (all other Athlon X2 has a TDP of 110), if it can be assumed from above that the reduction in TDP is 80% of the physical decrease, then 80% of 27.78% is about 22.22%. This means that the TDP will drop from 89 to 69. Let me make a dangerous assumption that power consumption will decrease by the same percentage TDP would decrease by. So a 22.22% reduction in power consumption would mean that going from 90nm to 65nm Total System Power when idle is estimated to be 85 watts, and under load would be about 112 watts.
Summary:
Yonah: Idle - 92 watts, Load - 108 watts
Athlon 64 X2 3800+ (65nm): Idle - 85 watts, Load - 112 watts
So what does this all mean?
When the desktop Athlon 64 X2 3800+ is migrated to the M2 socket and the 65nm process is applied, it's power consumption may be very close to that of Intel's mobile CPU the Yonah. Thus, a mobile version of the 65nm X2 3800+ could mean better thermal, and power consumption performance than the Pentium M.
Let me just repeat again, all this is based on simple calculations that does not take into account potential variables in the real world.
LET THE FLAMING BEGIN !!!!!!!!!!!!!!!!!
forPPP - Thursday, December 1, 2005 - link
Completely false assumption.Yonah idle = 92 W. Do you really think 92 W in ile for notebook is possible. Provided in article power usage is not for CPU but a few components. You should rather recalculate by assuming that at idle CPU takes 0 W.
So:
Yonah = 109 - 92 = 17 W (+ true idle, how much can it be 3-5 W ?)
Athlox X2 = 144 - 109 = 35 W (+ true idle, 10-15W ?)
22% reduction for 65 nm and you got 28 W, almost 65% more than Yonah. Taking into account proposed idle usage it's stil 50% more than Yonah.
But Turion use less power than Athlon 64, mostly because it's clocked lower (and can have lowe voltage).
I suposse Turion Dual 1.8 GHz will be at the same TDP as Yonah 2.13 GHz.
Furen - Wednesday, November 30, 2005 - link
Actually, even though going from 130nm to 90nm is about a 30% feature size reduction, the actual die size redution is closer to 50%. This is because each transistor is shrunk close to 30% in each of its two dimensions, meaning that it'll have about 49% of the area of a pre-shrink transistor (70% x 70% = 49%, though this is not absolutely exact). In truth going from the 144 sq mm Newcastle to the 84 sq mm Venice gives you a die-size reduction of around 42%, which makes sense considering that you can't shrink everything in proportion to the feature size. I would expect the 65nm die shrink to offer similar or slightly worse size reduction.Shintai - Wednesday, November 30, 2005 - link
Let me give you a hint. Remove the hueg GFX card etc before doing your calculations. A hint for you is that Yonah idle comsumes around 1-3W depending on speedstep setting.Anyway, you need to do better homework since your math is flawed by other systemcomponents :P
stupid - Wednesday, November 30, 2005 - link
I can understand that you want to only look at the power consumption of the CPU. However, the article does not provide a breakdown of power consumption used by each individual component. I've also stated that my calculation will be linear, so yes the results are a bit skewed.The calculations are meant to be quick and dirty, not scientific.
xenon74 - Wednesday, November 30, 2005 - link
Hm, you and all other are forgetting that Turion uses Athlon64 architecture BUT with different type of transistors for mobile use, that consumes even less power. Based on that, my approximation goes as follows:90nm Athlon64 3500+ @ 2,2GHz is in 67W TDP envelope, E4 rev
90nm Athlon64 X2 4200+ @ 2,2GHz is in 89W TDP envelope, E4 rev
Thats 43% increase in TDP for second core (or 22W). Both CPU's are using the same voltage.
90nm Turion64 MT-40 @ 2,2GHz is in 25W TDP envelope, E5 rev, 1,2V_core
I speculate that dual core Turion64 will be:
90nm Turion64 X2 MT-40 @2,2GHz in 36W TDP envelope.
stupid - Wednesday, November 30, 2005 - link
Yes, the Turion uses transistors that are more gear towards reducing power consumption whereas an Athlon uses transistors that are geared more towards performance. But you need to realize that the article is comparing the Yonah to the Athlon 64 X2 3800+ and not the Turion.Yonah cannot be compared directly to the Turion because that is comparing a dual core CPU to a single core CPU.
The point of my post is not to compare Intel's mobile solution to AMD's next mobile solution. It is to emphasize that given a mere die shrink AMD's dual core CPU based on the 65nm process is potentially almost as energy efficient as Intel's dual core mobile CPU. If this is true then you can make the assumption that a dual core Turion will be even more effiencent than the Yonah because the dual core Turion will most likely be based off of an already efficient desktop CPU, and will have transistors that are geared towards power consumption efficiency rather than performance.
Do you follow?
xenon74 - Thursday, December 1, 2005 - link
Yes it can be and was in a TDP manner! :P
I cannot compare future mobile chip to noexistent desktop X2 chip (there will be no Athlon64 3800+ X2 in 65nm, maybe Sempron). But I do understand your emphasization and assumption.
crotale - Wednesday, November 30, 2005 - link
What was the FSB for the Yonah platform in this test?Donegrim - Wednesday, November 30, 2005 - link
I don't think they said, but I think all DC Yonahs are 667 (quad 166), which is a bit slow.