Barcelona Architecture: AMD on the Counterattack
by Anand Lal Shimpi on March 1, 2007 12:05 AM EST- Posted in
- CPUs
Final Words
When Intel launched its first Core 2 based microprocessors, the performance improvement was beyond revolutionary. It was the biggest single performance improvement we had seen from a new microprocessor in several years at that point. A large part of Core 2's success was its architecture, but you cannot ignore that it couldn't have come at a better time for Intel.
All Conroe, Merom and Woodcrest had to do was outperform Intel's aging and misguided NetBurst based Pentium 4 processors. Doing so proved quite easy for AMD, which had been doing just that pretty much since the 2000 launch of the processors. With no competition from within Intel, AMD wasn't really doing that much better. While the K8 was a strong architecture, it was getting old. Without any serious performance enhancing architectural updates since its introduction back in 2003, AMD left Intel with a stationary target to aim for. With each successive iteration of the Pentium M architecture, Intel came closer and closer to developing its own Athlon 64 killer, eventually culminating in the release of such a product - the Core 2 Duo.
It wasn't some mystical force of microprocessor design prowess that allowed Intel to pull ahead last year; it was a good architecture and excellent timing. Ironically enough, it was the same two elements that orchestrated much of the success of AMD's K7 and K8 architectures; they were both good designs released at times when the competition was at its worst.
In terms of actual product releases, the first incarnation of AMD's new architecture will be found in the next-generation Opteron due out at the middle of this year. AMD will initially launch at speeds ranging from 2.1GHz to 2.3GHz, but by the end of this year you can expect higher clock speeds. On the desktop, AMD's Agena core will be a Barcelona equivalent shipping at between 2.7 - 2.9GHz. Kuma will be a dual-core variant of Agena shipping in the 2.0 - 2.9GHz range.
Barcelona will be a success for AMD; the long awaited architectural update to K8 should yield significant performance improvements, especially in current areas of weakness for the K8 (e.g. video encoding). Our review of the Athlon 64 X2 6000+ showed that with aggressive pricing, AMD could come close to offering something competitive to Intel. At current prices, we suspect that Barcelona would be enough to close the gap between AMD and Intel. Chances are that we won't see bargain basement prices on AMD's new cores, but we'd expect that AMD would have to maintain a competitive market.
The real catch here is what happens after Barcelona; as we mentioned before, Intel's current successes were born out of steady but regular evolution of a good starting architecture. With yearly updates to the Pentium M, Intel achieved a snowball effect that proved difficult to stop. It would seem that a similar approach by AMD would be necessary to avoid sticky situations like the one it finds itself in today.
When Intel launched its first Core 2 based microprocessors, the performance improvement was beyond revolutionary. It was the biggest single performance improvement we had seen from a new microprocessor in several years at that point. A large part of Core 2's success was its architecture, but you cannot ignore that it couldn't have come at a better time for Intel.
All Conroe, Merom and Woodcrest had to do was outperform Intel's aging and misguided NetBurst based Pentium 4 processors. Doing so proved quite easy for AMD, which had been doing just that pretty much since the 2000 launch of the processors. With no competition from within Intel, AMD wasn't really doing that much better. While the K8 was a strong architecture, it was getting old. Without any serious performance enhancing architectural updates since its introduction back in 2003, AMD left Intel with a stationary target to aim for. With each successive iteration of the Pentium M architecture, Intel came closer and closer to developing its own Athlon 64 killer, eventually culminating in the release of such a product - the Core 2 Duo.
It wasn't some mystical force of microprocessor design prowess that allowed Intel to pull ahead last year; it was a good architecture and excellent timing. Ironically enough, it was the same two elements that orchestrated much of the success of AMD's K7 and K8 architectures; they were both good designs released at times when the competition was at its worst.
In terms of actual product releases, the first incarnation of AMD's new architecture will be found in the next-generation Opteron due out at the middle of this year. AMD will initially launch at speeds ranging from 2.1GHz to 2.3GHz, but by the end of this year you can expect higher clock speeds. On the desktop, AMD's Agena core will be a Barcelona equivalent shipping at between 2.7 - 2.9GHz. Kuma will be a dual-core variant of Agena shipping in the 2.0 - 2.9GHz range.
Barcelona will be a success for AMD; the long awaited architectural update to K8 should yield significant performance improvements, especially in current areas of weakness for the K8 (e.g. video encoding). Our review of the Athlon 64 X2 6000+ showed that with aggressive pricing, AMD could come close to offering something competitive to Intel. At current prices, we suspect that Barcelona would be enough to close the gap between AMD and Intel. Chances are that we won't see bargain basement prices on AMD's new cores, but we'd expect that AMD would have to maintain a competitive market.
The real catch here is what happens after Barcelona; as we mentioned before, Intel's current successes were born out of steady but regular evolution of a good starting architecture. With yearly updates to the Pentium M, Intel achieved a snowball effect that proved difficult to stop. It would seem that a similar approach by AMD would be necessary to avoid sticky situations like the one it finds itself in today.
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JustKidding - Friday, March 2, 2007 - link
So what you are saying is that it's not the size of your cache that matters as much as how well you use it.VooDooAddict - Thursday, March 1, 2007 - link
With Cache size differences usually having small impact on performance for Athlon64s, the slight trade off for better yields and margins seems the better choice for AMD here.
Regs - Thursday, March 1, 2007 - link
Where was this article 8 months ago? ;)I agree with Anands closing article that AMD now needs it's own "snowball effect" for the next couple of years. 4-5 years with a sitting target against a giant like Intel prooved to be costly in terms of competivness.
We all saw it coming when Intel developed the first Pentium M. It looks like AMD got the message as well and started the Barcelona project. Maybe AMD learned their lesson.
iwodo - Thursday, March 1, 2007 - link
So bascially all intel 's C2D improvement are made into Barcelona. And apart from Virtualization improvement there are nothing new from AMD that Intel doesn't have?On performance note Barcelona doesn't seem to offer better clock scaling. I.e even if it is 30% faster then its current K8 it will only have slight advantage against C2D clock per clock. Not to mention it is up against Penryn. Although Penryn is nothing much then a few minor tweaks and more cache. It does allow intel to scale higher in clock speed.
And given AMD slow roll out rate, and AMD limited production capacity Barcelona never seem like much of a threat.
The article does not mention anything about FP improvement. Are AMD keeping them secret for now or is that all we are going to see?
Spoelie - Thursday, March 1, 2007 - link
The FP improvement is the SSE improvement, and according to the theory it's more powerful than what core2 duo is offering.There are improvements mentioned that are not in core2 (+ other way around, like instruction fusing), and improvements that are inspired on the same principle but implemented differently. The architectures themselves differ widely (see earlier article that compares K8 with Core2 - reservation station etc.) so different implementations of principally the same optimizations on a different architecture will have vastly different effects. Even after these improvements, the capabilities (how much can you decode, etc) of each read nothing alike. And if it were all the same, AMD has the platform advantage, so it would still end up faster by virtue of nothing else but that. Some guesstimates made by varying sites would put Barcelona ahead in FP code and at the same level or slightly behind in INT code. But those are just guesstimates.
What I'm trying to say here is that barcelona is still very different from core2, and that we just don't know yet in which direction the pendulum will swing ;)
Shintai - Thursday, March 1, 2007 - link
No....precisely in theory is where Barcelona lacks. Core 2 Duo could in theory do 6 64bit or 3 128bit SSE instructions per cycle. Barcelona can do 4 64bit or 2 128bit. AMD provided this information aswell.Griswold - Thursday, March 1, 2007 - link
Wishful thinking.Spoelie - Thursday, March 1, 2007 - link
Hmmm, in the earlier article, there was explicit emphasis on the fact that 2 of the 3 units are symmetric in core2, but I'm not too sure what it means. It does imply however that those 3 units of core2 can only be used fully in certain combinations, and are not 3 independent units. On 128-bit performance, what was said is this: "so the Core architecture has essentially at least 2 times the processing power here [compared to K8]". Not 3 times, but "at least" 2 times, so again the 3 times will probably only be in certain situations.The next paragraph said this:
"With 64-bit FP, Core can do 4 Double Precision FP calculations per cycle, while the *Athlon64* can do 3."
So K8 was not at such a big disadvantage when it came to 64-bit SSE, if Barcelona doubles everything SSE, it should come ahead in this area.
So to me it looks like for 128-bit, core2 will be faster in some situations, on par in others, and for 64-bit, Barcelona would be ahead.
If this is wrong, I do not know where some of the articles I read over time came from, implying Barcelona would be better overall in SSE.
Shintai - Friday, March 2, 2007 - link
Core 2 got 3 individual SSE ports:http://www.realworldtech.com/page.cfm?ArticleID=RW...">http://www.realworldtech.com/page.cfm?ArticleID=RW...
AMD says 4 double:
http://www.anandtech.com/showdoc.aspx?i=2768&p...">http://www.anandtech.com/showdoc.aspx?i=2768&p...
And 64 or 128bit doesnt matter. I dont know how you think that way.
Barcelona got 2 SSE ports. They are able to do 2 128bit or 4 64bit. Most 128bit actually contains 2 64bit or 4 32bit.
Core 2 got 3 SSE ports. They are able to do 3 128bit or 6 64bit.
flyck - Friday, March 2, 2007 - link
core duo has 3 SSE units but they are not symmetric, meaning that not every unit can execute all commands. Core duo can do at best 4DP flops/ cycle. the same as barcelona.