AMD Finally Unveils Barcelona Chip

Justin Oblehelm writes "AMD has finally unveiled its first set of quad-core processors, three months after its original launch date due to its "complicated" design. Barcelona comes in three categories: high-performance, standard-performance and energy-efficient server models, but only the standard (up to 2.0 GHz) and energy-efficient (up to 1.9 GHz) categories will be available at launch. The high-performance Opterons, together with higher frequencies of the standard and energy-efficient chips, are expected in the out in the fourth quarter of this year. But it's far from clear that this is the product that will help right AMD's ship."

how well will it overclock?

Since it's essentially the same tech since their X2 design?

I get 2.7ghz out of a 2.0ghz rated X2 (on air).

Once again they have beaten Intel's prices by at least $100 so we all win.

Re:how well will it overclock?

Barcelona is a different architecture from K8 (the architecture of the current X2s). It's overclocking performance is currently unknown. Just as Intel's overclocking potential improved as it went from Pentium -> Core 2 Duo, Barcelona may increase or decrease AMD's overclocking potential.

Benchmarks

Here's some benchmarking done by Anandtech [anandtech.com].

And a performance preview for Barcelona desktop as well [anandtech.com].

Re:Benchmarks

Most of benchmarks are on 32-bit code. Can we at least start considering that as "legacy" and use AMD64 when performance really matters?

Re:Benchmarks

Since Barcelona is one of the bigger architectural changes from AMD in the past few years, the 32-bit benchmarks are relevant because they are good predictors of what's to come for the entire product line, including the desktop processors, where 32-bit code dominates. Also, if they used exclusively 64-bit code, they would be accused of using unrealistic benchmarks to highlight the fact that AMD has better 64-bit performance than Intel.

Re:Benchmarks

It could be argued, however, that these are server and workstation chips and so would be expected to perform mainly 64bit tasks to get the full use out of the performance. So 64bit benchmarks would make more sense. Now when the Phenom chips are out then 32 and 64 bits would be both useful as over the next few years most software will convert to 64bit and drop 32bit.

Re:Clock for clock Barcelona is faster than Clover

specfp rate was running faster on pre-barcelona dual core Opterons than on Intel's dual core Woodcrest. The reason is no big secret: specfp is memory bandwidth limited and specfp_rate is specfp's running in parallel. Here is a good anandtech article [anandtech.com] on the subject.

We already know that AMD has superior memory performance. If you are doing bandwidth-limited floating point, Barcelona is the clear winner.

If you're making a general statement about floating point performance, you're wrong.

Re:Clock for clock Barcelona is faster than Clover

I simply want to use the chip that gives me the greatest floating point throughput I can get.

Define throughput. At some point you need to decide if you are solving equations like LinPack or equations like spec_fp. One causes lots of cache misses and benefits from memory bandwidth, the other does not.

Right now that chip appears to be Barcelona.

Well that's a hypothetical statement based on perception of your needs and their marketing.

I'm not interested with hypothetical arguments

That explains why you're making them (???)

I am looking forward to using Barcelona processors because they will get my mathematical computations done faster.

Hypothetically. Are you going to hypothetically switch when Intel's Penryn with SSE4 comes out? What about Intel's Nehalem?

By the way, check out number 2 and 3 on your top 500 supercomputer list - they're Opterons.

And?? They were designed and built before Core 2 was released. Do you think I'm going to argue they should have used Pentium 4's? Those systems also make solid use of NUMA through a custom Cray crossbar (Seastar), and Intel doesn't have that. If they made them today I see no reason for them not to use Opterons. Do you have a computer with lots of Opterons and a Cray Seastar router on order?

The performance of those systems is measured using LinPack. As I mentioned at the beginning, declaring a 2.0 GHz Barcelona as having faster fp throughput than 3.2 GHz Core 2 depends wholly on which types of calculations you are doing. spec_fp does calculations that are memory bound, LinPack does not (at least not as much). Barcelona's faster fp throughput is not due to markedly superior fp unit (though it may be marginally better) but its onboard memory controller. If you need that sort of thing, great, go with barcelona. If you need raw speed on smaller units (under a couple of megabytes) chances are good that the higher clocked Core 2 with huge cache will win.

"Full generation behind"?

"The delay puts the chip maker a full generation behind its archrival in terms of chip manufacturing processes. Intel's quad-core processor, which was launched in November last year, melds two of its duo-core processors into a single package."

Heh, shouldn't that be "full generation ahead" since AMD manages to put four cores on a single die?

Re:"Full generation behind"?

This is a direct reference to 65nm vs. 45nm geometry. If AMD brings their quad core to a 45nm process, that should help yield, power and performance. If nothing else, it puts them on a level playing field with Intel (who already have product at 45nm [intel.com]) so that it's down to "design vs. design." Being stuck one silicon technology generation back, they need to resort to other tricks to "keep up."

In other words, to be at overall performance parity with Intel, they have to have a more advanced design in 65nm to keep up with Intel's 45nm work.

Another thing worth noting: By being 1 generation back, the quad core setup is a double whammy. The die area of a given chip roughly halves with each technology node. Not only is AMD putting twice as much on one chip, it's also making chips that are twice the size per transistor. (Remember, to double square area, you only increase your linear feature size by sqrt(2). 65/45 = 1.444... which is about sqrt(2).) Each additional sq mm of die area causes greater yield loss than the one before it (driven by defect density in the source silicon). Doubling die size has a huge impact on yield. So, AMD will potentially suffer significantly higher yield loss, and correspondingly higher costs. Even if it can keep its ASP (average selling price) up, the profit margins will suck.

It'll be interesting to see if AMD can quickly shrink this design to 45nm and get closer to parity. The benefits of the quad core design probably become much more apparent at 45nm.

--Joe

Re:"Full generation behind"?

That could help with leakage power, but that doesn't address the yield and cost issues at all.

Techreport

The Techreport also has a review up: http://techreport.com/articles.x/13176/1 [techreport.com]. Barcelona is similar to Core2, clock for clock. It has better energy efficiency and SMP scaling. But the clock frequencies will need to come up in order to beat Intel's highest clocking chips in absolute performance.

I'm curious

I wonder how much these things will go for... I know they won't be cheap (in traditional terms), but since AMD has a history of comperable performance for less, I'm really curious how affordable these things will be. If the price is right, one of these may be in my near future...

One thing of note is that Motherboards already exist for this processor in fair number. The Barcelona uses a socket F (1207) which the current dual core Operons already use. That should give this processor a decent jumpstart in terms of people not needing to buy a new board to run it.

Finally, (more) fair wattage numbers!

AMD says it won't use the ACP number to compare the power consumption of its processors against Intel's.

Before everyone slams them for coming up with yet another cheesy marketing gimmick, I would point out that Intel has done this ever since the first of the power-sucking P4 line. They did it a bit less up-front, however, choosing to redefine "TDP" in their specs rather than give their numbers a new term (such as "ACP").

This still won't make for a completely fair direct comparison, because Intel's TDP refers to a sort of third quartile case rather than the mean. But better, anyway.

Perhaps more usefully, since AMD has published the ACP spec, even though they may refuse to run similar tests on Intel chips, you can bet the farm that 3rd-party results will come out over the next few days.

"right AMD's Ship" ?

I don't understand why everyone always talks about AMD's problems. So what if they are not the forunners on every front. They still lead in other areas. Example from July's Inquirer http://www.theinquirer.net/default.aspx?article=41 138&rfp=dta/ [theinquirer.net]

Re:"right AMD's Ship" ?

I don't understand why everyone always talks about AMD's problems.

Because it doesn't matter how many fronts you are leading on, if you run out of money and can't borrow any more, you lose.

AMD has been running out of money, fortunately they can still borrow. If they don't stop losing money their credit rating will tank and then they will not be able to borrow any more.

THAT is what righting the ship means.

Cool

Literally. I can't wait to get in our first DL585 G2 with 4 of these beasties and 64GB of ram. The only regret I have is that we probably won't use em for DB servers because of Oracle's asinine policy of charging per core, sometimes I wish we had gone SQL2005 for more stuff as it is going to scale better with improving hardware. Then again maybe the proliferation of quad core (and above) server cpu's will make Oracle rethink their pricing policy again. I hope they go to what the rest of the industry is doing and license per socket.

Re:If you considered using MSSQL

Uh, MSSQL 2005 is a serious enterprise DB, this isn't SQL 7 anymore. Also none of our enterprise software supports PostgreSQL so invalidating our 6 or 7 figure support contracts just isn't an option even if it WOULD work.

The penalty of moving too fast...

Is that sometimes, you wind up losing the race. I think AMD tried to take a risky approach of putting all four cores on one die and they shot themselves in the foot. Now Intel got some sort of quad core out there. Even if it wasn't as good, it was still better than two completely separate 2 way chips, and now, Intel is circling the wagons to do its own native quad core implementation.

I fear that Barcelona might well wind up as the Great Eastern [wikipedia.org] of chip making - an impressive technological first, but, too much at once. It's a shame too, as I really, really, love my Opteron line, and I know that I will yet again ruin my career writing some sort of multithreaded thing for Barcelona because it is so novel, even if AMD gets battered by a less than spectacular launch.

question for the local geniuses...

If this chip has four cores, how much faster does this actually make something happen? Doesn't the software have to be optimised for multiprocessors? If someone could 'splain this, it would be a public service.

Cheers.

RS

Re:question for the local geniuses...

It depends on three things:
1: Whether the software CAN use multiple cores.
2: How efficiently it uses the extra cores.
3: Whether the program is currently limited by cpu power or by something else.

For "1:", if the program can't use the extra cores, then you'll only see a speed improvement from the fact that the cores are 15% more efficient. i.e. A 2GHz one of these quads performs the same as a 2.3GHz (+15%) dual core from the previous generation for applications in this category.

For "2:", if the program can use the extra cores, but not as efficiently as the first, then you'll see a speed increase equivalent to this. e.g., if the program does two tasks at once, one that takes 70 seconds and one that takes 30, then on one core it'll take 100 seconds. On two cores it would do the 70 second task on one core and the 30 second task on the other, reducing the total time to 70 seconds, a ~40% speed improvement.

For "3:", if the application is limited by something other than the cpu, e.g. "how quickly it can pull data from the hard-disk", you will likely see no improvement whatsoever.

In conclusion, depending on what applications you use, you will see anywhere from no improvement up to 2.3x the previous speed (x2 for double the cores and +15% from the improved efficiency).

Note: As these cpus also have an extra instruction set extension, applications that make use of this could exceed the speed improvements I noted above.

Re:question for the local geniuses...

Doesn't the software have to be optimised for multiprocessors?

Well, it has to be multithreaded [google.com]. Thing is, a lot of software is multithreaded already; even on a single-core system, it makes sense to distribute functionality among multiple threads so that resources are used efficiently. On server systems (which is where Opterons are mostly used) software pretty much has to be multithreaded — you don't want all your other clients hanging when one client is waiting on a resource. A web server is a classic example.

When you move a multithreaded program to a system with more cores, than any given thread is more likely to get a core to run on when it needs it. Assuming, of course, that you have enough threads so that's an issue.

Shameless plug: I'm the docs lead for this Opeteron-based server [sun.com], which can have up to 8 CPUs, for a total of 16 cores. When the Barcelona-based CPU modules are ready, customers will be able to upgrade their systems to a maximum of 32 cores. (Don't ask me when this will happen; Marketing would have me killed.) Obviously any software running on such a system has already dealt with the multicore optimization issue.

Not another fake number AMD!

But AMD customers who relied on the company's previous power metric of TDP (thermal design power) were putting too many resources into cooling and electrical supply, said Bruce Shaw, director of server and workstation marketing for AMD. That's because TDP was developed so server manufacturers would know much power the chip consumes in worst-case maximum-power situations that very rarely occur, and design their systems accordingly, he said. So now AMD will advise customers of an Opteron processor's average CPU (central processing unit) power, or ACP. "ACP is meant to be the best real-world end-user estimate of what they are likely to see from the power consumption on the processor," Shaw said.

Oh Great, first they used the + speed numbers (which I think cyrix actually started but they jumped right in there). I can see that the core speed really meant nothing so I was OK with that, but TDP is a real number. Obviously their marketing folks decided it drew too much power so they opted to make up a lower power usage number. Frankly even a home user wants to know top power usage of the cpu and video card to properly size their power supply.

Re:Not another fake number AMD!

Uh, they are doing this to come closer to Intel's TDP numbers which have been average high use numbers instead of worst case for at least the last couple generation of chips. AMD is actually being much more upfront here by offering both worst case and average case numbers, I hope Intel follows their lead and offers both numbers.

Re:Not another fake number AMD!

Ah, my bad, thanks for clearing this up...so that explains Intels ability to suddenly have lower power chips...so it is they that are playing with the numbers this time, interesting :)

To some extent. The Pentium 4 is where this started. The Netburst architecture was very power hungry normally, but it's maximum power was insane. The graph of power consumption vs benchmark had a long "tail", which Intel sought to chop off. See, TDP is a real-life number, since it's used by OEMs and others to design thermal solutions for the parts. If the thermal solution is insufficient, then the parts fail. So it's not actually possible to fudge TDP numbers.

What Intel decided to do was implement an on-chip thermal diode and some logic that halved the effective clock cycle* if the temperature went above a certain threshold. What this meant is that based on how they programmed this logic, they could guarantee that the chip's power consumption would never go above a certain level no matter what code you were running. They had effectively lopped off the long tail. The downside is that if your application does draw more power than the limit, then you'll see vastly reduced performance because of the clock throttling. Most of the time this is transient so it's not that noticeable, but there were benchmarks out there that showed this effect very clearly. Like a certain game benchmark would get lower scores at 640x480 than 1600x1200 because at the lower res the game was cpu bound as was crossing the thermal threshold.

So theoretically with this feature Intel could fudge the numbers however they wanted and claim whatever TDP they desired. In practice they don't have that much flexibility because if they set the bar too low then their effective performance would suck, and their TDP numbers are set at average power + several standard deviations.

The main reason why Intel was able to suddenly have low power chips is because they ditched the Netburst architecture and went back to a design that was more balanced between high clock speeds and high IPC.

They kept the clock throttling logic, though, since it does still give them some benefit in reporting lower TDP numbers. AMD doesn't have this feature, so their TDP is truly the maximum power (as determined by running a "power virus") that you would ever see, even though it's unlikely. Since power has become ever more important as a marketing feature even outside of mobile, I'm not surprised that AMD would decide to start touting expected numbers vs maximum.

* Actually a 50% duty cycle of full speed for some number of microseconds followed by completely off.

I've been buying Intel/Nvidia . . .

For a few years now, as that was the only platform that really, reliably ran Linux.

Intel's been good to us Linux folk, and Nvidia has been easy enough to deal with.

If AMD comes out with an end-to-end Linux solution, CPU, GPU, and a good Linux-friendly partner for chipset, I'll seriously consider switching back to AMD parts.

Re:I've been buying Intel/Nvidia . . .

Interesting....I've been buying AMD/NVidia for a few years now for the exact same reason....

AMD also has more energy-efficient chipsets with..

AMD also has more energy-efficient chipsets with ECC DDR2 ram not the higher power useing FB-DIMMS also you have a lot more choice in chip set's with more pci-e lanes then intel 2p+ systems.

More Barcelona

Specs of the entire new Barcelons line-up, more details, and pricing are available here as well:

http://www.hothardware.com/Articles/AMD_Barcelona_Architecture_Launch_Native_QuadCore [hothardware.com]

does Intel need AMD

I have owned a PC since early 95 and primarily for financial reasons and then because the Athlon range were, in my option, the best processors available I had not owned an Intel CPU for 12 years. Now for the first time I have an Intel chip, a Dual Core 2 Duo, in my laptop as AMD just can't compete on price or performance. My new desktop will have an Intel Quad core as Barcelona can barely compete with the 65nm chips and the new 45nm chips will just blow it away. Although Intel has it's fingers in many pies not just X86 doesn't Intel need a stronger AMD to stop the government getting involved in trying to limit it's activities to maintain competition?

Blah

What can I say? I'm disappointed that they stuck with a 3-issue architecture - while it is true that Intel's 4-issue setup is often data-starved, even with exceptional I/O performance AMD can only hope to match the Core platform in most situations. The lack of progress in their cache technology means AMD gets as much burden as benefit out of the L3 cache over 20ns access time!).

In the I/O arena, AMD potentially has the edge, and for HPC there's no question Barcelona will do well: this architecture is built for scaling beyond 8 cores (potentially as high as 8 sockets, 32 cores). The question is: how big is that market, and will it really pay-off for them?

In the meantime, small-scale servers and workstations are the majority of the market, and Intel still has a commanding lead in that space. Intel's introduction of the San Clemente Xeon chipset with DDR2 instead of FBDIMMs [theinquirer.net] will not help things for AMD, because these systems can most certainly compete with AMD's low power consumption.

Re:Hey douche...

The use glue? What. sort. of. glue?