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."

Re:"Full generation behind"?

[Mr Z]

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:Techreport

[tietokone-olmi]

AMD's had I/O performance and memory latency advantages on Intel even before Barcelona though. I suppose Intel will be in even more serious trouble than before in the server space, until it can get its next-generation bus thingy (CSI they called it?) up and running in a year or three. Until then, Intel's stuck in a SMP scaling black hole... and I don't really see Intel coming out with integrated memory controllers and native NUMA like AMD did with their whiz-bang DEC Alpha engineers.

Once Barcelona ramps up, Intel's going to be hard pressed to come up with an advantage besides clock speed for the C2 microarchitecture, given that Barcelona finally ups the SSE units to proper 128-bit wide computation; i.e. none of that splitting of SSE operations into pieces that are executed 2 pairs of operands at a time.

Remember, high-performance floating point is not the mainstream workload that determines the success or failure of a microarchitecture. (Though it is one of the sexier ones.) So no yammering about "absolute performance" there; AMD's previous-gen offerings were crazy fast before the C2D and aren't half bad even after C2D.

Re:how well will it overclock?

[jimstapleton]

Core2 Quad = Desktop

They are talking about server chips, which typically are more expensive than desktop chips.

If you considered using MSSQL

[Anonymous Coward]

If your database requirements are such that you could have use MSSQL instead of Oracle, you really should consider using PostgreSQL, as it is more featureful and costs nothing.

Re:Not another fake number AMD!

[afidel]

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:If you considered using MSSQL

[afidel]

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.

Re:Benchmarks

[ceeam]

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:"Full generation behind"?

[Mr Z]

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

Re:question for the local geniuses...

[fm6]

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.

Re:Benchmarks

[644bd346996]

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:Clock for clock Barcelona is faster than Clover

[Wavicle]

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:haha, oh man, charging per core is a break

[Chandon Seldon]

I've never used it but Oracle is either one hell of a database, or one hell of a brand for people to put up with tactics like that. That shouldn't even be legal.

Oracle is an amazingly powerful brand and managers think that "scalability" is something you buy rather than an engineering problem for programmers and system architects to solve. That's really the whole story. Given what servers cost and the actual performance differences between different database software given appropriately written client software, purchasing Oracle licenses is largely inexcusable unless you have existing Oracle dependent software and no time to switch databases and re-address scaling related design questions.

Re:"right AMD's Ship" ?

[Wavicle]

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.

Re:Benchmarks

[evilbessie]

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.