AMD Demos Dual-Core Athlon 64

DigitumDei writes "Dual core chips came closer to reality as AMD demonstrated their Athlon64 dual-core offering. The 90nm technology chip will use the same 939-pin infrastructure and cooling solutions as the current Athlon 64 chips, meaning that upgrading to a dual-core chip from your current AMD64 will require little more than a BIOS update. Available in the second half of this year, the chip will be added to AMD's current line (Athlon64, Athlon FX, Sempron)."

Comments

Am I Missing Something?

[Dragoon412]

I don't understand the hype about dual core CPUs.

As I understand it, they work almost identically to a SMP setup, meaning they don't offer much of any performance benefit in most apps (particularly games). They draw more power, they run at higher temperatures, etc.

Is there something I'm missing? Or is this whole dual-core mess really just SMP on one CPU? Because from what I've read on the likes of Extremetech, Anandtech, and so on, I'm not finding any reason to be impressed.

Re:Am I Missing Something?

[Anonymous Coward]

Well, during games one proc can run the game and one can run the OS...assuming you can dedicate one processor to a process? IANAAMDE.

Re:Am I Missing Something?

[drwtsn32]

Sure, benchmarking a single app on an SMP system often makes little to no performance difference, but SMP is fantastic if you are a heavy multitasker and work with several apps at once.

My first SMP system was a dual Pentium 133Mhz box. After that I never went back to a single proc... until the Pentium 4 came out. It's disappointing that this chip does not support SMP (except for the Xeon line). P4 hyperthreading helped bring back some SMP goodness, but it's still not as good as two real chips.

Personally I can't wait for dual core CPUs!

Re:Am I Missing Something?

[Shalda]

Effectively it's SMP on one CPU. Something I very much look forward to as I always build my desktops SMP. It also incorporates some of the overhead of SMP into the CPU driving down the system price a little bit.

While you're right that SMP offers little performance to most apps, I tend to run a lot of CPU hogs at the same time. Watch a DVD while waiting for a project to finish compiling or whatnot. It can also help keep runaway processes from sabatoging your system. I used to have a program that set its priority to 'AboveNormal' and would from time to time it would hang up in a loop. Since it was running at a higher priority, you sometimes couldn't bring up Task Manager to kill it off as the higher priorty thread always took precedant. And if all else fails, you can set up 2 SETI @ Home clients and process twice as many packets. But do your self a favor and set their priorty to 'Low'.

Also, you've got a chicken and egg problem. The reason there's so few programs that benifit from SMP is that there are so few computers that are SMP. When I was running some computer labs at a Big 10 university a few years back I was insisting on SMP workstations so that the CS students could learn to program multithreaded apps and see the benifits of it when it ran on 1 vs. 2 processors.

Lastly, my basement is very poorly insulated and gets a bit chilly in the winter. Anything to help warm it up and keep my fingers working properly is a good thing(tm)!

Re:Am I Missing Something?

[roach2002]

Some instructions on the x86 hardware have a delay; let's say I'm asking for something from ram or cache. This takes more than one cycle (3 from cache if I remember correctly). On a normal, non hyperthreading processor, the processor sits idle until that memory value comes back.

On a hyperthreading processor, the processor can do an instruction on another process in that time. So a second process can come in and do a couple ADDLs.

It may not make your game run any faster, but if you have something in the background that can complete what it's doing more quickly.

SMP with n processors can theoretically run n instructions in one cycle. Hyperthreading still limits you to one instruction per cycle per processor, but it reduces the number of cycles where the processor does nothing because it's waiting on other hardware.

So for you, it probably isn't worth it. But for some workloads, ie: some servers that are constantly delaying on memory, it can speed secondary processes up

Re:Am I Missing Something?

[oldmanmtn]

As I understand it, they work almost identically to a SMP setup, meaning they don't offer much of any performance benefit in most apps (particularly games).

I suppose if your idea of "most apps" is games, then this probably isn't an area that would be of interest to you

If you have any multithreaded app that is even remotely competently written, then it will benefit from dual cores or (possibly) hyperthreading. If your multithreaded app is full of "big locks", then dual cores won't help, and the application designer is a failure.

If you have a workload that has multiple processes running simultaneously, then it is also likely to benefit from dual core. It gets more interesting with business/server workloads, but "home users" can benefit two. Even something as simple as running xmms and gcc at the same time should go faster. Or running two instances of lame.

The real win with dual core comes from increased throughput. A single job/application/process isn't likely to go any faster, but a full workload of multiple, reasonably parallelizeable, tasks will be faster.

Re:Am I Missing Something?

[c.r.o.c.o]

SMP without the mess (extra CPUs, cooling, expensive/complicated motherboards) and cost is definitely something to be impressed about.

The motherboards supporting dual core CPUs should be identical to those running single core CPUs. I guess this is where having the memory controller integrated into the CPU really pays off for AMD since it further simplifies mb design. But in the past SMP motherboards weren't THAT much more expensive (at the most $100 extra) than similar single CPU motherboards. The main cost associated with SMP setups were the very expensive SMP CPUs, which were anywhere from 1.5 times or more expensive than regular CPUs. The pricing of dual core CPUs remains to be seen, but I think it'll still be cheaper than 2 separate SMP-enabled CPUs.

However I completely agree with the rest of your post. Not having separate heatsinks, large motherboards, etc is a definite advantage. Just because of that the market acceptance will increase very rapidly. I wouldn't be surprised if games and other CPU intensive apps started supporting dual core CPUs soon.

Re:Am I Missing Something?

[Anonymous Coward]

Yes, you are missing something. Many of us use computers for more than games. Java applications for instance are nearly always threaded and benefit greatly from multiple CPUs (at least on Linux, I can't speak for Windows). Or how about working on a PowerPoint presentation while your spread sheet recalc's. Most any app that has a GUI will be more responsive if other activities are going on as well.

Whether the price difference is worth it is another question. Also you can expect many threaded apps to break. If you haven't debugged a threaded app on a multiple CPU system, then you haven't debugged the threaded app. And how many developers have multiple cpu systems laying around?

Re:Am I Missing Something?

[Vaystrem]

I've had the pleasure of using a number of friends Dual CPU systems across the years.

The most relevant one to this discussion is my friends Abit BP6, Dual Celeron, setup. At the time he was running Dual Celeron 300s. Not that impressive right? Except that he was able to host our Unreal Tournament Server - and then join it with no lag for any of the players. Running Unreal Tournament by himself showed a 50% load on each processor. He was able encode MP3s, burn CDs, and play games simultaneously. Something I was not able to do, and wanted to for the sake of time saving. I did not want to choose one activity over another - a 'leisure' productivity issue if you will.

Fast forward to now. A nice dual cpu system would allow me to play games, encode movies / my audio files, simultaneously while running Distributed.net. Are dual core's absolutely necessary? No, but when you are doing some very intensive applications you can't do anything else. As well even though not all games are multi-threaded, various aspects of the game may be, the networking code/the sound code etc, meaning that the game may run somewhat better on a dual cpu setup.

Re:Am I Missing Something?

[Thagg]

Multiprocessing, both discrete and multicore, will accelerate all compute-bound applications in the future. Right now we haven't reached a critical mass yet -- where programmers feel it's worth the effort to multi-thread all of their applications -- but we will get there soon. It's not an easy change, and there are a whole world of problems that programmers haven't had experience with yet, but either these programmers will learn or they will not be competetive any longer.

Face it, the days of increasing clock speeds is over. It's done. Finished. Kaput. The low hanging fruit has all been eaten.

On the other hand, the multiprocessing benefits are huge and practically untapped. There is every reason to expect that in ten years we have 64 or 256 processors on a chip. People who hope to be working in ten years better learn how to write for these systems.

Compare the P4 to the Cell. The P4 goes to unbelievable lengths (even literally, in pipeline lengths!) to run at a high clock speed. Its contribution to global warming is substantial. It's expensive. And, it's an absolute dead end. Intel has already abandoned it.

The Cell has eight much-simpler processors along with its Power core. It can, and will, compute 10 times as fast as a P4, if programmed correctly. The game programmers are going to be pulling their hair out for the next couple of years, but they are going to be the high-demand programmers of the next decade as they are the first over the wall of significant multiprocessing.

Thad Beier

Re:Am I Missing Something?

[Just Some Guy]

But what's the processor utilization? On most systems, its usually less than 10 percent. So when a user does something, the bottleneck is usually not the processor. Its usually the hard drive.

That's most systems, but certainly not all. I wrote a web application in Zope that acts as a portal to our scanned document warehouse. Whenever a customer wants to access some of the data we're storing for them, we fetch a few TIFFs from a Samba filesystem, convert them into a PDF with ImageMagick, and send them out. A RAID wouldn't make a bit of difference to our setup, since even the comparatively slow network file retrieval is much faster than the image processing which is the real bottleneck.

Our system is idle probably 95% of the time. In fact, it currently has a 5-minute load average of 0.04. But in that other 5% of the time, we want it to respond NOW and not 30 seconds from now. This is a pretty common situation for server machines - relatively long periods of inactivity punctuated by short periods of frantic scurrying - and it seems reasonable that AMD is offering their 64-bit server chip with this feature.

Re:Am I Missing Something?

[magarity]

What makes you think the database is CPU-bound instead of I/O-bound?

CPU load versus disk queue length versus memory page accesses. But no worries about my off the cuff example being the only case; a very popular move these days is to run VMware (or similar) on an 8 or 16 way machine in order to provide 20, 30, or more "servers" doing light to modest loads so introducing dual core CPUs will allow even more virtual servers hosted on a single physical box. The cost saving potential is TREMENDOUS.

And what makes you think the manufacturer of the two machines will allow this software patch

It only takes one manufacturer to advertise "Buy our 8 way single core now and upgrade to dual core on the cheap later!". You can buy an 8-way now with only 2 CPUs and add later; there's no reason why you won't be able to buy 8-way dual core capable with only a few single cores and upgrade/add CPUs for years. Big corporate servers costing serious money are upgraded and/or assigned to different roles for a long time compared to desktop PCs. It's a whole different world. One company *finally* decommissioned a quad PPro server and donated to a nonprofit I know. That's been in service 24/7 for what, 14 years? It was probably over $50K when new and they have to get their money's worth out of it. Anyway, the manufacturers know that most IT budgets are not unlimited and customers always like less expensive alternatives.

Re:Am I Missing Something?

[twiddlingbits]

RAID's whole purpose was NOT speed it was REDUNDANCY. Most RAID controllers are just an upgrade over the standard ones in most PCs, that's where the performance upgrade comes in. They move data faster but if your program can't process the data as fast as it comes in you really don't see a benefit. And even with RAID the disk size makes a difference, smaller is better in many cases.

Why not two different clock speeds?

[Gates82]

Rather than using two identical chips, is there any difficulty in putting say a 2.4 Ghz chip with a 500 Mhz one? I would love to have the latest and greatest chip for gaming, and crunching through video and then have a low powered second chip to play my mp3's and surf the web, while the high-end chip is crunching through numbers in the background. Guess that's why I have a laptop, play on that while the desktop is doing its thing.

--
So who is hotter? Ali or Ali's sister?

Re:Why not two different clock speeds?

[bbrack]

While there may be separate clock domains per core, the clock multiplier circuitry may be contained in the arbitration logic, as this could probably improve the arbiter's efficiency.

I think that the design specifics of the arbitration logic (specifically, what speed it communicates with the cores, and how core-to-core communication is handled) is the determining factor in how feasible multi-frequency dual core circuits are.

I'm poor!

[shamowfski]

Does dual core mean dual price? With current fx-55's costing around a grand, what can we expect these to cost? 1,500-2,000? If AMD wants to remain competitive with Intel they are going to have to work on that. Who ever guessed AMD would be the one who had to lower prices to compete??

Awesome! 939 Huzzah!

[Anonymous Coward]

I actually just purchased a socket 939 board for this exact reason. I'm extremely pleased with AMD for not forcing yet another motherboard upgrade on us based on chip advancement. I got a cheap Athlon 64 3000+, but two or three years from now I can go dual-core without getting a new motherboard, memory, etc. and I like that.

I understand that sometimes it's necessary to upgrade motherboards instead of just chips (FSB adn so forth), but for those of us who can't afford top-of-the-line, bleeding-edge stuff, it's nice to see upgradability for more than just a few months into the future.

Free Sony PSP from Gratis

Re:Check your licensing agreements first

[Anonymous Coward]

What's gonna happen when you try to install the Intel Dual Core "Extreme Edition" on a Windows XP box?

XP sees the single core + HT chips as 2 CPUs, but if the extreme edition dual cores are HT enabled, will XP allow "4" CPU's??

Re:How much power is "reasonable"?

[Jugalator]

Now, also, how many OSs (and applications) are prepared for dual-core support?

I won't go into detail of applications since I have no idea which apps you're interested in, but Windows XP Pro supports dual cores (it runs its multi-core kernel even if you just have a Pentium 4 with hyperthreading).

Windows XP Home will not suffice though, which is a bit amusing since this might be the most common OS sitting in homes of gamers which are often the early adopters of this kind of tech nowadays. Unless they just pirated Windows XP Pro with a volume license key of course. :-)

Windows XP Media Center Edition, and Windows XP Tablet PC will support multiple cores though, probably in the same fashion as Pro.

Another one may give details about the common Linux distros, but I'd be very surprised if this support isn't in by far most modern distros, or can be enabled fairly easily.

Re:Check your licensing agreements first

[Jugalator]

That's an interesting question. :-)

First, I think Microsoft has previously said they'll only charge one license per physical processor. However, the problem is that Windows XP Pro supports only 1 or 2 logical CPU's. I wonder how it'll react. It seems like you'd not make optimal use of your system. And in case it does restrict itself upon working on two logical CPU's, you should hope Windows XP restrict itself upon the two cores instead of one of the cores and the HT feature on it!

Complexity

[Efialtis]

They have been expirimenting with multi-layered parallel processing for a long time, and I think this is the "realized results" of those expiriments.
We will see newer dual and multi-core processors come out in the future, and tha ability to parallel process with multiple chips on one board...
Should be exciting...

Sweet...

[sapgau]

Intel wake up!! See how easy it is to upgrade, no new socket layouts, no new motherboards.

Besides trying to determine what model is the Pentium dual core gives me headaches.

/owns AMD, trying very hard to repress fanboy attitudes.

So buy a cheaper processor

[mapmaker]

With current fx-55's costing around a grand, what can we expect these to cost? If AMD wants to remain competitive with Intel they are going to have to work on that.

If you need a car but you're poor, you buy the Chevy Cavalier, not the Chevy Corvette.

If you need a processor but you're poor, you buy an AMD Sempron, not the AMD FX-55.

Complaining that AMD needs to lower the price on their top processors is like complaining that Chevrolet needs to lower the price of Corvettes.

Lockless techniques to the rescue

[bsmoor01]

I think this will be overcome with more atomic instructions from cpu vendors. Lockless techniques generally give much higher performance, and can often acheive the same goals as the old 'lock to enforce synchronization' paradigm you mention.

I use lockless counters heavily in the code I work on in order to reference count objects. Very handy, and much faster than lock-based counters.

The pain with lockless coding is that there aren't many portable primitives. So I have to maintain my own abstractions for every platform I work on, which is a pain since I'm in embedded systems. It would be awesome to have a standard (AND portable) lockless utility library. One day perhaps...

Closer to reality?

[cmclean]

Dual-core chips are already a reality, Sun's UltraSPARC IV uses 2 UltraSPARC-III pipelines.

Perhaps the author means "x86 dual-core chips"?

Re:Dual Processor, Dual Core?

[speculatrix]

there's nothing in the article to suggest that a dual-core amd64 can be used in a dual-cpu motherboard?

I would think that AMD will have to make multi-cpu versions of the dual-core chips, to support the inter-cpu comms, just as there are 1xx, 2xx, 4xx and 8xx versions of the regular opterons. But it'd be cool to cheaply upgrade a dual mobo to quad!

We have some dual-cpu opterons tyan motherboard machines here, and they are awesomely quick - we use FreeBSD, amd64 where possible but too often i386 mode because java and other things aren't supported in 64 bit mode at all yet.

rc5-72 rating is about 9M keys per second, twice that of a P4 2.8GHz machine; however, they are slaughtered by a dual Apple G5 system which achieves nearly FOUR TIMES the performance.

Hope they make cheap ones

[springbox]

I hope that the processor manufactures make some economy version of the dual core CPUs like Intel has done with the Celerons, since anything new coming out from that industry seems to be generally pretty expensive.

Mmm dual core Celeron..

actually there is a differnce....

[kidoman]

i beg to differ,

however, anyone who has compiled [anything] in a SMP (2 way or 4 way) knows that SMP does make a big difference.

therefore dual cores will eliminate that mental bottleneck of having to buy 2 processors and the backwards compatibility is just an awesome gift!!!!