Icrontic » Dual Core Processing: Over-simplified, demystified and explained.

^Ben

Mr Ben

9 Sep '04, 9:58 am

gimme gimme gimme

Unregistered

Guest

9 Sep '04, 11:13 am

MediaMan, i would like to give my most sincere thanks for an absolutely fantastic article. Me and a few of my friends here at Shell ( UK ) are really interested in the upcoming dual core technology. The difference between you and other reviewers is that you explained things so smoothly.

Many thanks.

James.

TheBaron

Veteran Icrontian

9 Sep '04, 11:29 am

I love the gimme icon

MediaMan

Driven by Socket 462754939940

9 Sep '04, 11:47 am

James,

Thank you for the comment. I hope you keep poking about our site.

Interpreting the crystal ball on this technology is one part science and one part darts. My crystal ball sees dual core as indeed a performance increase. That's a given with any new processor product at the top of its line.

When you look at it from a consumer cost point of view it begins to make a bit of sense. It's ideal for workstation users who have a desire for a bit more "horsepower" than a single processor system but don't have/want to spend more $ for a dual processor system.

Dual core brings some of the benefits of a dual processor system at less than the cost of a 2P system with the two of the same processor equivalents.

Remember that it's not so much about flat out dragstrip speed anymore. A dragster isn't much good at towing your boat down the highway. It's more about having that big truck with the towing power...that can keep up with the dragster or at least give it a good run for its money.

For server environments it's the same way of thinking. Many run dual processor servers but would really like a 4P server to really go to town. But then there's that cost factor. A dual core system can bump them up between a 2P and 4P system for some aspects of performance (increased multitasking) but without that cost.

For those with oodles of money? Imagine a 4P or an 8P system with dual core processors...that would translate up to a psuedo 8P or 16P system. Interesting if anyone tries to make an 8P dual core system actually work...just for the heck of it.

Bottom line dual core isn't exactly the same as a two physical processor system but it's better at some things than a single processor system. On launch this is more a product for working rather than playing...

In time...it'll become more affordable for us enthusiasts then we'll play too!

QCH

Guru

9 Sep '04, 12:04 pm

WOW MediaMan... Great article. Clear and very well written.

MediaMan

Driven by Socket 462754939940

9 Sep '04, 9:28 pm

Thank you.

Unregistered

Guest

10 Sep '04, 6:07 am

Good article, but one thing: In AMD's Dual Core implementation the cores are NOT linked together using HyperTransport. They uses a more direct coupling called SRQ (System Request Queue). The advantage is that cache coherencey updates between the cores are much faster. I.e. AMD's dual core implementation is no different to it's single core cousin with respect to HyperTransport/crossbar/memory-controller. Of course Hypertransport-Links can be used to extend the system with further CPUs, but that is a differnent story.

Unregistered

Guest

10 Sep '04, 10:24 am

Good article! The best is that it explains things in a way that you don't need to be an engineer or a mathematic professor to understand most of it
I usually understand most of more advanced articles, but why make it more complicated then necesary?

I wouldn't be to suprised if AMD releases dualcore versions of their Opteron 1XX, Opteron 2XX and Opteron 8XX CPU,s in 2005 and not just for the heck of it. A system with 8 dualcore Opteron 8XX CPU's would ofcourse be 16 cores in total.

But I don't think Socket940 will be big in the enthusiast market. Sure some will ofcourse get it, just like there are allready some enthusiasts that have Dual Pentium III/Athlon MP/Xeon/Opteron systems. But I think most enthusiast will get dual core Socket939 Athlons, that probobly will be released in late 2005.
Some may want/need ECC memory and get Socket940 instead or need more then one dualcore processor for the specialized personal use, but I think the Socket939 platform will be more popular.

The one who lives will see.

MediaMan

Driven by Socket 462754939940

10 Sep '04, 2:57 pm

Quoting Unregistered

But I don't think Socket940 will be big in the enthusiast market. Sure some will ofcourse get it, just like there are allready some enthusiasts that have Dual Pentium III/Athlon MP/Xeon/Opteron systems. But I think most enthusiast will get dual core Socket939 Athlons, that probobly will be released in late 2005.
Some may want/need ECC memory and get Socket940 instead or need more then one dualcore processor for the specialized personal use, but I think the Socket939 platform will be more popular.

Funny thing about enthusiasts...we all look for the best deal and sometimes whine about the high cost...but tally up what we actually spend on the entire box. It'll be much more than the average user. We're funny that way.

You are on target that Socket 940 will not be as popular with the enthusiast. Socket 940 wasn't designed for the enthusiast really. Socket 939 is better suited first and foremost because of its ability to use "normal" memory rather than the more expensive REG ECC.

Think of Socket 940 more for the performance workstation. It's a lot of horsepower with the benefits that pertain to ECC REG memory.

By coming out with a BIG impressive Socket 940 FX processor...it grabs the headlines. It says "Hey...look at AMD!". Then AMD can follow up with other products once they have the attention of the readers.

It's the same philosophy as having a loss leader item on sale at a store. The loss leader item brings shoppers in. Very few of them may purchase it but they are in the store...they'll most likely pick up other things while they are there.

Unregistered

Guest

10 Sep '04, 3:44 pm

Funny thing about enthusiasts...we all look for the best deal and sometimes whine about the high cost...but tally up what we actually spend on the entire box. It'll be much more than the average user. We're funny that way.

Yes, it's not getting from A to B that mathers, it's how much fun you had getting there that counts :P
That statement works somewhat better when you look at cars and motorcycles then computers, but computers can be fun to

By coming out with a BIG impressive Socket 940 FX processor...it grabs the headlines. It says "Hey...look at AMD!". Then AMD can follow up with other products once they have the attention of the readers.

Yes, AMD allready do Socket939 version of Athlon 64 FX though. But a Opteron 2XX system will still be nice. If you get that when dualcore gets out that means 4 cores instead, not to shabby

Unregistered

Guest

11 Sep '04, 6:47 pm

MediaMan, great work man.

I've just finished my English homework, we were supposed to find an interesting article and write a summary of it, and of course, I chose this yours.

Keep up the good work.

/SpinBoy

Unregistered

Guest

30 Oct '04, 6:28 pm

I think you should title your page, AMD Hype.

Thrax

Cad

30 Oct '04, 6:36 pm

Or not, because AMD announced dual-core CPUs first, and that's what the article is based on.

Unregistered

Guest

12 Jan '05, 6:32 pm

Acid-

I believe that this is one of the best non-biased articles I have ever read pertaining to processor technology. Bravo.

ronbo

Icrontic Posting Maniac

15 Jan '05, 1:37 pm

MediaMan, I think you missed your calling. You should have been a school teacher. With a article that well written even the class clowns would get an "A" on their exam....bloody good m8..

Unregistered

Guest

30 Jan '05, 6:36 pm

IBM have had a dual core server chip out for years, so saying that AMD engineers have "cracked" anything is perhaps innaccurate, all they have done is brought the option of a dual core cpu down to the pc level.

mmonnin

Veteran Icrontian

30 Jan '05, 7:11 pm

And thats what matters to us now isnt it.

Unregistered

Guest

6 Feb '05, 3:49 am

I don't understand how an app (e.g. Photoshop) could take advantage of an SMP. I mean, doesn't the OS "shield" the hardware from the apps? Applicantions are not supposed to know about whether it is a uniprocessor, an SMP, or a dual-core, right? And what if the app knows it's SMP or dual-core, but the OS doesn't support SMP or dual core? Is it possible? Thx.

Unregistered

Guest

6 Feb '05, 4:04 am

sorry that i have to make a comment about 64 bit processors here, because there is no 'comment' feature in the "64-bit simplified" article.
What on earth is a 64-bit processor? Does it mean 64-bit data bus? 64-bit control bus? 64-bit registers? 64-bit everything?

Thrax

Cad

6 Feb '05, 4:44 am

I don't understand how an app (e.g. Photoshop) could take advantage of an SMP. I mean, doesn't the OS "shield" the hardware from the apps? Applicantions are not supposed to know about whether it is a uniprocessor, an SMP, or a dual-core, right? And what if the app knows it's SMP or dual-core, but the OS doesn't support SMP or dual core? Is it possible? Thx.

The OS doesn't do any more shielding from apps these days than buffer overflow protection with the NX/EDB bits on Intel/AMD processors. Applications, the OS, and the hardware is designed to let the application know if SMP exists explicitly for the purpose of taking advantage of it. Applications are most certainly supposed to know. Additionally, if the OS doesn't support SMP, the application has no idea -- it's all fed directly from the OS.

sorry that i have to make a comment about 64 bit processors here, because there is no 'comment' feature in the "64-bit simplified" article.
What on earth is a 64-bit processor? Does it mean 64-bit data bus? 64-bit control bus? 64-bit registers? 64-bit everything?

In computers, a 64-bit processor is one in which data is processed and/or stored in 64-bit chunks. The term often refers to the size of the CPU's registers that holds memory adddresses and other data, as well as the arithmetic logic unit that operates on those registers to compute. Busses have been varying widths for ages, with the Athlon XP being a 32 bit CPU with a 64 bit bus (Twin 32 bit pipelines) -- the Athlon 64 has a 64 bit memory-to-CPU bus, and a hypertransport bus which is CPU-to-chipset and it's 16bit bi-directional. A computer architecture described as "64-bit" generally has integer registers that are 64 bits wide and thus directly supports dealing both internally and externally with 64-bit "chunks" of data.

Bus widths don't count in the equation.

Unregistered

Guest

4 Apr '05, 5:50 am

if more info needed i will register

Unregistered

Guest

5 Apr '05, 11:00 pm

Nice article, very informative.

Unregistered

Guest

8 Apr '05, 1:02 pm

gimme gimme gimme !!!
Great article, Thanks!

Unregistered

Guest

2 May '05, 6:26 am

I do have a question ! Will these processers be more ESD sensitive that
the commonly used ?? Will special precautions have to be taken ?
JG

MediaMan

Driven by Socket 462754939940

3 May '05, 1:17 am

For those who may not understand the previous poster's question;

ESD = Electro Static Discharge.

ESD is a term most commonly used when handling/transporting electronic equipment such as microprocessors. I would imagine that the dual core processor would be handled with the same precautions as a single core processor. The ESD risk would be the same.

Unregistered

Guest

29 Jun '05, 4:22 pm

Excellent! Excellent! Excellent!

Guest

8 Jun '06, 11:49 am

Thanks

Sledgehammer70

8 Jun '06, 11:50 am

Wow this came out of the wood works...

Guest

18 Jun '06, 5:54 am

Thank you so much for putting together such a great article. This is the best explanation I ever got about the dual-core technology so far, and, finally, I start to understand how things work.

Guest

21 Jun '06, 4:49 am

thanks man
i learnt a lot!

Guest

24 Jun '06, 12:42 am

thanx

nrwilk

Icrontic Convert

24 Jul '06, 9:09 pm

Awesome breakdown!

Quick question:

I saw some computers advertised on ebay with intel core duo procs. The seller claimed the the Ghz rating applied to each core, making a dual-core 2.0Ghz chip actually clock at a total speed of 4Ghz all together.

Is this anywhere near true? Seems oversimplified to me.

primesuspect

The Icrontic Guy

24 Jul '06, 10:05 pm

It's not true. The cpu still clocks at 2ghz. The seller is using pseudoscientific fakery to make the thing sound better than it is. That is not to say that a dual core 2.0ghz is a slouch. It is a cutting edge machine. The seller should be more honest - that thing could sell itself without relying on that kind of bullcrap.

Britton

Guest

17 Jan '09, 11:39 pm

Yes that is a great article for sure. I just got this laptop and its dual core. An Athlon X64 running at 1.9Ghz and believe me I know what you mean about the heat issue. A 10Ghz processor would probably melt the casing on the laptop. This cpu is only 1.9Ghz but when I play games like Sacred 2: Fallen Angel it makes the case get almost untouchable. I don't have the spare money right now to buy a cooling pad for it. So I just use the small desk fan I have and place it near it at an angle that seems to keep it cool. I guess overclocking it out of the question.

The one thing I am unclear on is: Does the dual cores actually help my programs run faster or is only one of the two cores processing the data for an individual program. Also since each core isn't independently running at 1.9Ghz a piece (making it 2.9ghz over all) then does that mean there only running at 955mhz each?

Komete

DIY Haxx0r

18 Jan '09, 12:08 am

Wow, you just revived a 3 year old thread

If a program is optimized to run on dual cores, than yes your aplication will see a boost. If it isn't, you won't in that one application. However, having dual cores allows you to multitask better and faster because while one cpu is busy running one or two applications the second one is free to run others. It doesn't always work out like that but it is the goal.

Just put it this way, having more than one cpu decreases the likelihood your hole pc has to slow down because it is being maxed out.

And they both are running at 1.9ghz but you bios may throttle cpu speed up and down as needed.

Quoting Britton

Yes that is a great article for sure. I just got this laptop and its dual core. An Athlon X64 running at 1.9Ghz and believe me I know what you mean about the heat issue. A 10Ghz processor would probably melt the casing on the laptop. This cpu is only 1.9Ghz but when I play games like Sacred 2: Fallen Angel it makes the case get almost untouchable. I don't have the spare money right now to buy a cooling pad for it. So I just use the small desk fan I have and place it near it at an angle that seems to keep it cool. I guess overclocking it out of the question.

The one thing I am unclear on is: Does the dual cores actually help my programs run faster or is only one of the two cores processing the data for an individual program. Also since each core isn't independently running at 1.9Ghz a piece (making it 2.9ghz over all) then does that mean there only running at 955mhz each?

CyberKing419

Guest

18 Oct '09, 8:51 pm

which is better and why dual core processor or quad processor?

Thrax

Cad

18 Oct '09, 8:58 pm

Quad. More processing power.

ardichoke

King Banana Spanner

20 Oct '09, 4:33 pm

Debatable. Right now few things utilize quad core processors to the fullest. If you're debating between a quad and dual core running the same speed, yes, get the quad. If you're debating between a slower quad core or one with less cache and a faster dual core or more cache it may be worthwhile to get the faster/more cache dual core processor.

jbe

Guest

8 Nov '09, 1:55 pm

You're leaving out way too much.

First of all, the pipeline is just a cache of scheduled instructions. This means that a long pipeline yields high performance, only when the pipe is full of instructions that are actually usable at time of execution.

It's hard to explain, but I'll give it a try.

While processing instructions, it's important to always have a next instruction ready to execute. Feeding instructions (through the pipeline) to the CPU synchronously, makes it perform at optimal speed.
Some instructions have a clear outcome as to what the next instruction will be. Hence, these instructions are "injected" in the pipe. The instructions in the pipe, are executed immediately after the CPU has finished its current "job" (instruction).
However, lots of instructions are not statically predictable. So, processing architectures use a technique, which is known under many names, let's call it prediction.
When the next instruction to be performed, is predicted correctly, it will be executed without any loss of clock ticks. Hence, in theory, when prediction is 100% correct, every MHz counts as more speed.
Relating this back to the length of the pipeline.
When a prediction is not correct, the complete pipeline is discarded. After all, when an instruction somewhere in the pipe is not relevant anymore, the instructions that follow, aren't either.
So, as you can guess, having a 31 instructions length pipe, will only give great results when prediction is correct. Ultimately, when prediction is 100% correct, every clock tick is optimally used. However, when a prediction is incorrect, the whole pipe has to be discarded. Off course, it has to be filled again as well.

See, for instance, the architecture of the IBM PowerPC G5 (used in the older Macs). A RISC processor with an extremely long pipeline. Anyone who has used one of these, will have noticed how some applications performed incredibly fast and some others just didn't perform at all. It all has to do with the way they were compiled and how predictable the instructions were.

I'm leaving it at this. The only thing I have left to say, is a reaction to the following line.

Now remember that the processor cache is running at the same clock speed as the processor itself.

Only the L1 cache, L2 is slower, L3, even more!

Cheers,
Jan

Dual Core Processing: Over-simplified, demystified and explained.

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