In defence of multi-core

Late into this thread but just wanted to echo how totally awesome multi-core is. i've seen a really massive benefit in productivity and responsiveness since moving to dual core a few months ago. I've got a huge desktop res and so I tend to have a lot open (and need it).

Right now I have two copies of firefox open, 1x Word, 1x Excel, 2x PuTTY, 2x WinSCP, Thunderbird, Zend's rather hefty PHP IDE, MSNM, iTunes and MIRC all on the go with zero slowdown - and odds and sods such as explorer windows and a few copies of notepad, calculator... etc.
2GB of RAM probably helps and my desktop res does promote having crazy amounts of programs open and in use... and yes, I am using each and every one of those apps right now except the 2nd firefox which got lost behind a tonne of stuff :D

Quad core and beyond can only get better... :)

Originally Posted by RTT
Late into this thread but just wanted to echo how totally awesome multi-core is. i've seen a really massive benefit in productivity and responsiveness since moving to dual core a few months ago. I've got a huge desktop res and so I tend to have a lot open (and need it).

Right now I have two copies of firefox open, 1x Word, 1x Excel, 2x PuTTY, 2x WinSCP, Thunderbird, Zend's rather hefty PHP IDE, MSNM, iTunes and MIRC all on the go with zero slowdown - and odds and sods such as explorer windows and a few copies of notepad, calculator... etc.
2GB of RAM probably helps and my desktop res does promote having crazy amounts of programs open and in use... and yes, I am using each and every one of those apps right now except the 2nd firefox which got lost behind a tonne of stuff :D

Quad core and beyond can only get better... :)

well said that man!

Originally Posted by aggies11
I could be wrong on this one, (although I dont' think I am, heh), but given the same architecture, a 2xclockrate increase by definition means a 2x increase in speed(instruction completion rate)? (Edit: Upon further reflection the issue of Clockspeed vs performance is really a minor point. I use GHz as simple a simple way to gauge single-core performance. So if it doesn't scale linearly, I just mean performance, not specifically the clock-rate. So you could say "a dual core chip is not equal to a twice-as-fast single core chip". The GHz numbers make the math alot simpler to follow though :) ) I still think the point itself holds though

I'm not talking about GHz ratings in general (how AMD is slower than Intel, and the new conroes are clocked lower than AMD but are faster), just how they are a good (literal) performance indicator between relative members of the same architecture.

I would agree about diminishing returns though, as it becomes harder (takes more $$$) and harder to get faster and faster. It's not the performance that diminishes relative to Mhz though, it's the performance increases that diminish relative to money/time (R&D) spent creating it. Which is why I mention the little caveat how multi-core is essentially unnavoidable/moores law thing.

It has been a while since my CPU architecture course, so I could be totally out to lunch on this one ;), but unless I'm missing something obvious I'm pretty sure this is the case?

Aggies

But if you give 2x as many MHz you've still got the rest of the subsystem to keep up with it. If you run a game at 1GHz and at 2GHz you dont suddenly get twice as many MHz because of the law of diminishing returns. If you give two cores two threads to crunch they will do it just as fast. It's like: Multicore enables you to do MORE at once by offering free resources. The whole point of a PC is not to have everything loaded and waiting all the time. Games and some software will become more multithreaded in order to use it but for those that dont require it it still allows you to do MORE simultainiously, which is the most important thing. Regardless of how crap windows management is, if you ask anyone to compare using a faster single core to a slower dual core chip, most will choose the dual core because it'll offer a smoother computing experience. Also, the reason why they've gone multicore is beacuse they've hit a GHz headroom between 3 and 4 in the consumer environment. It's not cost effective to put two of your product on one die, that's all it comes down to.

i think that the real problem is power.
U can't have a PC with SLI quadcore and use a 500W... at least is what i can't do i have 3KWatt in my home... but the real big problem is an other.. what big LAN parties? If every PC will consume as 2 actual PC...
The technology progress should try to resolve this problem, not find the way to render more polys as possible or to make realistic granade smoke and other junkies. As i can see the only things that they are doing with multicores are grafics effects, and some better AI. I mean OK for the AI but grafic... there's no need of better grafic, we need better games.

Originally Posted by RTT
Late into this thread but just wanted to echo how totally awesome multi-core is. i've seen a really massive benefit in productivity and responsiveness since moving to dual core a few months ago. I've got a huge desktop res and so I tend to have a lot open (and need it).

Right now I have two copies of firefox open, 1x Word, 1x Excel, 2x PuTTY, 2x WinSCP, Thunderbird, Zend's rather hefty PHP IDE, MSNM, iTunes and MIRC all on the go with zero slowdown - and odds and sods such as explorer windows and a few copies of notepad, calculator... etc.
2GB of RAM probably helps and my desktop res does promote having crazy amounts of programs open and in use... and yes, I am using each and every one of those apps right now except the 2nd firefox which got lost behind a tonne of stuff :D

Quad core and beyond can only get better... :)

Not to be an a** ...but at home, I went from a PIV 3.4Ghz to an Athlon X2 4200...and I didn't really notice much improvement when multitasking. And right now, at work, I'm using an old PIV 2.6Ghz with 1 GiG ram, and having open Firefox (4 tabs), Oracle Forms Developer, 2 instances of TOAD with running processes, UltraEdit, Explorer, Outlook and MS Access, I notice no slowdowns...

Is dual core overstated or was just Intel's HyperThreading THAT good? Perhaps those coming from single core Athlons noticed a much bigger improvement?

IIRC, Rich moved from a P4 3.06 with HT. :)

Originally Posted by Tim S
IIRC, Rich moved from a P4 3.06 with HT. :)

From a P4 to Kentsfield? Then that's from 2 logical cores to 4 physical ones. I can see the improvement...

And perhaps I'm no such a heavy multitasker myself, but I noticed more going from 1 to 2 Gb RAM, than going from P4 to X2. Am I the only one?

Yeah, the X2 is smooth, but the P4 was smooth too. Both seem to choke at the same time. Ripping DVDs is noticeable faster with the X2...but other than that, in a blind test I don't think I'd be able to guess one from the other...save from the heat coming from the case, of course ;)

Well I haven't had a chance to use a multicore system yet (other than with servers) but I've have dualie boxes before at work and at times HT. For me it is a huge benefit as I will tend to have a vast stack of applications open and the Dual boxes tended to be much less likely to lock up waiting for one process to finish. Hardly ever was I using a multitreaded application but merely lots of single threaded apps.

The one case where dual cpus, HT and dual core has no benefit is in running a single threaded application in isolation. Which rarely happens except for benchmarking and gaming on a stripped down machine. Of course on a forum like this those two activities are rather more common than in the outside world. Personally I don't go off killing processes and shutting down everything in the system tray before I launch a game so I would get a benefit form dual core even for that.

In work I will have a pile of apps ruining at once. Typically a few access, mail, excel, ie-(again often a few) work, Query Analyser, mmc, antivirus etc, etc. Even a less techie user may well have Word outlook and IE at once, all of which like some resources and will benefit fare more from additional cores than increased core speed.

You should beware of being lead by benchmarks. I remember a few years back people insisting that FAT was better than NTFS based on benchmark times, but ignoring that a few weeks later the FAT drive would be screwed up, showing errors and in desperate need of a defrag.

Just as an aside, and related to the power consumption discussion above, DailyTech already has some numbers on G80 performance here http://www.dailytech.com/article.aspx?newsid=4812

I found interesting that a system with a Intel QX6700 (that's Kentsfield, right?), a WD Raptor and a GeForce 8800GTX, under load, draws no more than 321 Watts (as a comparation, the same system with a x1950XTX, at load, draws 308).

I don't know if this numbers are accurate* but if they are so, it seems threre's little to worry...the highest performing and most consuming CPU + GPU combos can still work with a good 400w PSU

*...shouldn't we know tomorrow Tim??? :D

Originally Posted by Iago
Just as an aside, and related to the power consumption discussion above, DailyTech already has some numbers on G80 performance here http://www.dailytech.com/article.aspx?newsid=4812

I found interesting that a system with a Intel QX6700 (that's Kentsfield, right?), a WD Raptor and a GeForce 8800GTX, under load, draws no more than 321 Watts (as a comparation, the same system with a x1950XTX, at load, draws 308).

I don't know if this numbers are accurate* but if they are so, it seems threre's little to worry...the highest performing and most consuming CPU + GPU combos can still work with a good 400w PSU

*...shouldn't we know tomorrow Tim??? :D

So I can cancell the order for the 3-phase power line and 10KW PSU?
:p

Originally Posted by Risky
So I can cancell the order for the 3-phase power line and 10KW PSU?
:p

You can always get a SATA microwave or something...

Or use a SONY Bravia 50' as LCD monitoring screen...

A couple things to mention here, I've seen them mentioned in the previous pages, I just want to reiterate them and put them in one place.
Multiple cores are not new, and the topic that covers multithreaded programming is concurrency.

The problems are that, despite being given multiple opportunities to start looking at multitreaded programming for the masses, the industry has avoided the subject. Remember the dual core Celeron hack? There was a golden opportunity there. Much of the same discussion from that is being reiterated here. The difference is now we don't have too much of a choise.

There is simply too much to be said here, like where are the compilers to do all the tread work for me so I don't have to do it (the next evolution in optimising compilers)? What are the practical limits to thread level parallelism like instruction level parallelism before it?

In the end, the industry will learn to deal with it because it will be shoved down its throat. Not that I'm saying it'll taste bad, but it is like making fancy patries from scratch instead of simple premixed cookies. Both are tasty, one just takes a whole lot more work.

Originally Posted by Splynncryth
... In the end, the industry will learn to deal with it because it will be shoved down its throat. Not that I'm saying it'll taste bad, but it is like making fancy Patrice from scratch instead of simple premixed cookies. Both are tasty, one just takes a whole lot more work.

Yes! That's exactly it, the games industry is suddenly being asked to make baclava, where as it had previously only been required to bake the kind of pastries that come in a can.

Now if only we can get them to concentrate game play and story, rather than "realistic" graphics... not that this is likely to happen any time soon. . . :(

Originally Posted by Splynncryth

The problems are that, despite being given multiple opportunities to start looking at multitreaded programming for the masses, the industry has avoided the subject.

Again the point is that you don't need a multithreaded app to benefit from dual-core. You just need more than one app needing to do some work at the same time.

Wow fantastic article,

Kind of feel let down by Intel with the kentsfield, they sure let the brainys out on that one!