In defence of multi-core

Field of Dreams

Great article. What I have seen over the last 20 years is very much along the lines of the movie Field of Dreams. If you build they will come. As long as hardware, regardless whether its CPU, VPU, Memory, or Buss architeture, continue to make advances the programmers, users, and system builders will find a way to utilize those advances till they reach the point of needing more.

 

I agree 100% the only time something is not needed is if the performance oustrips demand, this never seems to be a problem with most hardware I mean software will come along to fully take advantage of the multiple cores in the near future. The only issue where I'm on the wall is data storage, it seems areal density of harddrives are going up at a rate that outpaces the needs of consumers, I.E 400+gig hard drives, I'm not saying more space is a bad thing, the only time it coudl be negative is if a HDD gets so cluttered finding that picture you took 3 years ago could be one of 10,000 possible pictures. It's more that I don't think the average user needs 400gigs of HDD space, I spose with the high def content we'll see a bump up in data size but even then the average user won't be needing 500+ up to a terabyte of storage, I'm more concerned about redudancy and speed

my 2 cents

 

Correct me if I'm wrong but part of the problem I see with multi-core at the moment is the Windows process scheduling. This is especially apparent with Intel chips which use the FSB to transfer data between the cores. The problem here is that windows will attempt to run a single thread on both cores by switching cores every 1/50 seconds (or whatever). The result being that that the CPU is constantly using most of the FSB to find data from the cache of the other core that has just been calculated. I have noticed that by setting the affinity of a process through task manager to one core my whole computer speeds up (sometimes quite significantly). I can only imagine that this problem would be worse if there are 4 cores.

However ignoring that problem I think that multi-core CPU's are definitely the way to go at the moment.

 

Errr...no, you don't. I'm sure that the PSU manufacturers would love that we believed that, but it's not true.

A good 350W - 400W PSU can easily power most demanding single GPU gaming systems with little effort. (the almighty X360 draws less than 180W IIRC and it has 3 PowerPC cores and a next gen ATI GPU.)

For dual GPU configurations, you can do with a efficient 600WPSU (I used a Tacens VALEO 420W to power a X2 4200 + 2x7800GT rig and it run perfectly fine...). I bet you could even power it with a 500W, providing it had 85% efficiency or so, and good 24v rails. I agree it's too much, but it's far from 1000W.

This generation (DX10) is going to get ugly regarding power consumption, and still, I very much doubt you'll need anything bigger than 700W...much less for single GPU configurations...and as Tim says, it will get better the generation after this.

 

Perhaps you have never measured your systems power draw but often its not wise to run near peak load on a PSU for prolonged periods, most of the PSU manuals tell you this, suggesting that people will be fine with a PSU on its limit with 'most demanding single GPU gaming systems' (like 350w-400w mentioned) is lunacy, as different computer parts consume different levels of power and you need to spec accordingly, the efficiency part relates to what is pulled from the wall not how good a PSU is at providing power to your system, I have a dual GPU setup (7900s which are more efficent than the old 7800s) with an X2 and peak load when gaming can spike to 630w (measured from wall socket) this is using an FSP epsilon 700w with 85% efficiency putting my system in the region of 535w, the same system but with 7800GTX512s (approx 40w per card extra when OC'ed a touch) blew an OCZ Powerstream SLI jobby that was 520W or something like that which can handle a 630w peak after very little use, people told me it should be fine and its just PSU manufacturers trying to sell kit, a lot of people also said stuff like I run such and such 500W PSU witha similar setup and its fine, all I can say is good luck to you, if you intend to buy any next gen kit you will want to make sure you have the appropriate supporting hardware and a PSU is an important part of this.

 

This article is from the "silent PC" point of view, but still, it's a great read and should help to dismiss many of those PSU myths:
http://www.silentpcreview.com/article28-page1.html

Some relevant quotes from the HOW MUCH POWER IS ENOUGH? section of said article, for those without time to read it (it's quite long).

Here to can calculate expected PSU needs for most systems:
http://www.extreme.outervision.com/psucalculator.jsp

For a gaming system, with a Core 6600 and a 7950 GX2 (quite high end if I may say), 2 SATA HDD, 2 Gb Ram, 1 DVD/DVDRW drive, 4 USB devices and 4 fans, they recommend 345W PSU wattage.

Now, I know that if you overclock heavily, put water cooling, x1900XTX in crossfire and pimp the rig with as many neons as a casino in Las Vegas, you can easily get outrageous power requirements, but that's not the norm, not even on high-end systems. Certainly, someone doing that is likely to be aware of what his power requirements are and if you are getting so much hardware, an extra 50-100€ in PSU wattage is probably irrelevant...but all this talk about 700W PSUs being standard, is an exaggeration. The kind of people, even on "enthusiast" sites that nowadays needs anything over a 500W PSU is very, very rare.

[edit]
My own X2 4200 + 2Gb RAM + 2 HDD + x1900XT... has a recommended PSU watagge of 350W (at 100% Load for the PSU, not average). With 2 7800GT in SLI I get 365W. Hardly earth shattering...

 

I'm building a new conroe-based PC in an Antec P180 - I tried the above calculator using my most optimistic scenario (ie. kentsfield plus SLI plus as much crap as I thought that I could fit in the case) and the max rating was 534W. A more realistic value was around 420W....

And hence I'll look for a 520-600W PSU to provide a bit of a buffer. It will be 3 years before I can conceivably require more, and personally, I think power requirements will go down for many components in the same way as it did for Conroe...

CJM

 

Great article. I think intel have made a good move making quad core available on the dual core socket. The one problem with withe K8L I can see at the moment is if people are waiting for it but need to upgrade now, what can they do, as far as I have read there is no mention of what socket the K8L will be on which also means there is no point buying a kick ass mobo for a AM2 socket and finding that the mobo will not support K8L, which then kinda makes the upgrading a bit fruitless if you were hoping just to swap the CPU. But, quad core is defo the way to go! maybe not for all out gaming performance but that said, once games are multicore coded this probably wont be such an issue.

 

No defense needed

Not a bad defense, except for one little flaw: most software and operating systems can take advantage of a multi processor computer right now. MS Word is multi-threaded already, has been for some time (as has most software applications of any consequence on Windows, Linux/Unix and OSX). Of what benefit would this be to the typical Word user? Have them scroll down through a document with any embedded objects such as images or speadsheets - they'll see the difference.

Or have the user viewing a Word doc in one window while they are backing up their hard drive to a CD/DVD, or installing software, or playing music. All common things for non-power users to do (well, except maybe the backup which nobody ever seems to do - but should).

Browsing? With multi-tabbed, multi-window browsing you can easily wind up with a number of browsing sessions open that are having to handle Flash advertisements/etc. which take up CPU cycles - especially with Firefox which tends to be a CPU hog in that regard. No, it's not going to download the content much faster (if at all), but it may make a difference.

The point is that most apps are now multi-threaded, some quite "heavily" (i.e., make good use of threads to improve performance) and have been for quite a while. This has been the most common complaint I have heard; that software, including operating systems, isn't multi-threaded and won't yet take advantage of multi-processors. That is patently a false assertion and betrays a totally inadequate understanding of how applications and operating systems work, and have worked for some time.

I personally think that 4 cores are about minimum for my purposes for the near future. If I could get a laptop with 4 cores I would. I do development work, so having my IDE (a real memory and CPU hog), SQL Server, Tomcat, my server app and my client app open all at the same time could easily occupy much of the attention a 4 CPU system could give it. Then add to that my email client, Word open to read the requirements document, the bug tracking app, Firefox with a dozen windows open to read various API documents, etc., and yes, I am starting to get there - not to mention having iTunes open in another window, especially if I have the real time spectrum analysis visualizer running. Yes, I have multiple monitors, and no 3 monitors is not overkill - 4 would be the limit for me though.

That said, yeah, I am a power user, but even my mom, who is not a power user, will make good use of her new dual core laptop reading email and browsing the internet while Adobe Elements is processing and printing photos of her grandchildren.

So, don't knock it until you've tried it. I for one welcome as many cores as I can get. I'll always be able to find a use for them.

 

512 Cores anyone?

http://www.channelregister.co.uk/2006/11/06/japan_512-core_co-pro/

 

Couple of questions on K8L...

Is it going to be socket 940 (Opteron as opposed to AM2) and is it going to need DDR2 memory?

AMD has been really good about keeping their server hardware reverse compatible and I'm hopeing I can go to K8L with my existing Mobo.

And next time you're in the Greater Seattle Urban Sprawl, drop me an email and I'll buy you a beer!

 

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

Quad core and beyond can only get better...

 

well said that man!

 

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.

 

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.

 

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???