How Many CPU Cores Do You Need?

In the early years of the new millennium, with CPU clock speeds finally accelerating past the 1 GHz mark, some folks (Ed.: including Intel itself) predicted that the company's new NetBurst architecture would reach speeds of 10 GHz in the future. PC enthusiasts looked forward to a new world where CPU clocks kept increasing at an accelerating pace. Need more power? Just add clock speed.

Newton’s apple inevitably fell soundly on the heads of those starry-eyed dreamers who looked to MHz as the easiest way to continue scaling PC performance. Physics doesn’t allow for exponential increases in clock rate without exponential increases in heat, and there were a number of other challenges to consider, such as manufacturing technology. Indeed, the fastest commercial CPUs have been hovering between 3 GHz and 4 GHz for a number of years now.

Of course, progress can’t be stopped when money is involved, and with folks willing to shell out cash for more powerful computers, engineers set out to find ways to increase performance by improving efficiency rather than relying solely on clock speed. Parallelism presented itself as a solution--if you can’t make the CPU faster, well, why not add addition compute resources?

The trouble with parallelism is that software has to be specifically written to run in multiple threads--it doesn't offer an immediate return on investment, like clock speed. Back in 2005, when the first dual-core CPUs were seeing the light of day, they didn’t offer much in the way of tangible performance increases because there was so little desktop software available properly supporting them. In fact, most dual-core CPUs were slower than single-core CPUs in a great majority of tasks because single-core CPUs were available at higher clock speeds.

However, that was four years ago and a lot has changed. Many software developers have since been hard at work optimizing their applications to take advantage of multiple cores. Single-core CPUs are actually hard to find and two-, three-, and four-core CPUS are now the norm.

Which begs the question: how many CPU cores are right for me? Is a triple-core processor good enough for gaming, or should you splurge on a quad-core chip? Is a dual-core CPU good enough for the average user, or do more cores really make a difference? Which applications are optimized for multiple cores and which ones react only to specifications like frequency or cache size?

We thought it would be a good time to run some tests with apps from our updated benchmark suite (there are still more to come, too), running the gamut of one, two, three, and quad-core configurations to illustrate what multi-core CPUs really offer in 2009.

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  • the Innocent
    This great write up about multi core systems but you did not test one of the greatest benefits to multi core processors true multi tasking. When I was building my new system and was thinking about moving to the Q6600 from my E6550 I had Premier Elements in mind. But It was not only about faster encoding times, it was also about system usability while something was encoding in the background. It was barely possible on 2 cores but very responsive with 4. So you should consider doing some of your tests simultaneously.
  • goozaymunanos
    only "men of war" maxs out my dual core E6750..

    dual-core is FINE for now..don't waste your money on quad core..

    don't forget that quads fit into existing dual-core mobo's, so you can upgrade later..

    save yer ca$h for the graphics card! (like a nice 4850X2)


    p.s. stuff and nonsense:
  • darksun9210
    or if you aren't going to upgrade for a few years, at least this writeup shows that software is getting more "core aware" so to speak. so if you're splashing out on a new rig thats gotta last you, i'd go quad core. as it'll be easier to change your GFX card than upgrade your processor in about 4 years.
    PCI, and AGP have more than outlived the crop of CPU sockets they were introduced with, and PCIexpress is doing the same. So, dual core is fine for NOW. and quads fit EXISTSING mobos. but willl they fit by the time you want to upgrade? not everyone can afford to change machines every 12 months. at least you can pretty much rely on future GFX cards being pci express.
  • evil_tazzy
    Going from dual to quad core is the best i ever did, especialy when you play with multiple eve-online or WoW clients on one pc, and even then it have enough power for the other stuf in the background like msn, jabber, teamspeak and ventrillo, all at the same time
  • skalagon
    Yah I need a quad core and some new ram, waiting 20 seconds for an alt-tab out of WoW is pretty ridiculous, but I guess vista takes its toll too.
  • Anonymous
    Set the screen resolutions of WoW to the same of windows, works wonders for alt tab time.
  • wild9
    This test is just what I've been looking for. Thanks a lot.
  • wild9
    Intel Core 2 Duo Q6600

    Should that be Core 2 Quad??
  • wild9
    AVG Antivirus shows us some wonderful performance gains with multiple CPU cores.

    That result is really impressive, considering the shared access taking place. I would like to see how Spybot Search & Destroy fares..anyone who's ever used that will know it can take an absolute eternity to scan your computer.
  • Anonymous
    Its interesting to note the effect on games. Xbox360 only has 3 cores.
  • mi1ez
    +1 for multitaksing

    running an anti-virus scan while gaming would show the advantage of that 4th core, I'll bet. I've stopped having to disable background processes to game since I went quad and I think that's possibly the baggest advantage rather than flat-out frame rates.

    Good article though.
  • Anonymous
    A good writeup in general but the fact that going from three cores to four has no performance impact needs to investigated further.
    It could be down to the fact that the ageing FSB architecture of the Core processor was the bottleneck and the fourth CPU was starved for memory on some applications.
    Doing the same rounds of tests with the same methodology on a Core i7 system or an AMD quad core CPU would have been a great big help in determining whether going from 3 to 4 cores makes sense.
  • skyline0511
    It should be Core 2 Quad Q6700? Q6600 is 2.4GHz
  • skyline0511
    It should be Core 2 Quad Q6700? Q6600 is 2.4GHz
  • Starky
    No, it was an overclocked Q6600, which is 2.4Ghz stock you're right, but it wasn't running at stock.
    Personally I run my Q6600 at 3.2Ghz, and I love it, can run every game fine, and as this shows, 3DS Max really shines in a quad core environment, and I do a lot of rendering. Autocad (which I also use a lot) gets the same benefit.
  • b3n
    I think a quad-core is essential for multi-tasking.

    As a web developer at work I often have MANY apps. running simultaneously e.g. Flash IDE, Photoshop CS4, Fireworks CS4, audio/music player, PhpED IDE, FTP client, email client, local Apache server, local MySQL server, multiple web browsers (each with multiple tabs open), Subversion client, anti-virus, etc., etc. ... the list goes on!
  • Anonymous
    I don't understand why a controller on the CPU itself can not be responsible for sharing the load across multiple cores, why does this function have to be left to the software. Does a game have to be specifically coded to see the benefits of SLA or Crossfire?
  • Sigfried_alpha
    Only synthetics make well use of the fourth core, what's the matter in the real (not synthetic at all :)) world?.
    Let's go developers!
  • DamageIncM
    It seems like the dual-cores are the power for most applications such as games.
    However, if you want/need a work-horse for like processing many files you would be better off with quad-core.
    As there would be no benefit from quad-cores in 3D-applications and such.
    There is no need to transfer as many files, it just needs to process different things than heaps of files.

    Maybe (or rather probably) games and such applications would eventually start to take advantage of more cores.
    So if you want to be future-proof, you'd have to get a very good quad-core.
    But for now they usually recommend nice dual-cores which is enough to work with.
    Besides, apparently you can overclock the heck out of most anyway.
    They're built better and better and thus should last longer and longer.
  • Gasek
    Multi-tasking works really well with 4 cores.. Reminds me of my Amiga 500 back in the 80s.