Do you need a Quad-core CPU?

Intel Quad CoreUnless you’re a hardware enthusiast, you may have missed the fact that Intel significantly lowered the price on it’s quad-core CPUs this weekend. A quad-core CPU has four processing units on one chip (this first quad-core from Intel is actually two dual-core CPUs on the same chip). With the price drop, a quad-core CPU can now be purchased for just a little more than a high-end dual-core. Four CPUs for the price of two. Sounds like a good deal, right?

Well, not so fast. Unlike clock speed increases, multiple cores don’t scale linearly. While a 2ghz CPU is twice as fast as the same CPU at 1ghz, a quad-core CPU is not four times as fast as a single core. Like most desktop technology, quad-core CPUs have migrated from the server market. Comparing server performance using round numbers, a dual-core CPU offers about a 50% performance over a single core (not 100%), and there are diminishing returns. A quad-core CPU is only about 25% faster that a dual-core CPU.


Running multiple cores is very complex. The performance varies depending on hardware configuration, software etc. Those four CPUs are sharing bandwidth on the motherboard used to access RAM, hard drives, video, etc. In addition, very little software has been optimized to utilize four cores, even less mainstream, consumer software for the desktop. Photoshop, and a handful of new games come to mind. It’s very difficult to write multi-threaded applications that utilize multiple cores. Developers are still learning. It’s likely many years until the majority of mainstream applications are able to use multiple cores. There is also added overhead associated with managing multi-cores in both the chips microarchitecture, and the operating system.

Operating system like Windows, Linux and OSX are multi-threaded, and support splitting applications between CPUs. While this make sense for a dual-core system on the desktop, it would very rarely require four CPUs. For example, modern CPUs are able to multi-task common applications very easily. Only things like a virus scan, or ripping a CD require two CPUs to allow the system to work on different tasks without slowing. But, how often are you going to be encoding a video, running a virus scan, unpacking compressed files, and surfing the Internet with a half dozen other applications open, all at the same time?

Will you have a choice? Here is an example from the web server segment. If you want a web server, you can now get a quad-core, for the same price as a dual-core from many vendors. However, due to it’s higher clock speed, the fastest web server for most applications is not a quad-core, it’s a dual-core Xeon 5160 (Woodcrest). Because of the TDP (thermal dynamic profile) of a quad-core CPU (Clovertown), it’s not clocked as high as the dual-core. They simply generate too much heat. The fastest quad-core CPU available is clocked slower than the fastest dual-core CPU. Intel needs adoption of quad-cores in the server market. So what do they do? They’re discontinuing the faster dual-core Xeon 5160.

Ready or not, the quad-core CPUs are coming to the desktop, and again Intel is pushing them with marketing, and low prices. I’m guessing soon they’ll eliminate the faster dual-core chips, as they’ve done in the server market, and it may cost you. Instead of a dual-core system that would run the applications that you use the most faster, you may be forced into a quad-core with a lower clock speed, and a higher system price. Quad-cores are hungry. From amount and speed of the RAM, to the size of power supply and motherboard performance, quad cores have higher requirements.

How did we get here? Intel started on this path a couple of years ago when they were unsuccessful reaching the clock speeds that they had hoped with the Pentium 4. With the marketing department unable to sell clock speed, a new feature was badly needed. Moore’s law meant that CPUs were still doubling their number of transistors every 24 months, and provided the answer. CPUs had already added features for multi-media and huge on die memory caches. Multi-cores provided another way to utilize these extra transistors, while taking the focus off of clock speed.

No doubt that multi-core CPUs are the future. Intel has promised 80 core CPUs in five years. I’m not sure that we’re ready for four.

  • admin

    I'm curious, has anyone recently 'upgraded' from a Core2 Duo, to a Core2 Quad? Notice any performance improvements, or system stability issues. Was the Quad core upgrade a noticeable improvement?

  • Railgun_Livewire

    I just upgraded to a Q6600 and its like I strapped a supercharged V8 to my motherboard.

    dont be fooled by the skepticism, quads are worth every penny!

  • Railgun_Livewire

    I just upgraded to a Q6600 and its like I strapped a supercharged V8 to my motherboard.

    dont be fooled by the skepticism, quads are worth every penny!

  • Dual core is good enough for todays application for windows xp.

  • Dual core is good enough for todays application for windows xp.

  • jhilson

    Very good article. Just like in auto mechanics, not just because you have a big engine your car will be faster in every dimension. You'll need a well designed transmission, a proper intake and exaust system and enough fuel injector capacity among others.

  • jhilson

    Very good article. Just like in auto mechanics, not just because you have a big engine your car will be faster in every dimension. You'll need a well designed transmission, a proper intake and exaust system and enough fuel injector capacity among others.

  • aCi11i3s

    I'm currently running a Kentsfield on my nForce 680i, and thx to the heavens for both. running games like Crysis at max settings, and runs smooth as a top. great if you require or want this type of performance for the latest games or apps. The quad is aided by a 1000wPSU, 2gb @ 1066mhz, and (2)8800gtx's...these do help out a bit too.

  • aCi11i3s

    I'm currently running a Kentsfield on my nForce 680i, and thx to the heavens for both. running games like Crysis at max settings, and runs smooth as a top. great if you require or want this type of performance for the latest games or apps. The quad is aided by a 1000wPSU, 2gb @ 1066mhz, and (2)8800gtx's...these do help out a bit too.

  • jim

    doubtless quad cores will be faster then duals, it's just logic, you don't need to be a geek to work that out. But I think it's a question of if you really need it, I mean if you're running XP and all you're doing is IE, MSN and the like you're not going to notice any difference between Duals and Quads, I reckon it's only gonna benefit you if you want to really stretch the limits of your system.

  • jim

    doubtless quad cores will be faster then duals, it's just logic, you don't need to be a geek to work that out. But I think it's a question of if you really need it, I mean if you're running XP and all you're doing is IE, MSN and the like you're not going to notice any difference between Duals and Quads, I reckon it's only gonna benefit you if you want to really stretch the limits of your system.

  • Dan

    Fantastic article. Best I have seen that describes. I like how you went into the history and marketing on the cpus to describe how it was and where its going.

  • Dan

    Fantastic article. Best I have seen that describes. I like how you went into the history and marketing on the cpus to describe how it was and where its going.

  • Kris

    Good article I was going to but a quad core but I decided to but the E6850 core 2 Duo 3.0 ghz. Hop I made the right choice. Besides I don't even need a Quad Core yet maybe in the future. I like your style of writing.Oh I wonder how much the 80 core is going to go for.

  • Kris

    Good article I was going to but a quad core but I decided to but the E6850 core 2 Duo 3.0 ghz. Hop I made the right choice. Besides I don't even need a Quad Core yet maybe in the future. I like your style of writing.Oh I wonder how much the 80 core is going to go for.

  • Kevin

    Good article.

    Quad core is aimed more at the gamers and people that need a stronger machine. So I feel that more often then not it is worth the extra money.

    I'm running a Q6600 and what a dream. Nice to know that this will be the CPU to go for when more applications come out the will use all four cores. Also something to note. This CPU is like heaven to overclock. And so are most of the quads I understand. Makes sense as each core can handle more strain cause it can offload extra processes to the next core.

    • Anonymous

      I'm not even sure gamers need quad performance as most games do not support any advantages of it. Quad core is really about parallel resource usage. As for example running multiple tasks or programs and having those tasks use one core thats available. Thus slowing down the machine less. Its not really about speed, its about keeping average throughput constant over multiple tasks.

  • Kevin

    Good article.

    Quad core is aimed more at the gamers and people that need a stronger machine. So I feel that more often then not it is worth the extra money.

    I'm running a Q6600 and what a dream. Nice to know that this will be the CPU to go for when more applications come out the will use all four cores. Also something to note. This CPU is like heaven to overclock. And so are most of the quads I understand. Makes sense as each core can handle more strain cause it can offload extra processes to the next core.

  • dina

    What about servers? will there be any difference for example for a streaming site?

  • dina

    What about servers? will there be any difference for example for a streaming site?

  • manish dixit

    it will always be the man behind the machine, the winner.

  • manish dixit

    it will always be the man behind the machine, the winner.

  • chris

    WHAT A CRAP ARTICLE. Time has proven the author wrong.
    The auther assumes intel will stop selling deuces, but we have the i3, and even single cores for tills etc. . There will always be a market for lower range products so intel will make them.
    The guy is paranoid.

  • Noeuruta2009

    miraaa ccapullooo ponlo en español que no lo entindoo 😀