Quad Core vs. Dual Core Processors

It seems like more and more people these days are misinformed about the true performance differences between dual core and quad core processors.  Let’s be real, there are a lot of people out there that think that a computer system with a quad core processor is “better” than a dual core just because it has twice as many cores.  It’s definitely true that a dual core processor is better than a single core processor, because one core is dedicated to your active application, and the other core is dedicated to your idle applications, therefore speeding up the processing speed of your active applciation.   So what’s the truth about multi-core processors?

The truth about multi-core processors

Before I get started, let’s compare two Intel processors.  The Intel Core 2 Duo E8400 is 3.0 GHz per core with 6MB L2 Cache and retails for $167.99 on Newegg.  In comparison, the Intel Core 2 Quad Q9550S is 2.83 GHz per core with 12MB L2 Cache that retails for $349.99 on Newegg.  Since the L2 Cache is divided equally into each core, both of these processors essentially have the same amount of cache, making them identical processors except for their number of cores.  Since each core is about 3 GHz for both processors, does this mean that the quad core is twice as fast as the dual core processor?
The answer is no!  This is the main misconception that people have about multi-core processors.  You don’t multiply the speed of one core by the number of cores to get the “total” speed of a multi-core processor.  The two processors in this example actually perform at the same speed.  The truth is, less than 1% of software on the market can utilize multiple cores, which means that most of your programs (probably all of them) can only run in one core at a time.  This means that the speed of your programs are fully dependent on the speed of a single core.  You might be thinking “well, what if I’m running multiple programs at the same time?”  The reality is, most programs can perform a task faster than you can switch to another program.  The most notable exception to this rule is video editing software, which usually does utilize all of your cores.
Realistically, you will not notice a difference in speed between a system with a dual core processor and a system with a quad core processor, unless you are running video editing programs.

Conclusion

So what does all of this mean?  Don’t waste your money on a quad core system unless you create and edit videos professionally, or run specialty software that can utilize all of your cores.  You are much better off putting your money towards a dual core processor or system with more GHz and a higher L2 cache.