Barney's Blog

Blog archive

Multi-Core Multi-Problems

Multi-core processors have such promise. Imagine: Instead of one CPU, you have two, four, eight, 16 or perhaps many more. Why, your performance would multiply! But performance increases aren't linear -- not even close.

I looked into this subject and found it stunningly complex. The bottom line is that unless a program is specifically designed for cores, there isn't a huge performance increase. Sometimes, apps even run slower because the clock speed on the multi-cores is slower.

Now there's another issue holding back multi-core: It seems that multi-cores can't efficiently use memory. The CPU may be ready to grind away, but the memory can't respond fast enough. One solution? Putting memory right on top of each CPU. Interesting.

Do you have a dual- or multi-core machine? And if so, how does it work? Share your experience at dbarney@redmondmag.com.

Posted by Doug Barney on December 10, 2008 at 11:53 AM