Downsizing Multicore Programming Skills to Take Advantage of Intel Atom
There is no doubt that Intel Atom is an attractive microprocessor. Netbooks, embedded systems, consumer electronic devices, and MIDs (Mobile Internet Devices) are using its different flavors. But can multicore programming skills be useful with these single-core CPUs?
I spent last week attending Intel Developer Forum 2009 where the most popular words were "netbooks," "Atom," "multicore," and "parallelism." I had a great interest on the new Nehalem EX with its 8 physical cores and 16 hardware threads (16 logical cores when Hyper-Threading is enabled). Nonetheless, I was also involved in finishing an application to take advantage of the power offered by a tiny Intel Atom microprocessor running on netbooks and on MIDs (Mobile Internet Devices).
Intel Atom is a very powerful microprocessor. It is a single-core CPU. However, it offers Hyper-Threading, therefore you have ttwo hardware threads, with many shared resources. I wanted to show an application using nice visual effects, displaying images with animations and extra large icons. I had read Stephen Blair-chappell's article Parallel Execution Advantage on Single Core Intel Atom. His experience with an Intel Atom netbook motivated me to design an application with parallelism in mind, trying to take advantage of two hardware threads. It was a really difficult task because I had to target Windows XP, Windows Vista, Windows 7, Moblin 2.1 and Midinux 3.0.
When you target multiple platforms, you usually lose some performance, there is always a trade-off. However, if you design an application with parallelism in mind, you will gain performance in most modern microprocessors, even on Intel Atom. I could improve the overall performance by 35% taking advantage of Hyper-Threading. However, it was not enough to create real-time animations using multiple effects. As Intel Atom also offers MMX; SSE; SSE2; SSE3 and SSSE3, I had the possibility to take advantage of these powerful additional instructions. As I was working with visual effects, I could improve the overall performance by 80%.
Finally, I had the possibility to run the application on stage as part of the keynote launching the Intel Atom Developer Program.
The good news is that you can downsize your multicore and parallel programming experience to target new mobile microprocessors and you'll be able to achieve very interesting performance improvements. Besides, I believe we will see multicore Atom CPUs in the future.
No matter whether you're targeting an eight-core CPU or a tiny single-core CPU with Hyper-Threading, you can go parallel in order to take advantage of the newest micro-architectures.