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John Carmack's Cell Phone Adventures
Mr. Carmack has updated his blog with news of his latest interests. Apparently mobile gaming on cell phones has consumed a large portion of his time of late, and he has some witty commentary on programming for the emerging game platform. From the article: "I'm not a cell phone guy. I resisted getting one at all for years, and even now I rarely carry it. To a first approximation, I don't really like talking to most people, so I don't go out of my way to enable people to call me. However, a little while ago I misplaced the old phone I usually take to Armadillo, and my wife picked up a more modern one for me. It had a nice color screen and a bunch of bad java game demos on it. The bad java games did it."
I did try running that benchmark, but it won't load on the i730 (score one more for run-anywhere...).
..." comparisons from the benchmark are against purely interpreted java on the P3, which is about 1/10th the speed of a native implementation, and benchmarks that focus on expression and control operations will overestimate relative performance for applications that are array access heavy. Still, if a java app on that phone performed like a P3-100mhz, it would be pretty impressive.
One of our test platforms is a fairly high end Sony Ericsson, which is 10x as fast as our Motorola base platform. For a 128x128 screen, the Motorola renders about 4 fps and the Sony renders about 40 fps. Compare with Wolfenstein-3D performance (the DoomRPG engine has some extra graphics features, but it is still in that general class) at that resolution on older systems. A 386-16 would go significantly faster.
Note that the "As fast as a
It is true that a good JIT (which the phones don't have) can make java code go nearly as fast as C/C++ code that is written in the same style. The "in the same style" part is often overlooked -- in lower level languages you often have options for implementation with pointers and CPU tailoring that would make the code look very different, but go significantly faster.
I still generally like java, and maximizing performance is only important in a rather limited subset of software engineering.
John Carmack