Upon posting my initial thoughts on the Nokia N8, I received a comment which noted, “if it is an old ARM11 rather than ARM8, it will be slow and will fail.” This hit me on a couple levels, and after typing a lengthy comment I thought I’d instead make my response into a post which may catch some more issues and debate.
Clock speed as a poor indicator
As I see it, the trouble with any MHz war is that it often misses the point of the capabilities of the chips themselves. Sure, it is rather easy to say that a modern 3GHz machine is going to beat out a Pentium 200MHz, and by that measure we can extract some meaning. An order of magnitude is a pretty sizable difference, and assuming that processors are made in about the same kind of way there’s a low enough margin of error to assume that one will trounce the other.
In general, though, MHz are not the all singing landmarks of how well a processor works. Years ago, Intel had pushed their clock rates up and up, even though they didn’t do quite as much per cycle. This sold more chips, because the numbers were higher and marketed in a way that convinced people they were uniformly better.
AMD, on the other hand, eventually went towards marketing their chips not by the MHz/GHz, but by performance ratings. I’m not saying that worked out for them in the end, though the reality is that per-cycle, AMD chips generally did more than their contemporary Intel counterparts.
If you want to read further on the subject, Wikipedia has a good article on Clock rate which is worth a gander.
Efficiency is what will drive the future
The next step for processors at this point is less about the clock speed, and more about the efficiency in terms of power usage. For years, desktop computers have been plugged into the wall, and they haven’t varied all that much in how much power they’ve consumed. Indeed, because there haven’t always been quite as many options, with Intel leading the industry by leaps and bounds, we buy and use what’s available. We may shut our computers off or put them to sleep at night, though since the power outlets are almost always available and plentiful, power hasn’t been that much of an issue.
Mobile devices, to include not only phones, but now laptops and tablets of all sorts, are a different issue. Our computers are getting smaller, more portable, and, most importantly, untethered from the wall sockets. While battery technology has improved in certain degrees over the past ten years, we are still rather handicapped by modest power requirements. The trend, then, is that our processors must be efficient: fast enough to do what we need to get done, but also conservative enough to not require bulky batteries or constant recharging.
Back to the Nokia N8, the device is set to have an ARM11 at 680MHz, with a graphics co-processor supporting OpenGL-ES 2.0 (note: for further details on the N8, check out the Forum Nokia website). D.J., the original commenter, most likely had meant the Cortex-A8, not an ARM8 in his original post; and the Cortex-A8 is certainly a newer chip design than the ARM11. While it’s probably safe to assume that the Cortex-A8 is a faster chip, I haven’t been able to find any numbers on power efficiency. These are the kinds of numbers that sound important to me.
Integrated GPUs also important
The second side of the progression of processors is with the GPU, or graphics processor. Back again to the N8, I found it refreshing that a requirement of Symbian^3 is a graphics co-processor in order to handle graphical tasks. If I had to pick, I’d choose a longer battery life and boring responsiveness over fancy transitions, animations, etc. in the UI: all of that crap doesn’t make me work any better or accomplish any more. If the flashiness is going to be there, however, I do think it’s important to be smart about which hardware to use.
In the case of a GPU handling graphical niceties, I then don’t particularly see why I need all that much in terms of a CPU. The OS depends on lean code that is written properly, and at the end of the day those enhancements will have much greater effect on the reactiveness of the device than the difference between 600MHz and 800MHz. Symbian may be “old,” though said another way it’s been around long enough to go through iterations and optimizations on a much larger scale. In that sense, I hope that Symbian does stay old, in certain respects, to avoid unnecessary bloat. Essentially, having great integer performance can be meaningless in the face of high floating point requirements, and I’m rather confident that the ARM11 in the N8 will be more than enough.
One final note re: GPUs in integrated devices, I find it interesting that the desktop systems are also converging somewhat in this space. I’m incredibly pleased with my new Intel Core i3 chip, which has a capable, integrated GPU in the CPU die. The result is that I’m getting 1080p video playback and adequate gaming capabilities without the cost of a video card, in a processor that costs less than $120. It’s a rather incredible feat, which as time goes on will also find itself in the mobile space more and more as a standard.
Conclusion
All in all, what I’m saying here is that it’s important to take a step back from the tricks of marketing, and to think about mobile devices in many more dimensions than the clock speed of its CPU. Software, graphics co-processors, and power efficiency are all, in my opinion, more significant indicators of how well a device will perform, and thinking in this way can lead to a better picture about what is actually in play for these future devices.