Diaries of a Nokia Fan Boy

So everyone has dual core computers, and sure they’re fast, but they consume more power! We only have more cores because we can’t get them to be any faster without the use of liquid nitrogen! But dual core phones? Yes! Won’t that seriously hinder the battery life? No!

I’ve gotten a number of people asking me about why they would want multi-core and I always have to explain that there are, in fact, benefits to running two+ cores on the phone as opposed to one.

To understand why, I first have to explain a little bit of physics behind computing and power consumption.
As everyone knows, the faster a processor, the more power it consumes, and that holds for single-core and multi-core processors. However, what if we put some hard numbers into this? Say we wanted to process twice as much information in the same amount of time. This means that we can either double the processor frequency, to handle twice the operations, or we could toss in an extra core, to have each one handle half the operations. However, what does that mean to our power consumption?
Well if we double the number of processors we obviously double the power consumption to double the workload capabilities. (note: its a little more than double power consumption and a little less than double computational power to account for the extra operating system computations and extra hardware to deal with the extra cores) Now, while the double processor frequency will give us true doubling in computational power, the power consumption will actually increase four times! What if we want to quadruple the computational power? The quadruple in speed will result in 16x the power consumption!

So while the twice-fast-processor may be a tiny bit more powerful than the dual-core processor, it uses nearly twice the battery power!

But how valid is this?
Well we can take a look at the pro’s and con’s of each approach.

Dual core processors have the disadvantage of increased complexity if they are to be fully utilized. Let me explain what that means. Up until a few years ago, software was written for linear execution, and when dual core processors were introduced they didn’t actually perform twice the work because the software couldn’t properly utilize them. Software had to be rewritten to support parallel execution. The same thing is true for phones! Phone software will have to be rewritten to support this new style of processors before the software will actually utilize both cores!

On the up-side, however, the operating system could be slightly modified to allow two programs to run on different cores, thus still producing twice the computation.

Of course, there is another benefit: turning off one of the cores.
If the phone is not performing any computation heave tasks, there is no need for the second core to be consuming power. A similar effect can be achieved with throttling the faster processor, however the power savings aren’t as great as those in the dual core processors and they still add more complexity.

Another issue: heat. Faster processors generate more heat, which becomes a big issue for small devices with no ventilation to speak of.

Finally, processors can only get so fast (just like what happened with computers), and software is becoming more and more demanding on computations. So really, we have no choice! We have to go to dual core, it just so happens that there are also benefits with going to dual core processors!

Which is why I can’t wait for Cortex-A9! But that is a discussion for another day

Hope you found this helpful, feel free to ask questions or just leave comments below. I promise to answer all of them as best I can

-Nokia FanBoy
Posted from my Nokia N95 8GB

Posted by Wordmobi