updated 07:55 am EDT, Mon June 11, 2012
Intel's Mike Bell critical of ARM-based Android CPUs
Intel’s Mike Bell has leveled criticism at Android SoC vendors for not doing enough to optimize their multi-core ARM-based processors for Android devices, reports The Inquirer. According to Bell, Android’s thread scheduler is not yet capable of taking maximum advantage of the multicore processors on the market. Intel’s internal benchmarking of ARM-based SoCs shows that single-core processors can run the Android much more effectively, whereas having additional cores can actually be detrimental to performance.
‘If you are in a non-power constrained case, I think multiple cores make a lot of sense because you can run the cores full out, you can actually heavily load them and/or if the operating system has a good thread scheduler,’ argues Bell. ‘A lot of stuff we are dealing with, thread scheduling and thread affinity, isn't there yet and on top of that, largely when the operating system goes to do a single task, a lot of other stuff stops,’ he explained.
Bell goes on to explain that because Android devices are battery powered and the chips embedded in handsets are thermally constrained, there is not much advantage, if any, in running multiple cores. In fact, it can negatively affect performance – particularly in the way that they have been implemented.
‘If you take a look a lot of handsets on the market, when you turn on the second core or having the second core there [on die], the [current] leakage is high enough and their power threshold is low enough because of the size of the case that it isn't entirely clear you get much of a benefit to turning the second core on,’ he explained. ‘We ran our own numbers and [in] some of the use cases we've seen, having a second core is actually a detriment, because of the way some of the people have not implemented their thread scheduling,’ he revealed.
Bell, of course, has a vested interest in his remarks. After failing to have an Atom chip that was capable of challenging ARM-based devices following the rise of the iPhone in 2007, Intel only recently unveiled the first x86 Android smartphone running its latest, single-core, 'Medfield' mobile processor. However, it is well known that despite the marketing of Android vendors, particularly Samsung, it was only with the arrival of Android 2.3.4 that Android on ARM started making some use of a second core in devices that had them. There also very few apps on the market that currently utilize the second core of an Android device, let alone four.
Despite the current multi-core architectural shortcomings of Android, Bell also blamed SoC designers for not optimizing their chips to better support Android on multi-core processors – they simply ‘have not bothered to do it.’ For Android users, this means not getting the maximum benefit ‘for the size and cost of the part.’ [via WM Poweruser]