Why is Flash working so hard on the processor?

Question

I recently heard Steve Jobs refer to this as the main reason for the lack of Flash on iPad

Answer 1

In general, Flash is not hard on the processor; the content of Flash is highly processor dependent. People usually don’t use Flash to display static text and bitmap images, they use it for vector animation, as well as video and RIA with components with a custom shell, and the processor occupies the layout of all these vectors and gradients and alpha channels - regardless of whether you use whether you are Flash or HTML5 or Silverlight or JavaFX or whatever. Feel free to view the demo of this animation comparison and see how CPU usage in HTML5 version comes down to the Flash version. The results vary widely between OS and browsers, but for me (winXP / firefox) the Flash version uses about the same processor as the canvas version (~ 50%), giving a little more than double FPS.

The second answer relates to video in particular, and the answer is: no matter what technology you use to display the video, only two things really affect the use of the CPU: the codec and whether its hardware acceleration is accelerated. You can test H264 video between browsers and the OS and Flash / HTML5 ( and people have done it ), and you will find that the CPU is low, video hardware acceleration, and this is high when it is not like inside or outside of Flash. Thus, there is no problem whether the Flash video is connected to the processor, the only question is whether the Flash video uses HWA or not. Check the full link information, but mostly if you are not using OSX / Safari, Flash video uses the same processor or fewer other parameters.

By the way, if you are also wondering why Flash has historically used more processors for Mac than on PC, even for non-video content, see here for many details - both about why this was worse in the past, and why It improves with Flash 10.1. The quick version is that Apple has added new and more effective ways to connect plug-ins to the browser.

Answer 2

If you look at using a Flash processor, it is significantly higher on a Mac than on a PC. The next release of the flash player (10.1) will make it much better, but not the same as a PC.

I read somewhere that part of the reason is the video. On Windows, applications have access to hardware accelerations to speed things up; on OS X, the required API is not available for using flash. In addition, flash cannot easily use multiple processors, so it is also limited in this sense.

Answer 3

I would say that the main reason is animation and other graphics computing, such as alpha layout, graphics filters, etc., using a processor instead of a GPU. Flash applications that don't come alive aren't very heavy on the processor.

The same can be seen in many recent HTML5 / canvas demos, such as http://9elements.com/io/projects/html5/canvas/ or the intense animation material at http://www.chromeexperiments.com/ , which very processor dependent. Therefore, I would say that this is not a Flash Player as such, which is heavy on the processor, it is that Flash is often used for this.

As for the reasons Flash doesn't work on iPads, I can, of course, just speculate, but one thing that people usually forget is that browser plugins are not allowed on the iPhone / iPad. So things like Unity and Silverlight are also not just for Flash. Java doesn't exist either.

Answer 4

The main reason is that the main requirement of the Flash product is to work on as many PCs as possible. Therefore, the approach developed by the development team was to develop a product that would work on the lowest common denominator of PC hardware. For the most part, this meant that the PC did not have advanced graphics cards.

Given this approach and the lack of serious competition, Adobe is not very interested in changing its strategy. Finally, what has changed in the new version 10, there is a new competition from Silverlight and HTML and a desire to add 3D capabilities.

Of course, Steve Jobs’s objection to Flash has nothing to do with it and really comes down to his desire to control (and charge) for distributing video to his devices.