[middbrew]

it is not a process that is ended... consider the app as being suspended... living in is own little world and the clock stopped... it (the app) really has no clue what is going on..it is simply in limbo.

Thanks. That makes sense. But isn't that the same thing that happens in QNX?

[goku_vegeta]

The real question is when we are seeing these great demos from TAT and they are using the current gen dual core PlayBook, what can they possibly do if they had 2 MORE cores to utilize? I'm sure if anyone could make use of the quad core in a PlayBook, it would be TAT.

[Innovatology]

The term multi-tasking is a little vague, and is used to describe different things. All modern OS's are multi-tasking, even phone OS's. Otherwise the complexities of receiving a call while playing a game would be huge.

I'm not particularly an expert on the matter, but this is how I understand it...

Mult-tasking from a users perspective: when you swipe from one app to the next, you are bringing one app to the foreground and sending others to the background. Depending on Settings > General > Application behavior, the OS will either continue to run the apps in parallel or "pause" the one that's in the background to conserve battery or improve performance of the foreground app. Despite being paused an app may still receive a little bit of time to do housekeeping tasks, but the OS can enforce a limit on the amount of time it has.

Multiprocessing is the term for describing the fact that the OS and all running apps are "spread" over the two CPU cores that the PlayBook has. It's handled automatically by the OS. It's perfectly possible to run the OS and multiple apps simultaneously on just one core, but having more cores gives us twice the processing power without consuming twice the battery power. It does make it a little harder for the OS to manage the cores. It's certanly not so that one core is for the OS while the other is for apps. Both cores are used to their maximum potential if needed.

The OS is constantly running multiple processes, even when you're not using your device. Each process can have different priorities and scheduling rules. Some of those processes may be apps, others may be services that the OS provides such as listening for incoming calls, checking the battery or sharing files over Wi-fi. Any process, including apps, can run multiple threads, which in some operating systems also have their own rules. So even an app can do multiple things at the same time, e.g. animate the screen and decompress the next picture.

QNX, the PlayBook's OS, is a microkernel-based Real-Time Operating System or RTOS.

RTOS means that the method used to switch back and forth between tasks is predictable, dependable and fast enough for it to be used in situations that require real-time precision, such as engine management of a car, or temperature monitoring of a nuclear power plant. On non-RTOS operating systems like Windows, there is no hard guarantee that a process will be running at a very specific time and able to manage a critical event such as the firing of a spark plug. If there is something else going on that prevents the process from running (paging to disk, for instance) it will just have to wait. For a nuclear power plant, or the brakes of your car, that may not be a good idea. How important all this is for a tablet is debatable, but it probably makes the whole multiprocessing circus a lot smoother & more efficient.

The microkernel model, as I understand it, is a way of seperating tasks, processes, threads, drivers and so on at the lowest possible functional level, and means that the OS can manage the schedules easily and recover from crashes better than monolithic kernel OS's. It's pretty complicated.

A lot more info on the PlayBook's "multitasking" can be read here:
The QNX Neutrino Microkernel

As for the competition, Android and IOS are not microkernel or RTOS, as far as I know, but are also multitasking operating systems. However, on IOS the developer has very limited access to those features. Apple policy dictates that it may only be used for specific functions, such as playing music, and that regular apps are paused or even terminated when the user switches to another app. They claim it is "better for the users" or something.

[OttawaGabe]

Thanks. That makes sense. But isn't that the same thing that happens in QNX?

Yes, same thing. If you start a webpage load, switch to another app, it won't continue to load in the background. Then there's the memory mgmt issue in the Playbook, where after you bring up a few big apps, the others start crashing anyhow.

RTOS on a consumer tablet really isn't of much use. It's not like a car or factory assembly line where you can't wait for a crucial program just take its turn, when it needs to happen NOW.

[middbrew]

Yes, same thing. If you start a webpage load, switch to another app, it won't continue to load in the background. Then there's the memory mgmt issue in the Playbook, where after you bring up a few big apps, the others start crashing anyhow.

RTOS on a consumer tablet really isn't of much use. It's not like a car or factory assembly line where you can't wait for a crucial program just take its turn, when it needs to happen NOW.

Thank man.

[djnshores]

1024 � 768 px 132 PPI for iPad2 , 1024 � 600 px at 170 PPI for playbook , 2048�1536 px 264 PPI for iPad3, this techno babble can explain the difference as to why playbook has a nice screen ( in the pixel/per/inch form=PPI)

The iPad 2 and 3 are both 10" tablets while the Playbook is 7". The bigger the screen the more spread out are the pixels. That is why a Playbook at 170 ppi looks nearly as good as an Ipad 3 with 264 pixels per inch.

A quad core video processor is necessary to push that many pixels around fluidly. I believe the iPad 3 is the upper limit of resolution the human eye can detect. The Playbook has a very good display.

I don't think we need a quad core CPU. For maximum efficiency it requires that the software take advantage of the extra core processors. It's hard enough getting developers to write apps for the Playbook. A quad core just adds more complexity to the programming which I doubt too many programmers will want to commit to.

[DAnklaud]

that really isnt true either. On both android and iOS you are not "restarting" an app at all. If you leave a game, you will resume the game where you left off.

I dont know about games(not much a gamer),but with the apps i use on iOS and 'Droid every time i open another app, then try to go back to the other one"resume", it goes through the loading process again(saving the ram to the disk so it can be reloaded as called for later,kinda like hibernation mode in Windows),and i find half the time i am were i left off,but the rest of the time i am not(fresh page for web,back at a start menu for notes,back to current month in calendars,voice notes halted and saved rather than working in background)and for both of them they (iOS&Droid) act like the Paused mode multi-tasking form of QNX(no realtime showcase mode for either),just another reason i chose QNX for work, and iOS for music,and my rooted 'Droid to to fill the gap (of My needs)

[sf49ers]

that really isnt true either. On both android and iOS you are not "restarting" an app at all. If you leave a game, you will resume the game where you left off.

not completely true, here is a very well written article about IOS multitasking

Fraser Speirs - Blog - Misconceptions About iOS Multitasking

[masqueofhastur]

What multitasking does the PB do? I've asked this before and never got a convincing answer, Yes you can have music in the background and can get new email in the background, but what else? And how is that different from any Android or iOS tablet?

It's less what it does and more how it does it. It's very easy to have things going simultaneously and switch between them very easily. This is in contrast with effectively closing something, opening something else, closing that and re-opening what you had before where you left off. It's much smoother on the playbook.

[masqueofhastur]

The iPad 2 and 3 are both 10" tablets while the Playbook is 7". The bigger the screen the more spread out are the pixels. That is why a Playbook at 170 ppi looks nearly as good as an Ipad 3 with 264 pixels per inch.

No, the PB has 170PPI because of the smaller screen, it doesn't look as good as 264 on a 10" screen, 264 on a 7" screen would look better and 170 on a 10" screen would look worse.

All that's happening here is PB users have no objection to the sharpness of the PB screen, and anything more is just a bonus, so the iPad's increased pixel density isn't necessary for them. Other people however will find it necessary.

[howarmat]

I dont know about games(not much a gamer),but with the apps i use on iOS and 'Droid every time i open another app, then try to go back to the other one"resume", it goes through the loading process again(saving the ram to the disk so it can be reloaded as called for later,kinda like hibernation mode in Windows),and i find half the time i am were i left off,but the rest of the time i am not(fresh page for web,back at a start menu for notes,back to current month in calendars,voice notes halted and saved rather than working in background)and for both of them they (iOS&Droid) act like the Paused mode multi-tasking form of QNX(no realtime showcase mode for either),just another reason i chose QNX for work, and iOS for music,and my rooted 'Droid to to fill the gap (of My needs)

all i can say its app specific and you must be using the wrong ones then. Games on the PB operate almost the exact same as my android tablets and phones. they pause when you leave and then you resume (or you have the option to resume) when you return

[dave1701]

My desktop's Athlon 250 Dual Core will beat out any muti-core tablet CPU for a while to come.

[DAnklaud]

all i can say its app specific and you must be using the wrong ones then. Games on the PB operate almost the exact same as my android tablets and phones. they pause when you leave and then you resume (or you have the option to resume) when you return

Your probably right about me using the wrong apps(my iOS is completely stock,and not much done for my 'Droid except gap-filler,Playbook's perfect for app's no problem there)but i wont bother do'in much about it as my Focus is on the Playbook and learning how to Dev for it (ya i pick up a fair bit of pointers on Crackberry,thank you all,you probably know who you are) because my Playbook is the most useful for my needs,and is One function away from replacing my laptop (seriously, enable USB Host, and the laptop gets replaced)

[kbz1960]

Meet the Power Behind the BlackBerry Tablet OS

[paolap]

Yes, same thing. If you start a webpage load, switch to another app, it won't continue to load in the background. Then there's the memory mgmt issue in the Playbook, where after you bring up a few big apps, the others start crashing anyhow.

RTOS on a consumer tablet really isn't of much use. It's not like a car or factory assembly line where you can't wait for a crucial program just take its turn, when it needs to happen NOW.

@OttawaGabe: switch your PlayBook to Showcase mode (Settings, General, Application Behavior)... if you have it in Default mode it'll pause your apps when in background...