Comments on: TiPb SMASH: the iPhone and Multitasking Misconceptions

By: roxmo

roxmo — Tue, 20 Jan 2009 04:59:18 +0000

Say, and what’s the real reason we’re still MMS deprived? Can’t they just limit the size of the message, if they’re afraid people might exchange songs?

By: D. Haas

D. Haas — Mon, 19 Jan 2009 20:06:12 +0000

@Jeffdc5, @Bob, @George

You guys hit it on the nose. The hardware, and the way the OS is implemented, hinders true multitasking on the iPhone.

I don't like the fact that 75% of iPhone's RAM goes only to the OS and it's processes. That's heavily bloated for an OS, Apple should have looked into offering 256MBs of RAM on the first gen, or at least the second gen iPhone. Although I disagree on one part George: allowing for virtual memory isn't essential for multitasking. Symbian and WM do multitasking without virtual memory. Also, with tthe limited write cycles of flash/SSD memory, it kinda forces mobile OS makers to refrain from using virtual memory (shouldn't ruin someone's phone by using a constantly rewritten-to-flash swap file on the phone).

@Andy, There are a ton of good 'backgroundable apps' that I'm sure are well written. AIM, Yahoo, BeeJive, Weatherbug, for examples, had good experience writing programs and I doubt their apps would be an issue. Although it's possible some apps are badly coded and may be memory hogs, it's fairly easy to tell how badly they are, even in iPhone's sandbox environment.

By: Andy

Andy — Mon, 19 Jan 2009 13:21:35 +0000

Apple doesnt want people messing with its OS. Other phones have issues such as memory leak due to poorly written apps but that is the price you pay for having apps run in the background. You will likely end up having to reboot your phone or have 3rd party apps crash with a lot more frequency.

By: jon

jon — Mon, 19 Jan 2009 10:55:13 +0000

And btw, the kind of “multitasking” mentioned in this article (having music, browser running in background), is done on my 3 year old sony ericsson k750 feature phone…nothing special there. Almost all features phones do it now.

By: jon

jon — Mon, 19 Jan 2009 10:53:14 +0000

I hope they change the OS to alow it. What frustrates me more on the iphone, after havinga Sony Ericsson P1i (running Symbian UIQ3) is precisely this. On the P1, with the same 128mb of ram, i could easily run 10,20 apps at the same time if i wanted. I had podcasts being pushed, two browsers, fring and other IM client, email client, running at the same time, plus the music player, lots of times. And no, the battery life did not suffer much. And no, the phone was still stable. So, apple has lot to do in this area…even with 128mb of RAM they should do better. Right now is difficult…i´m using backgrounder (jailbreak), and i can run Beejive on background…however, if i try to load anything else, beejieve is normally terminated

By: frog

frog — Mon, 19 Jan 2009 08:33:48 +0000

iChat running in the background would solve the majority of issues users have with multi-tasking. Maybe Apple can just go down that road. I don’t want to have to wonder about background apps for the most part, IM is the only issue I have.

By: George

George — Mon, 19 Jan 2009 05:51:35 +0000

The iPhone's OS currently does not support virtual memory which is essential for multitasking. As such, all multitasked apps have to fit into the 128 MB RAM space, which really isn't sufficient to support many apps running simultaneously. Apple can design some of its internal apps to run with very small memory footprints when running in background mode. But without virtual memory, there is no way you're going to be able to run any arbitrary 3rd party app in the background.

Apple could (should) have provided an API so that apps could enter a background mode where their memory allowance is greatly decreased (say, 5 MB tops) and where all of their UI views and such are destroyed. But I'm sure schedule pressure to get the iPhone out prevented them from doing this. Instead, they suggest that all apps provide the illusion of multitasking so that when the user switches away (closes) from the app, the app should save state, so that when the user comes back into the app, they pick up from the same screen they left off at. This works for many scenarios, but obviously not for the ones that require real multitasking (like audio apps or IM, auction, and weather apps that need to provide real-time notification of events).

By: G

Mon, 19 Jan 2009 03:59:42 +0000

You both have a very limited vision of what multitasking enables. There is an entire class of applications that could benefit from background processes without slowing down the rest of the phone, given an aggressive process scheduler. To take one example, RSS feed readers. Currently, when a user starts up Byline or NetNewsWire, he/she has to refresh the feed list before doing anything. When a phone is idle 85% of the time, there is simply no good reason why a a user should have to perform that task himself/herself. The iPhone should be able to fetch that content at preset intervals, like every other phone/rss reader can. Apple could institute this with as an aggressive a process scheduler as their current foreground program manager — if any other application is running in the foreground (or a “big 4″ app, e.g. ipod, in the background), deny a background processes any resources, or, do not allow it in the first place. If anything was running, the only extra process running would be Apple’s scheduler, determining what resources should be doled out — and that scheduler is already running. These sort of wake-and-sleep proceses would be useful for a wide range of applications, and would not impact user experience, unless the task scheduler was asleep at its own wheel. Since OSX (and Mach) already has a solid task scheduler, hopefully Apple will open it up at least this much, seeing as PNS seems at best indefinitely delayed.

By: Bob

Bob — Mon, 19 Jan 2009 03:11:06 +0000

Jeffdc5 nailed it. While multi-tasking is possible today via Backgrounder, the reality is that the iPhone is so RAM-constrained that it’s rather pointless. A minor bump up to 256mb along with external notifications (e.g. their patent apps, or even a flashing LED) would get me to buy into a new hardware platform – even without Rene’s coveted iPhone HD capabilities.

By: Jeffdc5

Jeffdc5 — Mon, 19 Jan 2009 01:03:41 +0000

The problem I have is safari needs a lot of ram to run having it and other apps running makes the iPhone run slower I don’t see any big time multitasking untill we get a more powerful iPhone