What’s wrong with iPhone OS 3.1? I think it’s the RAM.

With OS 3 I had to restart my iPhone every 2-3 weeks. If I didn’t it got painfully slow and problematic apps like Byline would crash.

With OS 3.1 and the same apps I need to restart every 3 days – or spend minutes between screen updates.

I’m not the only one to have trouble with 3.1 ..

iPhone 3.1 problems flood our tip box

In the last week, we have had a constant barrage of iPhone issues break through the lines... so much so that we feel it is our duty to inform the two of you who haven't updated what you could experience by updating to version 3.1 of the iPhone OS. This is no small problem, as you can read from the discussions on Apple's website here, here, here, and here.

The first two links are where we're getting the majority of our tips -- random shutdowns and very poor battery life. The second two, bricked phones and general slowness are still worth a mention -- even prompting our own Erica Sadun to do a live walk-through for debrickifying iPhones…

In my case it’s most likely that the phone is running out of working memory (RAM), probably due to memory leaks (applications that grab working memory and don’t release it). This is likely much less of a problem for 3GS owners, they have twice the RAM of earlier models …

… the actual specs are fairly widely known…

CPU (central processing unit):

original iPhone: ARM 11, 412 MHz
iPhone 3G: ARM 11, 412 MHz
iPhone 3GS: ARM Cortex, 600 MHz

GPU (graphics processing unit):

original iPhone: PowerVR MBX Lite
iPhone 3G: PowerVR MBX Lite
iPhone 3GS: PowerVR SGX

RAM (random access memory):

original iPhone: 128 MB
iPhone 3G: 128 MB
iPhone 3GS: 256 MB

At a glance, you’ll notice that the RAM in the 3GS doubled from past iPhone models. Twice the amount of RAM than you’ve had is never a bad thing, but the reality here is far more noteworthy… The older iPhone models have been often considered underpowered when it comes to RAM, so even though the RAM amount is technically doubled, in actual use, you’ll often be working with 4x to 10x the amount of free RAM. And that’s one major aspect that’s contributing to the overall speedier feel of the 3GS…

Anyone remember the original Mac? It shipped with two little memory to run the OS. The original iPhone situation wasn’t quite as bad, but it was close. It’s likely that the 3.1 update uses more RAM for the OS than the 3.0 release, and the change has moved 3G and original iPhone users into the red zone.

With older phones all-but-inevitable memory leaks are exhausting available RAM in a day or two of heavy use, bringing the phones to a grinding halt. The problem will only be exacerbated by newer apps that expect more available RAM.

The cruel reality is that older iPhones are coming to the end of the line. I don’t blame Apple for that – but I do blame them for releasing OS 3.1 onto phones that can’t handle it. If Apple can reduce OS memory leaks and RAM footprint they’ll redeem themselves (a bit), but clearly future OS releases won’t run on older iPhones.

Apple will either need to move to the two version model they follow on desktop machines (currently 10.5 and 10.6 are both supported, I think there may even be some 10.4 updating going on) or they’ll have to launch some kind of trade-up program for older phones.

Coming from me this is just speculation, but I’m going to install Memory Status and update my results here.

Update: Memory Status was last updated in Dec 2008, so it’s not a good bet for OS 3. I bought iSystemInfo for $1. Shortly after a restart it reports 23MB free (23/128 or 18% free). After using Byline and exiting I have 21MB free.

Update 2: When I make a phone call there's about 3-4MB free during the call. Also, it turns out I didn't need to buy iSystemInfo. I already own "AppBox Pro", a "swiss army knife" product that's subsuming free standing apps like a "Clinometer (level)", Flashlight, Ruler, System Info, Battery Life, Currency Converter, etc. AppBox Pro is giving me approximately the same results as iSystemInfo. Incidentally, AppBox Pro has the ugliest icons ever seen on an iPhone. It reminds me of my old Palm.

Update 9/17/09: The Register on "buggiest update yet". I suspect the problems mostly hit 3G users.