How much memory, really?

[jayducharme]

I had heard the the iPhone 4 had a whopping 512 mb of memory. But when I launch System Activity Monitor, the total of all memory (free and in use) comes to about 236 mb. Am I missing something? Is SAM wrong? Or does the iPhone 4 only have 256 mb max?

EDIT: Okay -- this is weird. I just closed every application that was sitting in the multi-task bar (about a dozen). Then I reopened SAM. I had a total of about 445 mb of memory. What gives? Do apps in the multi-task bar sequester memory? I thought they weren't supposed to consume resources.

 

[Benji222]

They are kept in a frozen state as ram. Yes its dumb.

 

[jayducharme]

And that would explain why multi-tasking is not supported on the 3G. It would choke. Thanks for the clarification.

 

[mrtune]

They are kept in a frozen state as ram. Yes its dumb.

Why is it dumb? Unused ram is wasted ram. The OS is smart enough to dump saved state chaches from memory as it's needed so that you don't have to manage open apps like you would on other phones. This is a simple and effective way of doing it IMO. One less thing I have to do. I don't want to manage open apps, I just want to use the phone.

I remember before the iPhone when I used blackberrries and windows mobile phones. It was a pain in the ass. Every so often the phone would slow to a crawl because of open apps and I would have to either restart it or open the task manager and start closing stuff out. Something that has not given me issues on the iPhone, ever. I've been an iPhone owner since day 1 back in June of '07, upgrading yearly since then.

 

[admanimal]

They are kept in a frozen state as ram. Yes its dumb.

So it would be better for recently used apps to not be in RAM and have to be relaunched from flash every time they are run? Not only is this slower, but it also uses more battery power. These facts coupled with the fact that the system will automatically kill background apps when a foreground app does need RAM makes the way it works the exact opposite of dumb.

 

[Applejuiced]

Why is it dumb? Unused ram is wasted ram. The OS is smart enough to dump saved state chaches from memory as it's needed so that you don't have to manage open apps like you would on other phones. This is a simple and effective way of doing it IMO. One less thing I have to do. I don't want to manage open apps, I just want to use the phone.

I remember before the iPhone when I used blackberrries and windows mobile phones. It was a pain in the ass. Every so often the phone would slow to a crawl because of open apps and I would have to either restart it or open the task manager and start closing stuff out. Something that has not given me issues on the iPhone, ever. I've been an iPhone owner since day 1 back in June of '07, upgrading yearly since then.

Exactly, its not dumb.
Its actually the smart way of doing it without causing slowdowns or battery drain.
Some people are clueless......

 

[mgamber]

It's just another form of caching. Why would you want "free memory" on any system? Ideally, you don't want any memory sitting there unused, ever.