Does anyone anticipate problems with lower memory (256mb?) than iPhone4 (512mb) when we all move to iOS4?

Not really. One of Apple's strengths is backwards compatability. The only real issue is when apps start arriving that require the larger capacity, and I don't see anything coming that I just have to have.

Programs like Epic Citadel already use huge amouts of memory. The key is that the program utilizes the part of the storage memory for the swap file, which is faster than a traditional hard drive.

interesting. i didn't know that

I haven't used an iPhone 4 enough to judge very well. iOS 4.0 crawled unusably on my iPhone 3G (my only other iOS device). I checked specs at Wikipedia:

iPhone 3G:

- Samsung 32-bit RISC ARM 620 MHz processor (underclocked to 412Mhz)
- PowerVR MBX Lite 3D GPU
- 128 MB of eDRAM

iPad:

- 1 GHz Apple A4
- 256 MB DRAM built into Apple A4

So, yeah, I'm hoping 4.2 won't choke my iPad. But I learned my lesson when I upgraded my iPhone to 4.0 and neglected to save the copy of 3.whatever it replaced. (4.1 obviated the need to download it from the web.) When I upgrade my iPad to 4.2, I'm testing it thoroughly before I let iTunes/OS X nuke the 'pad's current OS.

I have an iPhone 3GS and iPhone 4.

The 3GS has the same amount of RAM as the iPad and it seems fine on iOS4.

But keep in mind the processor of the iPad is considerably faster than the the 3GS's, at 1GHz vs 600GHz. At least one test showed the iPad as being about twice as fast as a 3GS.

So I think the iPad will run iOS4 just fine.

As for the iPhone 3G, it is really the same processor and memory as original iPhone (412MHz and 128MB RAM). I wouldn't expect iOS4 to run well on it, but it will run (albeit without key features).



Michael

Gizmodo has a post about the behavior of the dev seed of 4.2 on the iPad:

"It works, just like it does on the iPhone or iPod touch, just bigger … The only thing that sucks is that some apps don't support it yet … And we're wondering if the iPad's mere 256MB of RAM is going to catch up to it now that multitasking's in the mix."

iOS 4.2 on iPad: There's No Going Back

I installed iOS 4.2 Beta 3 on my iPad on October 13th (just after Beta 3 was released), and it runs like a charm! 4.2b3 runs so much better than 3.2.2 and 4.1. I have not come across any apps that won't run in iOS 4.0, and most of my apps do not have a iOS 4.0 Tested Seal in the app description.

As for memory hogging programs, I have the System App, and if I am running low on memory, I just click to free up around 80MB of memory. Usually I can sustain around 100MB of free memory with all the daemons running, and around 3-5 apps in the background. The user is allocated ~190MB in iOS 4.2 Beta 3, and I have not run across any apps that use any where near that much memory, and I have 250 apps installed (NOT jail broken apps). If an app needs more than 100MB of memory, I'm sure the system will deny the allocation, and allocate swap space instead (which is stored on the 16GB/32GB/64GB Flash disk).

Everyone is really in store for a treat with 4.2, as there are tons of improvements!

Hope when it comes out theres "just one more thing".......