"7. Hardware Compatibility
7.6. Memory and Storage
7.6.1. Minimum Memory and Storage
Device implementations MUST have at least 340MB of memory available to the kernel and userspace. The 340MB MUST be in addition to any memory dedicated to hardware components such as radio, video, and so on that is not under the kernel's control."
In translation it mandates 512 MB of RAM for ICS, as not only Android is using the memory.
Also OpenGL 2.0 is a requirement according to the doc.
8. Performance Compatibility
The following applications should
launch within the specified time.
Browser: less than 1300ms
Contacts: less than 700ms
Settings: less than 700ms
Rightly described memory issues in the article. Not only ICS, but even gingerbread tends to kill launcher often. So when returning from memory consuming app, you end up on empty screen with only a wallpaper, and only then launcher is starting. On Pulse at least.
Never a case on 512 MB device.
from the referenced Sony blog:
"ICS was developed with Galaxy Nexus in mind, which is based on a TI platform with dual-core processor and 1GB RAM."
"We are now adapting ICS to run on our 2011 Xperia™ smartphones, which are all built on a Qualcomm platform with single core and 512 MB RAM. "
All is correct. But said are the only differences.
Only drawback is that keypad lights will not work, as no compat patch for lights is in that kernel.
Kernel smaller size is due to better compression. But it comes at mall cost:
- After decompression it will be bigger in memory as already more functionality is it it - ext3/4 and IPv6. But it's insignificant - no more than 200 KB extra.
- Also it takes slightly more time to decompress better compression - extra several sec - 3/4 ? - on initial boot.