Is there a texture memory limit for the iPad1 to be taken into account? I am not talking about fps performance, just the memory limit for all my textures before a crash occurs on the iPad?
No, there’s no VRAM, it’s all shared RAM.
–Eric
sorry but I don’t get it, does this mean that there is no limit? If there is, then what’s the difference between VRAM and shared RAM?
Of course there is a limit. I think what he is saying is that there is just one giant clump of memory that is used for absolutely everything on the device - OS resources, app code, heap, textures, audio files, etc. I believe the iPad1 has 256MB of RAM available, but the actual RAM available to your app before the OS kills it is quite a bit lower - maybe somewhere in the 30MB-60MB range? Once our app got around 70MB, we started running into low memory crashes on iPad1, requiring us to refactor our game a bit to reduce this number.
iPad1 is 256mb ram, 100 of which you can use safely before the os gets upset and starts bombarding you with level 2 memory warnings, and quitting your app. Keep your stuff around 100 meg or less. To see how much ram your app ACTUALLY uses, use xcode profiler (instruments).
Technically so far I’ve found that we can use half the available ram of any iOS device before being springboarded. So That’s 128. iOS will let you use a bit more or a bit less before terminating you (it depends if your app releases ram when the os asks it to clean up) and I’m pretty sure your app will not. So keep it at 100 meg or less.
Ok, i did a test with a scene having 35 cubes (50K tri overall) with 35 materials having 35 individual textures (pvrtc4 2.7 Mb each) so 95 Mb of overall textures but in the xcode memory profiler I can only read 20mb under Live Bytes (which is the amount of memory unity is using on iPad), shouldn’t i read at least 95 Mb?
In another scene where I have memory problems, I have 30 objects (90 000 overall) but only 55 Mb of overall textures, if a scene should crash due to memory problems shouldn’t the first one crash and not the second?
*when I decrease the number of textures in the next scene, it doesn’t crash so the crash is due to memory.
*no sound or animation in both scenes.
…what a super answer… ! No wonder that you have over 17000 Posts…! 
Well the Free Memory depend on iOS and how many open APP’s you have …
I found out that i have around 60 - 80MB on iPad 1 before i get trouble…
Personally i try to stay under 60 MB … and all went fine.
But i’m curious what other say to your Results… !
I have been able to have 100 Mb of compressed textures, but my problem is that I can’t monitor the vram of the openGL driver on iPad1, apparently ''live bytes" are not a good reference.
DUDE there is no vram. Just use total memory in use using xcode analyser. Stop leading yourself down pointless paths.
If you are talking about “live bytes” in the xcode allocation profiler then that doesn’t show you the memory used, proof for that: i have 90 Mb of compressed texture and it’s showing 50 Mb.
Where do you check this "total memory"option?
You might be able to track it by monitoring the VM usage objective c - retrieve video ram usage iphone - Stack Overflow
So if the iPAD2 has 512 MB of memory, it will be safe to use 256 MB in Unity?
But if the iOS uses around 100 MB for backgeound processes wouldn’t be also safe to use around 400 MB of memory?
No. Re-read what people have said about what uses memory and how it works. To be safe with iPad 2 you have less than 200mb or even 150mb… depending how are you using it and what are you mempeaks