Thank you for replies!
But for i've faced another problem. Our source animation sequences for both platforms contains 15k files. I'll explain better:
1. Towers and units in game can rotate, we splitted rotation in 32 angles(32 AnimationClips), units only have one state for each angle - walk, so when units walk we just play animation for specified angle and switch it to another AnimationClip when unit rotates. Towers have two states - idle and attack, idle have 1 frame of animation, and attack (mostly) have 2 frames, and, of course, towers have 32 possible angles too. We have 6 different types of towers in game, and 5 grades for each type. So, as you can see, we have a lots of content (folder with all sequences, backs for levels and others, takes 814mb on HD). When we start creating SpriteCollections it's was pretty hard to use Asset Server and Unity starts beign very laggy, so we decided to remove all source texture(animation sequences, etc.) after creating SpriteCollection. It's all was created for 1x and 2x platform.
2. When all work about content creation was done. We tried to compile project to see it on iPad 3. We faced problem where Unity just crashes when trying to build project. My first thoughts was about tk2d atlases, as I wrote in first post, some of atlases for 2x platform was greater then 2048x2048. BTW I've submitted bug to Unity and recieved following answer:
"You have a lot of resources folders in your project.
We will look into making unity not run out of memory in that case, but it seems like you are not taking advantage of those folders, so please rename them to a different folder name."
In my project I have two resource folders - my levels prefab and tk2d resource folder. We decided temporarily remove 2x support from project. Because we don't had any source images of our content, we decided rebuild all content of project, without adding 2x platform in "Platforms" settings.
3. When we finished rebuilding I've mentioned one weired moment in tk2d resource folder. All assets in this folder disappeared, but as i remember, they was needed only for multiplatform support, so i've desired that's ok if you have only 1x playform ticked.
It's was preface to my problem. Hope you could understand my ridiculous english.
So, right know, we have huge spike on game scene start. It's looks like most of time goes on Texture.AwakeOnLoad execution. As I understand, Texture.AwakeOnLoad is a process where texture data passes to driver (I also asked this on unity 3d forums
http://forum.unity3d.com/threads/179587-When-texture-get-loaded-to-GPU-and-what-is-Texture-AwakeFromLoad). I don't recieve answer yet when Texture.AwakeOnLoad really called, but I could say when it called in my project. When we had two platforms, Texture.AwakeOnLoad get called on object instantiating in tk2dSprite.Awake(), but when we rebuilded content, as i mentioned earlier, it's looks like Texture.AwakeOnLoad gets called on scene start for all used texture in scene. Also, execution time of Texture.AwakeFromLoad increased greatly. And, as you can see on screenshot, time of execution very different for atlases with same compression and size (RGBA PVRTC compressed 4bit). I absolutely, totally, misunderstanding what happend to project. I hope you could explain why tk2d Resources fodler is empty, why Texture.AwakeFromLoad execution so slow, and why all my tk2d atlases loaded at scene start and not on instantiating as before.
p.s. I greatly apologize for my english, and if you can't understand some of my phrases please tell me, I'll try to explain better. Thank you!