Sprite Kit and Pathfinding, differences between iPad and iPhone? - iphone

Question

I wonder if there is some setting och significant difference between iPad and iPhone?
I'm developing a game with Sprite Kit, SKD 8.1 and target iOS 7.1.
The game is using A* pathfinding to move the 2 characters on my map during the testing.
The problem I've encountered is when the characters looking for a path.
On my iPad 4, 16gb, the pathfinding freeze while the characters looking for a path.
On my iPhone 6 and iPhone 4, it works flawlessly.
It works great on the simulator (iPad Retina, iPhone 4 and iPhone 6) and there is no freeze in the game, only on my Ipad 4...
Is there something I've missed? The game is developed to be used both on iPhone and iPad.
Very grateful for any help ..

Answer 1

-(NSArray*)nearbyBlocks:(SKNode*)blocks {
NSMutableArray *tmp = [NSMutableArray arrayWithCapacity:4];
NSArray *leftB = [blocks.name componentsSeparatedByString:#"_"];
/* LEFT */
SKNode *b = [background childNodeWithName:[NSString stringWithFormat:#"block_%i_%i", [[leftB objectAtIndex:1] intValue]-1, [[leftB objectAtIndex:2] intValue]]];
if ([blockArrayWalk containsObject:b]) {
[tmp addObject:b];
}
/* RIGHT */
b = [background childNodeWithName:[NSString stringWithFormat:#"block_%i_%i", [[leftB objectAtIndex:1] intValue]+1, [[leftB objectAtIndex:2] intValue]]];
if ([blockArrayWalk containsObject:b]) {
[tmp addObject:b];
}
/* UP */
b = [background childNodeWithName:[NSString stringWithFormat:#"block_%i_%i", [[leftB objectAtIndex:1] intValue], [[leftB objectAtIndex:2] intValue]+1]];
if ([blockArrayWalk containsObject:b]) {
[tmp addObject:b];
}
/* DOWN */
b = [background childNodeWithName:[NSString stringWithFormat:#"block_%i_%i", [[leftB objectAtIndex:1] intValue], [[leftB objectAtIndex:2] intValue]-1]];
if ([blockArrayWalk containsObject:b]) {
[tmp addObject:b];
}
return [NSArray arrayWithArray:tmp];
}
I've run Time Profiler now and it spikes when the character is looking for a path. The search for childNodeWithName is at yellow with 24%... nearbyBlocks is called every time the path has found the next block so its called multiple times depending on the path length.
The problem is that I need to use the SKNodes because the char can fall down if someone is removing a block underneath... Might abandon the game idea soon ;)