gistfile1.m

    
    CALayer *mask = [CALayer layer];
    mask.contents = (id)[[UIImage imageNamed:@"student_image_mask"] CGImage];
    mask.frame = CGRectMake(0, 0, 80, 80);
    
    [imgView.layer setCornerRadius:40.0];
    [imgView.layer setBorderColor:[UIColor whiteColor].CGColor];
    [imgView.layer setBorderWidth:3.0];
    [imgView setBackgroundColor:[UIColor colorWithWhite:220.0/255.0 alpha:1.0]];
    imgView.layer.mask = mask;
    imgView.layer.masksToBounds = YES;
    imgView.layer.shouldRasterize = YES;
    imgView.layer.rasterizationScale = [[UIScreen mainScreen] scale];

//    [[self collectionView] setFrame:frame];
//    [[self collectionView] setClipsToBounds:NO];
//    [[[self collectionView] layer] setBorderWidth:1.0];
//    [[[self collectionView] layer] setBorderColor:[UIColor colorWithWhite:65.0/255.0 alpha:1.0].CGColor];
//    [[[self collectionView] layer] setShadowRadius:100.0];
//    [[[self collectionView] layer] setShadowOpacity:0.5];
//    [[[self collectionView] layer] setShadowOffset:CGSizeMake(1.0, 1.0)];
////    [[[self collectionView] layer] setShadowPath:[[UIBezierPath bezierPathWithRoundedRect:[self collectionView].bounds cornerRadius:0.0f] CGPath]];

I bet just ditching the shadow is what you need to do. For some reason I can't apply the shadow along the path like that... It's offset and looks weird. Give that a try and let's see how things are. If we need to, we can drop the shadows for 1.0 and then see if we can git things more performant in 1.1.

I took another look at this. You have the shadow radius set to 100.0. That completely crushed the UI. I took it back to 1.0 and it's MUCH better. I'll get it checked in.