title: SDWebImage insane memory growth, high virtual memory? High dirty memory size. Video Attached
body: <p>I'm having issues with a very content rich app I'm developing. I'm using SDWebImage for caching and loading images asynchronously to my UIImageViews and UIButtons where applicable. Within this app I have content feeds which are collections views of 3 columns wide of pictures loaded from a server URL.</p>
  
  <p>As I scroll, memory builds up like crazy but does clear itself when it needs to as is the expected behavior of SDWebImage. However, this application is a tabbed application, so if I scroll through one feed partially, switch tabs and scroll through a feed on another tab - memory just builds and is not getting cleared.</p>
  
  <p>The first issue here that I do know is that the image size are very big and being scaled down inside the app rather than being downloaded in the right size of 100x100 PX, instead they are 640x640 px. This is obviously going to be fixed as each image needs multiple sizes for various displays throughout the app, and this will lessen the speed of the growth of the VM, but I don't believe it will solve the underlying issue of memory eventually getting to the point of crashing the app while navigating through different pages.</p>
  
  <p>I notice apps like Wanelo and Path and Facebook all have infinite feeds with massive amounts of content that can scroll and load indefinitely without any noticeable loss in performance of crashes, how are they doing this?</p>
  
  <p>I've also included a video with annotations of me profiling the my application with the allocations template in instruments. I can read the info OK, but I'm not sure if there's something I'm missing as far as allocations / call stack / etc goes that could possibly lead me in the right direction of solving this.</p>
  
  <p>Video of profiling available here: <a href="http://youtu.be/J4zici41TMs" rel="nofollow">http://youtu.be/J4zici41TMs</a> </p>