anchor.diff:          | ex -> CouldNotDeleteSource { Request = moveRequest; Message = ex.Message } |> Failure
   
       let compareFiles readAllBytes moveRequest =
  -        let sourceStream = readAllBytes moveRequest.Source
  -        let destinationStream = readAllBytes moveRequest.Destination
  -        if sourceStream = destinationStream then
  -            Success moveRequest
  +        let sourceFi = FileInfo moveRequest.Source
  +        let destinationFi = FileInfo moveRequest.Destination
  +        if sourceFi.Length <> destinationFi.Length then
  +            BytesDidNotMatch moveRequest |> Failure
           else
  -            BytesDidNotMatch moveRequest |> Failure
  +            use fsSource = sourceFi.OpenRead()
  +            use fsDestination = destinationFi.OpenRead()
  +            let BYTES_TO_READ = (int)System.Int16.MaxValue 
  +            let iterations = int <| System.Math.Ceiling((double)fsSource.Length / (double)BYTES_TO_READ);
  +
  +            let one = Array.zeroCreate<byte> BYTES_TO_READ
  +            let two = Array.zeroCreate<byte> BYTES_TO_READ
  +
  +            let areAllEqual =
  +                [0..iterations]
  +                |> Seq.map (fun iter ->
  +                                fsSource.Read(one, 0, BYTES_TO_READ) |> ignore
  +                                fsDestination.Read(two, 0, BYTES_TO_READ) |> ignore
  +
  +                                let equal = System.BitConverter.ToInt64(one,0) <> System.BitConverter.ToInt64(two,0)
  +                                equal)
  +                |> Seq.exists (fun areEqual -> not <| areEqual)
  +
  +            if areAllEqual then
  +                Success moveRequest
  +            else
  +                BytesDidNotMatch moveRequest |> Failure
   
       let copyToDestination ensureDirectoryExists copy moveRequest =
           ensureDirectoryExists moveRequest.Destination
  
positive.code: 
  open Muffin.Pictures.Archiver.Domain
  open Muffin.Pictures.Archiver.Rop
  
  module FileMover =
  
  
negative.code:     let ensureDirectoryExists directoryExists createDirectory path =
          if not (directoryExists path) then
              createDirectory path
  
  