diff --git a/src/download/src/lib.rs b/src/download/src/lib.rs
index 25a27ac2eb..01855f4277 100644
--- a/src/download/src/lib.rs
+++ b/src/download/src/lib.rs
@@ -76,7 +76,7 @@ pub fn download_to_path_with_backend(
                 if let Some(cb) = callback {
                     try!(cb(Event::ResumingPartialDownload));
 
-                    let mut buf = vec![0; 1024*1024*10];
+                    let mut buf = vec![0; 32768];
                     let mut downloaded_so_far = 0;
                     loop {
                         let n = try!(partial.read(&mut buf));
@@ -102,7 +102,7 @@ pub fn download_to_path_with_backend(
                         .create(true)
                         .open(&path)
                         .chain_err(|| "error opening file for download"));
-                        
+
             try!(possible_partial.seek(SeekFrom::End(0)));
 
             (possible_partial, downloaded_so_far)
diff --git a/src/rustup-dist/src/dist.rs b/src/rustup-dist/src/dist.rs
index 48236bf582..31520f8017 100644
--- a/src/rustup-dist/src/dist.rs
+++ b/src/rustup-dist/src/dist.rs
@@ -502,6 +502,23 @@ impl ops::Deref for File {
     }
 }
 
+fn file_hash(path: &Path) -> Result<String> {
+    let mut hasher = Sha256::new();
+    use std::io::Read;
+    let mut downloaded = try!(fs::File::open(&path).chain_err(|| "opening already downloaded file"));
+    let mut buf = vec![0; 32768];
+    loop {
+        if let Ok(n) = downloaded.read(&mut buf) {
+            if n == 0 { break; }
+            hasher.input(&buf[..n]);
+        } else {
+            break;
+        }
+    }
+
+    Ok(hasher.result_str())
+}
+
 impl<'a> DownloadCfg<'a> {
 
     pub fn download(&self, url: &Url, hash: &str, notify_handler: &'a Fn(Notification)) -> Result<File> {
@@ -510,19 +527,7 @@ impl<'a> DownloadCfg<'a> {
         let target_file = self.download_dir.join(Path::new(hash));
 
         if target_file.exists() {
-            let mut hasher = Sha256::new();
-            use std::io::Read;
-            let mut downloaded = try!(fs::File::open(&target_file).chain_err(|| "opening already downloaded file"));
-            let mut buf = [0; 1024];
-            loop {
-                if let Ok(n) = downloaded.read(&mut buf) {
-                    if n == 0 { break; }
-                    hasher.input(&buf[..n]);
-                } else {
-                    break;
-                }
-            }
-            let cached_result = hasher.result_str();
+            let cached_result = try!(file_hash(&target_file));
             if hash == cached_result {
                 notify_handler(Notification::FileAlreadyDownloaded);
                 notify_handler(Notification::ChecksumValid(&url.to_string()));
@@ -543,7 +548,7 @@ impl<'a> DownloadCfg<'a> {
                 + ".partial");
 
         let mut hasher = Sha256::new();
-        
+
         try!(utils::download_file_with_resume(&url,
                                   &partial_file_path,
                                   Some(&mut hasher),