diff --git a/client/components/Reader/share/bookManager.js b/client/components/Reader/share/bookManager.js
index 19659ffd..9d2932af 100644
--- a/client/components/Reader/share/bookManager.js
+++ b/client/components/Reader/share/bookManager.js
@@ -145,11 +145,13 @@ class BookManager {
 
 
     async deflateWithProgress(data, callback) {
-        const chunkSize = 16384;
-        const deflator = new utils.pako.Deflate({level: 9});
+        const chunkSize = 128*1024;
+        const deflator = new utils.pako.Deflate({level: 5});
 
         let chunkTotal = 1 + Math.floor(data.length/chunkSize);
         let chunkNum = 0;
+        let perc = 0;
+        let prevPerc = 0;
 
         for (var i = 0; i < data.length; i += chunkSize) {
             if ((i + chunkSize) >= data.length) {
@@ -158,8 +160,13 @@ class BookManager {
                 deflator.push(data.substring(i, i + chunkSize), false);
             }
             chunkNum++;
-            callback(Math.round(chunkNum/chunkTotal*100));
-            await utils.sleep(1);
+
+            perc = Math.round(chunkNum/chunkTotal*100);
+            if (perc != prevPerc) {
+                callback(perc);
+                await utils.sleep(1);
+                prevPerc = perc;
+            }
         }
 
         if (deflator.err) {
diff --git a/client/components/Reader/versionHistory.js b/client/components/Reader/versionHistory.js
index 14bf8fa6..795b2786 100644
--- a/client/components/Reader/versionHistory.js
+++ b/client/components/Reader/versionHistory.js
@@ -1,7 +1,7 @@
 export const versionHistory = [
 {
     showUntil: '2019-06-22',
-    header: '0.6.8 (2019-06-23)',
+    header: '0.6.9 (2019-06-23)',
     content:
 `
 <ul>
@@ -10,7 +10,7 @@ export const versionHistory = [
     <li>добавлены новые варианты анимации перелистывания</li>
     <li>на страницу загрузки добавлен блок "Поделиться"</li>
     <li>улучшены прогрессбары</li>
-    <li>исправления недочетов</li>
+    <li>исправления недочетов, небольшие оптимизации</li>
 </ul>
 `
 },