diff --git a/AppKit/CPTextView/CPLayoutManager.j b/AppKit/CPTextView/CPLayoutManager.j
index 103e19921..6179243b9 100644
--- a/AppKit/CPTextView/CPLayoutManager.j
+++ b/AppKit/CPTextView/CPLayoutManager.j
@@ -1229,6 +1229,10 @@ var _objectsInRange = function(aList, aRange)
     }
 }
 
+// The spacings with kerning/ligatures are recalculated here for the visible part
+// See comment in layoutGlyphsInLayoutManager: of CPSimpleTypesetter
+// This gives an overall speed imrovement of ~20% in my testing (depending on text size / view size of course)
+
 - (CPArray)glyphFrames
 {
     if (!_exactFramesCalculated && _glyphsFrames && _runs && _runs.length > 0)
diff --git a/AppKit/CPTextView/CPTypesetter.j b/AppKit/CPTextView/CPTypesetter.j
index e8946fcfc..418bfbb4e 100644
--- a/AppKit/CPTextView/CPTypesetter.j
+++ b/AppKit/CPTextView/CPTypesetter.j
@@ -318,6 +318,9 @@ var CPSystemTypesetterFactory,
 
         var currentCharCode = theString.charCodeAt(glyphIndex),
             charStr = theString.charAt(glyphIndex),
+            // this is ignoring kerning and ligatures but 100x faster than calculating the full string
+            // we cut corners here and do the exact calculation in - glyphFrames of _CPLineFragment (CPLayoutManager.j)
+            // this gives an overall speed imrovement of ~20% in my testing (depending on text size / view size of course)
             charWidth = [charStr sizeWithFont:currentFont inWidth:NULL].width,
             rangeWidth = prevRangeWidth + charWidth;