diff --git a/packages/fcl-stl/src/gdeque.pp b/packages/fcl-stl/src/gdeque.pp
index 5a50dc4cf1..037ba516c5 100644
--- a/packages/fcl-stl/src/gdeque.pp
+++ b/packages/fcl-stl/src/gdeque.pp
@@ -146,13 +146,29 @@ begin
 end;
 
 procedure TDeque.IncreaseCapacity;inline;
-var i,OldEnd:SizeUInt;
+const
+  // if size is small, multiply by 2;
+  // if size bigger but <256M, inc by 1/8*size;
+  // otherwise inc by 1/16*size
+  cSizeSmall = 1*1024*1024;
+  cSizeBig = 256*1024*1024;
+var
+  i,OldEnd,
+  DataSize:SizeUInt;
 begin
   OldEnd:=FCapacity;
-  if(FCapacity=0) then
-    FCapacity:=1
+  DataSize:=FCapacity*SizeOf(T);
+  if FCapacity=0 then
+    FCapacity:=4
   else
-    FCapacity:=FCapacity*2;
+  if DataSize<cSizeSmall then
+    FCapacity:=FCapacity*2
+  else
+  if DataSize<cSizeBig then
+    FCapacity:=FCapacity+FCapacity div 8
+  else
+    FCapacity:=FCapacity+FCapacity div 16;
+
   SetLength(FData, FCapacity);
   if (FStart>0) then 
     for i:=0 to FStart-1 do
diff --git a/packages/fcl-stl/src/gvector.pp b/packages/fcl-stl/src/gvector.pp
index 4035d2788a..0b58af79d1 100644
--- a/packages/fcl-stl/src/gvector.pp
+++ b/packages/fcl-stl/src/gvector.pp
@@ -157,11 +157,26 @@ begin
 end;
 
 procedure TVector.IncreaseCapacity();
+const
+  // if size is small, multiply by 2;
+  // if size bigger but <256M, inc by 1/8*size;
+  // otherwise inc by 1/16*size
+  cSizeSmall = 1*1024*1024;
+  cSizeBig = 256*1024*1024;
+var
+  DataSize:SizeUInt;
 begin
+  DataSize:=FCapacity*SizeOf(T);
   if FCapacity=0 then
-    FCapacity:=1
+    FCapacity:=4
   else
-    FCapacity:=FCapacity*2;
+  if DataSize<cSizeSmall then
+    FCapacity:=FCapacity*2
+  else
+  if DataSize<cSizeBig then
+    FCapacity:=FCapacity+FCapacity div 8
+  else
+    FCapacity:=FCapacity+FCapacity div 16;
   SetLength(FData, FCapacity);
 end;