diff --git a/src/apps/activitymonitor/ActivityView.cpp b/src/apps/activitymonitor/ActivityView.cpp
index a4e1ee2b0e..5fea2cd6b4 100644
--- a/src/apps/activitymonitor/ActivityView.cpp
+++ b/src/apps/activitymonitor/ActivityView.cpp
@@ -553,7 +553,7 @@ const float kDraggerSize = 7;
 ActivityView::ActivityView(BRect frame, const char* name,
 		const BMessage* settings, uint32 resizingMode)
 	: BView(frame, name, resizingMode,
-		B_WILL_DRAW | B_SUBPIXEL_PRECISE | B_FULL_UPDATE_ON_RESIZE | B_FRAME_EVENTS),
+		B_WILL_DRAW | B_FULL_UPDATE_ON_RESIZE | B_FRAME_EVENTS),
 	fSourcesLock("data sources")
 {
 	_Init(settings);
@@ -598,6 +598,7 @@ ActivityView::ActivityView(BMessage* archive)
 
 ActivityView::~ActivityView()
 {
+	delete fOffscreen;
 	delete fSystemInfoHandler;
 }
 
@@ -608,6 +609,7 @@ ActivityView::_Init(const BMessage* settings)
 	fHistoryBackgroundColor = (rgb_color){255, 255, 240};
 	fLegendBackgroundColor = LowColor();
 		// the low color is restored by the BView unarchiving
+	fOffscreen = NULL;
 #ifdef __HAIKU__
 	fHistoryLayoutItem = NULL;
 	fLegendLayoutItem = NULL;
@@ -924,6 +926,51 @@ ActivityView::MinSize()
 #endif
 
 
+void
+ActivityView::FrameResized(float /*width*/, float /*height*/)
+{
+	_UpdateOffscreenBitmap();
+}
+
+
+void
+ActivityView::_UpdateOffscreenBitmap()
+{
+	BRect frame = _HistoryFrame();
+	frame.OffsetTo(B_ORIGIN);
+
+	if (fOffscreen != NULL && frame == fOffscreen->Bounds())
+		return;
+
+	delete fOffscreen;
+
+	// create offscreen bitmap
+
+	fOffscreen = new(std::nothrow) BBitmap(frame, B_BITMAP_ACCEPTS_VIEWS,
+		B_RGB32);
+	if (fOffscreen == NULL || fOffscreen->InitCheck() != B_OK) {
+		delete fOffscreen;
+		fOffscreen = NULL;
+		return;
+	}
+
+	BView* view = new BView(frame, NULL, B_FOLLOW_NONE, B_SUBPIXEL_PRECISE);
+	view->SetViewColor(fHistoryBackgroundColor);
+	view->SetLowColor(view->ViewColor());
+	fOffscreen->AddChild(view);
+}
+
+
+BView*
+ActivityView::_OffscreenView()
+{
+	if (fOffscreen == NULL)
+		return NULL;
+
+	return fOffscreen->ChildAt(0);
+}
+
+
 void
 ActivityView::MouseDown(BPoint where)
 {
@@ -1279,7 +1326,13 @@ ActivityView::_PositionForValue(DataSource* source, DataHistory* values,
 void
 ActivityView::_DrawHistory()
 {
+	_UpdateOffscreenBitmap();
+
 	BView* view = this;
+	if (fOffscreen != NULL) {
+		fOffscreen->Lock();
+		view = _OffscreenView();
+	}
 
 	BRect frame = _HistoryFrame();
 	BRect outerFrame = frame.InsetByCopy(-2, -2);
@@ -1378,9 +1431,12 @@ ActivityView::_DrawHistory()
 		view->EndLineArray();
 	}
 
-	view->SetPenSize(1);
-
 	// TODO: add marks when an app started or quit
+	view->Sync();
+	if (fOffscreen != NULL) {
+		fOffscreen->Unlock();
+		DrawBitmap(fOffscreen, outerFrame.LeftTop());
+	}
 }
 
 
diff --git a/src/apps/activitymonitor/ActivityView.h b/src/apps/activitymonitor/ActivityView.h
index 82ed245d24..9983f1f323 100644
--- a/src/apps/activitymonitor/ActivityView.h
+++ b/src/apps/activitymonitor/ActivityView.h
@@ -86,6 +86,7 @@ protected:
 	virtual	BSize		MinSize();
 #endif
 
+	virtual void		FrameResized(float width, float height);
 	virtual void		MouseDown(BPoint where);
 	virtual void		MouseUp(BPoint where);
 	virtual void		MouseMoved(BPoint where, uint32 transit,
@@ -100,6 +101,8 @@ private:
 			::Scale*	_ScaleFor(scale_type type);
 			void		_Refresh();
 	static	status_t	_RefreshThread(void* self);
+			void		_UpdateOffscreenBitmap();
+			BView*		_OffscreenView();
 			void		_UpdateFrame();
 			BRect		_HistoryFrame() const;
 			float		_LegendHeight() const;
@@ -121,6 +124,7 @@ private:
 
 	rgb_color			fHistoryBackgroundColor;
 	rgb_color			fLegendBackgroundColor;
+	BBitmap*			fOffscreen;
 #ifdef __HAIKU__
 	BLayoutItem*		fHistoryLayoutItem;
 	BLayoutItem*		fLegendLayoutItem;