Changes between Version 2 and Version 3 of Performance

Timestamp:

Feb 17, 2011, 7:04:03 PM (15 years ago)

Author:

goddard

Comment:

--

Performance

@@ -1 +1 @@
 == Chimera Speed and Memory Use ==
+
+What causes Chimera to run slowly or run out of memory?
 
  * [#GraphicsSpeed Graphics speed]
@@ -5 +7 @@
  * [#MemoryRequirements Memory requirements]
  * [#bit64 32-bit versus 64-bit Chimera binaries]
- * Multi-core calculations
+ * [#multicore Multi-core calculations]
 
 == Graphics Speed ==
 
-Why is rotating the scene slow?
+Why is rotating the scene slow?  Large molecules or volume data can cause display updating
+slower than the normal 30 frames per second.
 
- * Graphics card speed
- * Selected objects
- * Transparency
+'''Graphics card.'''
+Drawing speed is usually limited by the speed of the graphics card.
+See the table of [wiki:benchmarks benchmark results] for different graphics cards running Chimera.
+Chimera uses OpenGL for 3-dimensional graphics.  A card that is fast for playing video games is likely
+to be fast for Chimera.  Integrated Intel graphics in laptops and desktops is usually slowest.
+Graphics cards from Nvidia and ATI are common and work well.
+On Linux installing a graphics driver is usually necessary.  If Chimera menu entry Help / Report a Bug
+lists the OpenGL renderer as '''Mesa''' in the ''Gathered Information'' section then you need to install
+a graphics driver.
+
+'''Selected objects'''
+The green outline around selected objects is created by drawing the selected objects 5 times.
+If everything is selected than the rendering can be 5 times slower.
+
+'''Transparency'''
+Rotating large transparent surfaces can be slow.  For each orientation the triangles making up the
+surface are sorted by depth and drawn in order from farthest away to nearest.  The sorting is done
+on the CPU, not the graphics card.  The time to do the sorting each time the scene is redrawn often
+limits the frame rate.
+
+'''Molecule display styles'''
+Displaying all atoms of a large molecule (e.g. 100,000 atoms) can cause slow rendering.
+The ''wire'' display style is fastest, while ''stick'', ''ball and stick'', and ''sphere''
+display styles are typically a 10 to 100 times slower.  Showing only the backbone of a protein
+using ''ribbon'' style is faster than showing all atoms (except for ''wire'').  The Chimera
+'''subdivision quality''' setting controls the smoothness of these molecule depictions and
+higher values will cause slower display.
+
 
 == Calculation Speed ==
@@ -19 +47 @@
 == Memory Requirements ==
 
-[=#bit64]
-== 32-bit versus 64-bit Chimera binaries ==
+== 32-bit versus 64-bit Chimera binaries == #bit64
 
-== Multi-core Calculations ==
+== Multi-core Calculations == #multicore