TIFF performance: overviews and internal tiles: Surprise!

[Gregor Mosheh]

Ed McNierney wrote:
> Could you go into a bit more detail about your 4-disk RAID-5 system?
 > What kind of controller?  What capacity, interface, and rotation 
speed are the
 > disks?

3Ware 9550X controller.
Four disks, no hotspare: 4 spindles at work.
Western Digital, SATA-2, 7500 rpm, 500 GB apiece.

I am quite surprised by the lack of performance increase even in a 2 GB 
file, due to overviews and/or tiling.

My only supposition is that the RAID is so fast that these performance 
enhancers don't make a difference, and I say that with tongue in cheek. 
I'll grab MS4W and repeat the experiment on my single-core single-disk 
Pentium-4 desktop machine.

-- 
Gregor Mosheh / Greg Allensworth
System Administrator, HostGIS cartographic development & hosting services
http://www.HostGIS.com/

"Remember that no one cares if you can back up,
  only if you can restore." - AMANDA