#Cache Testing
Reese,
Here's the first cut on my testing that we discussed last week. CD Speedway
does perform as advertised but less well than SpeedCache+, both of which
I've now tested, v1.01g for Speedway and v4.05 for SpeedCache+. Using an
8mb extended memory RAM drive for Speedway and an 8mb extended memory RAM
cache for Speedcache+, SpeedCache+ was noticeably smoother on playing
motion video once the movie clip had been loaded into the cache. In
addition, SpeedCache+ was loading the cache a bit faster than Speedway,
even though I was using the S:OFF parameter for Speedway. I attribute the
difference in playback smoothness to the fact that Speedway is doing file
I/O from the RAM drive whereas SpeedCache+ is operating directly from RAM
with no file I/O calls to the operating system.
My system is a 386-20, 16mb system RAM, 150 mb HD, ET-4000 video card,
running MS-DOS 5.0, Windows 3.1 and SuperStor 2.04. CD-Rom drive is a
Mitsumi CRMC-1000 which does meet the 150kb/sec MPC DTR spec. My setup is
fast enough so that it will play the Mammals movies fairly smoothly with no
cache at all; there are little occasional pauses but you have to look
closely to see them. SpeedCache+ will smooth those out very well. So will
Speedway, but the relatively long wait while it loads the next sequence
into the RAM drive is annoying. There are several such pauses during the
elephant movie, for example, but Speedcache+ will play the whole movie
through without any such pauses.
The rest of my testing was done in Windows, using an Aris MediaClips Jets
& Props CD disc set. The movie clips, which are MPC, and include sound, are
played through an Asymetrix Toolbook interface. Here again, playback from
cache was much smoother with Speedcache+, with only occasional pauses which
seem to be a shortcoming of ToolBook rather than anything to do with
caching. Speedway also improves over the no-cache situation, where DTR from
the CD causes lots of jerks, but even from Speedway's cache the pauses are
more frequent than with SpeedCache+, probably because of the extra overhead
of file I/O calls.
Tom
S1