fsjcb1@acad3.alaska.edu (Curt Beavers) (02/14/91)
I'm looking for some information on what may be causing a serious speed
problem in communications under Windows. I'm running a Micronics 486/25 with
an internal 2400 baud modem, and if I use Telix, a dos app, through Windows
with no other apps running, I get jerks when my screen is updating. Windows
will write out half a line, pause for half a second, and then continue writing.
This isn't the occasional pause, but a pause about every line.
At first I thought it was the speed decrease from having my pifs set wrong
& my timeslice set too high, but I tried all the combinations I could & nothing
seemed to help. Then I thought maybe it was using a dos comm program that was
the problem, so I tried Windows Terminal and WinQVT and experienced the same
problems. Running only WinQVT with no dos apps and no other windows app other
than program manager running, I still experienced the same jerkiness.
Then, I thought I'd try and figure out what was going on, so I installed
CPUUSE & CPUGRAPH (the program that graphs processor use on its icon?).
Running these two things, clock, program manager, & Telix showed me idling at
around 40% CPU use. Once I started using my comm program, that went up to 50%
and when a full screen update was taking place it would jumpy to 70%, and
sometimes even reach into the 90% range!
Now running a 486/25 rated at 11.4 Vax 11/780 MIPS, that tells me that
windows is using 20% of 11.4 or over 2 Vax MIPS to write data coming in over
COM 2 at 2400 baud? Something smells in Denmark here folks! What's up?
Possible solutions...Windows 3.1 may or may not address this extremely annoying
problem. Get an advanced UART chip with a 16 bit buffer? I've heard this may
not work through Windows. So what's left? Am I missing something fundamental
in my Windows setup here? I really can't see Microsoft using so much overhead
that a 486/25 is slower than my Apple ][c.
Extremely confused in Fairbanks,
--
Curt Beavers
Microcomputer Technician
University of Alaska -- Fairbanks
FSJCB1@Acad3.Alaska.Eduergo@netcom.COM (Isaac Rabinovitch) (02/15/91)
I've had some of the same trouble with various DOS programs that do a
lot of I/O. I think the basic problem is that they always look "busy"
to Windows, when all they're doing is waiting for the last input or
output to finish -- so they end up being allocated a bigger share of
the CPU than they need.
Even if my explanation is bogus, my solution seems to work: lower the
priority of the DOS program. This is one of the "advanced" options in
the PIF file.
--
ergo@netcom.com Isaac Rabinovitch
netcom!ergo@apple.com Silicon Valley, CA
{apple,amdahl,claris}!netcom!ergo
(specific statement withheld at this time for operational reasons)