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Date: Mon, 22 Dec 2008 22:20:26 -0800
From: Lawrence Mayer <lawmay3 AT i12 DOT com>
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Subject: Re: [1.7] Pipes intermittently lose data on Cygwin 1.7
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On 081222 19:02, Allan Schrum wrote:
> Would it be worth trying to heavily load one of your computers to see if the problem presents itself differently? It is obvious that your systems are fast!

Allan, at your suggestion, I repeated the trials on Computer 1 (details 
in previous post) under two opposite load conditions:

Condition 1: Maximum Load
All Cygwin trials performed during continuous run of Stress Prime 2004's 
Blend Test http://sp2004.fre3.com/ , a torture test which I use for 
stability testing when overclocking. The Blend Test stresses both CPU 
and RAM and keeps CPU usage at 100%.

Condition 2: Minimum Load
All Cygwin tests performed with minimum other apps running: just one DOS 
window (to run Cygwin tests) and one Explorer window (to keep track of 
bar's size).

Running a DOS window (cmd.exe) with Example 1 of my original post

	tr \32 \0 < foo | tr \0 \32 > bar

I ran 21 trials under each load condition with the following results:

Condition 1 (Maximum Load)
	foo = 5,138,895 bytes
	bar = 5,138,895 bytes (no error)	on 1 trial
	bar = 5,136,384 bytes (1254 x 4096)	on 6 trials
	bar = 5,132,288 bytes (1253 x 4096)	on 14 trials

Condition 2 (Minimum Load)
	foo = 5,138,895 bytes
	bar = 5,138,895 bytes (no error)	on 1 trial
	bar = 5,136,384 bytes (1254 x 4096)	on 2 trials
	bar = 5,132,288 bytes (1253 x 4096)	on 18 trials

As you can see, there was little difference in Cygwin's behavior under 
opposite load conditions. If anything, Cygwin did better under Condition 
1 (Maximum Load), but I don't think the difference is statistically 
significant.

Greetings,
Lawrence

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