RE: Does gzip support multiple processors under windows 2000?

["Robert Collins" <robert dot collins at itdomain dot com dot au>]

> -----Original Message-----
> From: Ilan Rabinovitch [mailto:Ilan.Rabinovitch@dig.com]
> Sent: Friday, March 23, 2001 9:02 AM
> To: cygwin@cygwin.com
> Subject: RE: Does gzip support multiple processors under windows 2000?
> 
> 
> 
> Chris,
> 
> I guess thats what Im trying to figure out.  Does it support it? 
> If not can anyone suggest a form a compression that would 
> work with multiple
> processors?
> 
> Thanks,
> Ilan

Most compression algorithms are single-threaded - there's few
opportunities for parallelism (every data bit out depends on the
immediately preceeding bits in). You could play tricks with maximum
compression lengths and reset the stream 50% through the file, then run
the 1st half through one compressor and the 2nd through another (that's
for 2 processors).. but I haven't heard of anyone doing that. (for the
most common uses og gzip it's kinda hard to know the file size to make
that work, and you can't seek stdin so you'd have to buffer internally).

In short I don't know of any parallel stream compressors. 

Your best bet is to start two operations side by side as parallel
processes - that will use both your cpu's.

Rob

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