Romano wrote:  Yesterday I compiled latest lzlib 1.9 and plzip 1.7 under 
cygwin(also  latest, just installed yesterday) on Windows 7 and as a 64bit 
both. It  compiled without any errors or warning and tool also work fine. 
During  packing it is able to utilize all CPU cores to 100% so multi threading  
works. Same with testing using -t flag. However, when I actually try to  unpack 
with -d it never even peak above 50%. This despite -n option,  even if I double 
the number to -n 8. On parallel, until now I always  used FreeArc's 
internal 4x4:lzma which always fully utilized my cpu and  it shows as during 
unpacking without io limitation it could reach  ~200Mib/s.   I don't use 
Windows, so I can't test your executable. (BTW, please,  don't spam the 
list with huge unsolicited files). The fact that plzip  can use all cores while 
testing makes me suspect of some I/O  problem/idiosyncrasy. See for example 
this thread on the MinGW list:    I am aware 
of blocks concept as well, tool also did not utilized all CPU  with smaller -B 
block and big enough file, and I know for sure its not  my HDD limiting it 
because first it is quicker than output and FreeArc  can still utilize its max, 
but also because it does not utilize full CPU  even if using stdin/stdout.   
Even if decompressing from a regular file to /dev/null ?   Yes - it seems 
/dev/null is treated as you said as non seekable - I noticed the same on linux 
decompressing to null device, you can check yourself. I was actually to report 
the very same thing and made some test with some big amount of data only to 
find out it's intended behaviour. But not all in vein - it turned out that 
decompressing to standard file removes limitations.
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