unzip parallel, 3x faster than 7zip

[Jay Norwood]

>
> I think he is talking about 7zip the standalone software, not 
> 7zip the compression algorithm.
>
>> 7zip took 55 secs _on the same file_.

Yes, that's right, both 7zip and this uzp program are using the 
same deflate standard format of zip for this test.  It is the 
only expand format that is supported in std.zip.   7zip was used 
to create the zip file used in the test.

7zip already has multi-core compression capability, but no 
multi-core uncompress.  I haven't seen any multi-core uncompress 
for deflate format, but I did see one for bzip2 named pbzip2.  In 
general, though, inflate/deflate are the fastest algorithms I've 
seen, when comparing the ones that are available in 7zip.   I'm 
happy with the 7zip performance on compress with the inflate 
format, but not on the uncompress, so I will be using this uzp 
app.


I'm curious why win7 is such a dog when removing directories.  I 
see a lot of disk read activity going on which seems to dominate 
the delete time. This doesn't make any sense to me unless there 
is some file caching being triggered  on files being deleted. I 
don't see any virus checker app being triggered ... it all seems 
to be system read activity.  Maybe I'll try non cached flags, 
write truncate to 0 length before deleting and see if that 
results in faster execution when the files are deleted...