Data Point: File handling on Windows

Hi there,

Last week on IRC I had a short discussion with Bert about
the file handling overhead on Windows. That prompted me
to run some tests on my notebook and this is what I found.

Opening or creating files and folders is not too expensive
even on NTFS. Creating and deleting folders is about as
expensive as creating or deleting empty files. Gains from
using multiple worker threads are measurable but scalability
is limited - at least as long as we operate on the same volume.
And even on Windows, c/o speeds >2000 files / sec are
technically feasible.

All tests are being executed repeatedly for 100 different
files in a single folder, no virus scanner active, 2 core
2.4GHz CPU; Windows XP 32 bits.

Results in detail shown as runs per second:

Test\#Threads 1 2 gain
(1) 5,639 6,798 21%
(2) 9,663 11,818 22%
(3) 3,943 5,292 34%
(4) 4,461 6,331 42%
(5) 4,460 5,842 31%
(6) 6,936 7,272 5%
(7) 8,305 9,661 16%

(1) ... create and close empty files
(2) ... delete these empty files
(3) ... create, write 12kB and close files
(4) ... rename these files
(5) ... delete these files
(6) ... create empty directories
(7) ... delete these empty directories

Test (1) with varying number of files per folder, 1 thread:
10 6,307
100 5,639
1000 5,083
10000 4,319

-- Stefan^2.
Received on 2011-04-27 00:31:28 CEST