ArtemD said:Another things that shines through this benchmarks is UFS2's poor performance compared to ZFS and Ext3. I think UFS2+gjournal created with "-o time" option would yield a lot better results.
ArtemD said:Benchmarks were done using GENERIC kernel which as mentioned above is not optimized for speed. GENERIC kernel is optimized to run on as many hardware as possible and to be as stable as possible. This means it has no optimization tweaks and it's bloated with every possible driver that FreeBSD supports.
ArtemD said:Another things that shines through this benchmarks is UFS2's poor performance compared to ZFS and Ext3. I think UFS2+gjournal created with "-o time" option would yield a lot better results.
From "man newfs":Weinter said:Sorry i don't understand this part "-o time" option
Could you elaborate?
-o optimization
(space or time). The file system can either be instructed to try
to minimize the time spent allocating blocks, or to try to mini-
mize the space fragmentation on the disk. If the value of min-
free (see above) is less than 8%, the default is to optimize for
space; if the value of minfree is greater than or equal to 8%,
the default is to optimize for time. See tunefs(8) for more
details on how to set this option.
Weinter said:I think they didn't optimize Linux kernel or Solaris kernel as well so that point should be invalid
kamikaze said:Kernel debug does not slow the system down. The debug data is in separate files that only get loaded during debugging.
NOTE TO PEOPLE WHO THINK THAT FreeBSD 8.x IS SLOW:
FreeBSD 8.x has many debugging features turned on, in
both the kernel and userland. These features attempt to detect
incorrect use of system primitives, and encourage loud failure
through extra sanity checking and fail stop semantics. They
also substantially impact system performance. If you want to
do performance measurement, benchmarking, and optimization,
you'll want to turn them off. This includes various WITNESS-
related kernel options, INVARIANTS, malloc debugging flags
in userland, and various verbose features in the kernel. Many
developers choose to disable these features on build machines
to maximize performance. (To disable malloc debugging, run
ln -s aj /etc/malloc.conf.)
kamikaze said:Kernel debug does not slow the system down. The debug data is in separate files that only get loaded during debugging.
trasz@ said:Were the tests performed several times? Was the first run of each test discarded ('preheating')? What was the standard deviation? How can we tell if the measurement error is not bigger than the measured differences between systems? Without knowing that, the tests are not really relevant or useful.
ArtemD said:That is correct. I do think thou that placing too much value on this makes no sense since I assume most of FreeBSD users run custom kernels.
tomh009 said:Given how well the GENERIC kernel works, how many users will actually go through the work of building a custom kernel?