Linux Today: Linux News On Internet Time.

SysAdmin: Which OS is Fastest -- FreeBSD Follow-Up

Jul 14, 2001, 12:01 (35 Talkback[s])
(Other stories by John Buckman, Jeffrey Rothman)

After running an OS shootout between Linux, FreeBSD, Windows 2000, and Solaris (in which Linux took top honors), SysAdmin got a shellacking of mail from "unhappy" FreeBSD advocates thanks to a configuration choice that didn't reflect the real world too well. New results are now in based on the appropriate tweak:

"After the FreeBSD tweaks, we found that FreeBSD tuned had very similar performance to Linux (untuned) when running 1000 or less simultaneous sends. Overall, the tuned version of FreeBSD was 27% faster at sending email than the untuned version. FreeBSD mail sending performance peaked at 1000 to 1500 simultaneous sends, and then steadily declined as simultaneous connections increased.

In the previously published test, we had been unable to run with 3000 connections. Now, with the 17 FreeBSD OS patches (including patches that our readers felt should fix this problem), we were frequently able to run at 3000 connections, but not much beyond that, and not consistently with 3000. In our program, the bind() system call failed sometimes with the EAGAIN error, other times with an EBADF error. This did not occur in the other operating systems. Both of these errors would indicate some sort of operating system resource shortage or system limit. Some of our readers wrote that they were aware of other FreeBSD sites that went well beyond these numbers of simultaneous connections, but none of the OS patches suggested allowed us to work around this limit. With overall mailing performance declining steadily, if mailing speed were the goal, it would not make sense to load FreeBSD with more than 1500 simultaneous sends.

For applications that are disk intensive, we recommend that systems administrators configure their FreeBSD system to use the async option (or use soft updates for more reliability). Our hard disk benchmark was 3.8 times faster with the asynchronous FreeBSD file system, and its performance was in line with Windows 2000 and Linux (slightly faster at times, and slightly slower at other times, depending on the file size). In our real-world MailEngine test, we found that a tuned version of FreeBSD was as fast as an untuned version of Linux, for connection levels of 1500 sends or fewer, with FreeBSD performance declining steadily at simultaneous connection levels above 1500."

Complete Story

Related Stories: