Gentoo Archives: gentoo-amd64

From: Peter Humphrey <prh@××××××××××.uk>
To: gentoo-amd64@l.g.o
Subject: [gentoo-amd64] Choice of processor timer frequency?
Date: Fri, 18 May 2007 10:30:10
Message-Id: 200705181126.48654.prh@gotadsl.co.uk
1 It's just occurred to me to question this kernel configuration option, which
2 is under Processor Type and Features.
3
4 We used to have to choose from 100, 250 and 1000 Hz, but recently 300 Hz has
5 been added, with the following Help text:
6
7 ----
8 CONFIG_HZ_300:
9 300 Hz is a good compromise choice allowing server performance while also
10 showing good interactive responsiveness even on SMP and NUMA systems and
11 exactly dividing by both PAL and NTSC frame rates for video and multimedia
12 work.
13 ----
14
15 At first I followed the advice without thought, but on reflection it occurs
16 to me to wonder about the truth of this statement. I suspect it's only true
17 in North America, northern Japan and a few other places, where the public
18 supply frequency is 60 Hz. In the rest of the world, with its 50 Hz, I
19 think 250 would be a better choice.
20
21 I also think it would be more accurate to say "dividing exactly into"
22 than "by".
23
24 Would anyone like to comment?
25
26 --
27 Rgds
28 Peter Humphrey
29 Linux Counter 5290, Aug 93
30 --
31 gentoo-amd64@g.o mailing list

Replies