cpu frequency scaling for video editing machines

[Ralf Mardorf]

On Sat, 2011-06-18 at 23:29 +0000, Luke Kuhn wrote:
> For video editing (and for 3d content creation as well) a different
> issue arises: The need to minimize excess power consumption when not
> rendering or playing the timeline. Video editing is often done on very
> powerful 4 core or even 6 core computers, and these are power hogs,
> with CPU power dissipation alone sometimes as high as 140 watts. 
> 
> 
> Although running full speed at idle doesn't mean anywhere near the
> same heat as full load, it can be enough to make the fan noise come
> up, and in some cases the rooms these machines are used in can become
> uncomfortably hot-I know mine does! The last thing I want to do is use
> more electricity first to fun full voltage and multiplier all the
> time, and make the room even hotter in the process.
> 
> 
> These machines benefit greatly from using all the power-saving tricks
> during what can be a multi-hour editing session prior to rendering,
> yet being able to throttle up when the timeline is played in something
> like Kdenlive.
> 
> 
> This is not the sort of thing I have any trouble working on and
> setting up as I like, but again we come back to the issue of a new
> user. If someone sets up a video editing workstation with any distro,
> finding high temps and the fans running hard compared to what they did
> in Windows is a real turnoff, similar to complaints about open-source
> video drivers on big video cards that by default have to turn off
> frequency scaling, again due to performance issues.
> 
> 
> Perhaps the installation GUI could ask an installer what the
> predominant use of their machine is to be, and recommend a setting for
> CPU frequency scaling, with an "advanced" option to override?

For this example a user will notice that the machine should have less
load, while for 'ondemand' on an audio machine the user has no idea that
CPU frequency scaling could be the cause for glitches, because e.g. a 4
or 6 core 'ondemand' still will run with much more GHz, than an old PC a
user used for audio production. Especially users hat switch from Windwos
to Linux will be puzzled, because Windows is much less resource hungry
for DAWs.
Another issue is that Linux provides professional audio apps, but no
professional video apps, hence IMO audio is much more important.

IMO it doesn't need a special multimedia distro for hobby usage, such as
video editing with Linux, or even for professional artwork, e.g. with
GIMP.

In would welcome if multimedia distros provide everything that's needed
for professional work flow, since Linux can't provide this for video
editing, IMO audio is much more important. A lot of gfx card vendors
take care of Linux, while most professional audio cards can't be used
with Linux. This is regarding to the 'toy' approach of Linux multimedia,
because especially flashy desktop toy computers need fast gfx cards.
For a professional audio tool we need professional audio cards, but
since most people have issues to set up a working audio Linux, most
people aren't using Linux for audio, so audio card vendors don't spend
time to support their cards for Linux.

For professional usage of graphic apps, nobody needs a multimedia
distro, because GIMP and other apps will work OOTB with any regular
distro.

People who which to do hobby video editing can spend some time to set up
their video editing machine, professional audio studios can't spend time
too set up a tool. Yes, universities are an exception, they have some
privileges a commercial audio studio hasn't.

Regarding to workflow issues no famous audio studio will switch to
Linux, but at least many semi-professional studios and some non-famous
professional studios could switch to Linux.

If a multimedia distro doesn't take care about this, than IMO there's no
need for multimedia distros, since Linux with issues, regarding to
audio, is provided by every regular major distro.

OT: Robin Gareus added frame-accurate video-timeline to Ardour3, see
http://rg42.org/wiki/a3vtl , since coders will enable professional NLE,
we have to wait some years.