Would Sage benefit from multi-core, multi cpu configurations?

[kamikaze2112]

Just as the title says, would you notice a big performance boost running sage on a dual quad core xeon system, say for arguments sake, 2.5ghz xeons on an Asus workstation/server board with something like 4 or 8 gb of ram?

I"ll be running 2 hauppauge pvr 150's, and the possibility of 2 HD-PVR's as well, and will be streaming to MediaMVP's (both SD and HD).

Or am I better off building a single CPU system, likely with a 3+ghz quad core xeon or core-quad duo (or whatever they are called these days)? WIll sage take full advantage of that many cores. Keep in mind that this machine will be strictly a media server, for sagetv and storing other media (ripped dvd's, music, etc)

[Brent]

I would do a dual-core at least(probably quad-core) for the server. Its not required, but will definitely help you out with these things:

• any transcoding (MVP with HD)
• HD-PVR playback requires at least dual-core if you are using this for playback.
• commercial detection of h.264 files (HD-PVR) are very CPU intensive and you'll be much happier if you choose quad-core with more power.

[kamikaze2112]

Originally Posted by Brent

I would do a dual-core at least(probably quad-core) for the server. Its not required, but will definitely help you out with these things:

• any transcoding (MVP with HD)
• HD-PVR playback requires at least dual-core if you are using this for playback.
• commercial detection of h.264 files (HD-PVR) are very CPU intensive and you'll be much happier if you choose quad-core with more power.

See, it's for that CPU intensive stuff, I'd wonder if going with dual quad cores would be faster then a single quad core at a higher clock rate.

Also, not quite sure why this was moved, as I was trying to gauge opinion rather than solve a particular problem, which is why I put it in general discussion to begin with.

[GKusnick]

I believe all those tasks (transcoding, decoding, commercial detection) are sequential, single-threaded tasks. So more CPU cores probably won't speed up any individual task, since they're not set up to divide the load that way. (Comskip experts, feel free to correct me if I'm wrong here.)

Multiple cores will help make multiple simultaneous tasks run faster. So if you're transcoding for several clients at the same time, more cores might be a good idea. But my gut feeling is that an eight-core system is probably overkill (unless you're just looking for an excuse to spend money).

[Brent]

Seems like quad core should be more than enough.

[gilded07]

I'm assuming that SageTV v6 is not optimized for multi-cores. Has there been any indication from Sage if they will be considering this in a future upgrade to v6 or with v7?

My single core P4 is more than adequate for playing .avi movies and recording / watching SD TV with comskip. But since all new CPUs are multi-core now it seems like it would make sense for future versions of SageTV to be optimized to take advantage of this extra processing power.

[Sam]

Originally Posted by gilded07

I'm assuming that SageTV v6 is not optimized for multi-cores. Has there been any indication from Sage if they will be considering this in a future upgrade to v6 or with v7?

I can't speak to SageTV server directly, but where you benefit from multiple cores is in transcoding and commercial detection. Use HD100's and you minimize the need for transcoding (compared to the MVP). Placeshifter still needs transcoding though. Since ffmpeg can use multiple cores, I assume Sage can as well.

Commercial detection is done by third party apps, so whether Sage itself can utilize additional cores or not may not be a major factor. Maybe it is when you have enough concurrent users or tuners active.

I'd be more likely to go with a faster quad-core than a slower eight-core, but that's just me.

[mickp]

I agree that multiple cores will definitely help. Going dual quad core xeon (8 cores) is probably overkill though

Mick.

[davephan]

A dual-core CPU really helps with video transcoding compared to a single core CPU. I don't know how much more performance would be gained by a quad-core. If I were buying today, with the lower prices, I would go with a 3.0 gig quad core.

If you want even more cores, can wait awhile, and pay premium prices, you could go with a six core CPU!

http://www.engadget.com/2008/02/25/i...u-info-leaked/

Dave

[bcjenkins]

SageTV will run transcode processes on separate threads. Depending on how many simultaneous shows you watch on MVPs (transcode)/comskip scans/whatever else you may throw into the mix should drive your decision.

B

PS - Take a look at the processor requirements for comskip/SA on hdpvr files.

[reggie14]

Originally Posted by bcjenkins

SageTV will run transcode processes on separate threads. Depending on how many simultaneous shows you watch on MVPs (transcode)/comskip scans/whatever else you may throw into the mix should drive your decision.

Right, but one transcoding process will not split off into multiple threads. In general it often doesn't really matter, since most dual/quad core processors are fast enough that one core can do the job on it's own (e.g. for transcoding HD for the MVP). But, it does mean video conversions in Sage are slow. Also, without a multithreaded transcoder we'll probably never see transcoding H.264 files from the HD-PVR to the MVP.