Horsepower needed for HDPVR -> Media MVP transcoding
 

Hello,

I've been searching the forums but haven't been able to find an updated answer since Sage added multi-core support to the transcoder and Sage 6.5.1 beta added:
"27. HDPVR transcoding should now function correctly in SageTVTranscoder"

Has anyone been able to successfully transcode HDPVR recordings to their MVP Extenders on the fly? If so, what kind of CPU was used?

My server built out of orphaned spare parts is starting to show it's age, and I'm thinking it's time to upgrade but would like the ability to trascode the h264 files to my 2 older mvps.

Any help would be greatly appreciated.

Thanks in advance.

Multi-threading transcoder - :clap:

There's hope yet. I too run my Sage server on older hardware, as it hasn't needed any horsepower. At least not until I picked up an HDHomeRun, and tried to watch it on my MVP. Since the multi-threading was added in v6.5.2 Beta, I've yet to see if it'll help my dual P3 1.4Ghz server. I'm still holding out for v6.5 final release, soon I hope...

I was very excited about multi-threading with the transcoder, but have been very disappointed with the performance. Before it would max out 1 core (50% cpu usage in task manager). Now the load is spread more evenly between the 2 cores, but total cpu usage still never goes above 50% according to task manager.

It's better than before, but still not what I was hoping for.

Is this still the case with the newest beta? The release notes said they made some changes to the transcoder that improved performance.

It really seems like it should parallelize very well.

Yes, that's with 6.5.6. This is the only release where multi-threading has worked at all for me.

Interesting question here.... if the channel is provided by a sagetv server running as a network encoder; does the network encoder do the transcoding or the central (main) sagetv server? It would be sweet if we could parallelize it across servers!

My 'new' server is still not able to do h.264 to a MVP. fyi an FX-62 is about the fastest dual core AMD processor. So I am thinking you would need a quad-core?

Given user reports on the multi-threaded transcoder, I don't think a quad core would help. You would need a faster CPU. Intel processors tend to be much faster clock-for-clock at video encoding.

Forgive me if I'm misinterpreting the OP's question here (which I may very well be). As I understand it, you are trying to watch an HD-PVR recording directly on your MediaMVP (not previously transcoded), correct?

If that's not the case, I apologize. If it is, I've been doing this for some time (i.e. watching "live" TV on a wired Media MVP, originally HD content, recorded with an HD-PVR). I recently had some stuttering, but I think that's an issue with the beta, b/c it worked fine before I got my HD200s and had to install the beta.

Anyway, my Sage server is a quad-core 6600 with 4 GB RAM (32-bit Windows, so 3GB RAM effectively). For what it's worth, during one bowl game a couple weeks ago, I had the same file recording and playing back on 1) the server, 2) and an HD-200 and 3) transcoding and playing back on a MediaMVP at the same time.

Quad Core it is
 

Thanks toddyus!:goodjob:

That was the exact answer I was looking for. So it looks like if I want to transcode to my MVP I need to start looking into a hefty CPU.

Thanks to everyone for all your input.

No problem.

For what it's worth, I don't know what kind of server you're running now, but if it's going to cost you more than 2 hundred bucks to upgrade it, I would forego the upgrade (assuming it's working well for everything else), and replace the MediaMVP with an HD200. Far better results with the new device... That's what I'm hoping to do shortly with my last remaining MVP.

Indeed, I would certainly go for the HD200 (did it this month). It does not only 'solve' the transcoding issue and high server requirements, it also - in my case at least - had a major usebility improvement. I have a various set of media types, and most just play native on the HD200. The transcoding did for some also mess up the picture (losing part of it), now all that is gone.

So for 200$, compared to investing in server power :rolleyes:

Originally Posted by enzominator
My 'new' server is still not able to do h.264 to a MVP. fyi an FX-62 is about the fastest dual core AMD processor. So I am thinking you would need a quad-core?

So does a quad core, rather than a dual core, not help in the multi-threaded transcoding because it only takes advantage of two cores instead of the four that are available? Because one would think that quad core should be faster than dual core, all other things being equal of course.

Quadcores are only faster that dual cores when and if the multi-threading truly allows for it. It seems based on early results (but nothing truly difinitive) that the Sage transcoder while somewhat multi-threaded, it is not fully multi-threaded (in that it appears to spread the transcoding across multiple cores but still only uses 50% overall processing on dual cores and 25% for quads).

I just noticed in Sage's V6.5.6 release notes, under 'Core updates', the following: "Properly enabled multi-threading in the transcoders now (it won't max out all the cores; but it'll make much better use of them than it did before)"

I wonder why they didn't 'max out all the cores'? Just not high on the priority list or some other limitation?

I am deciding on CPU's right now for my first SageTV system (running on a headless HTPC with a HD ATSC tuner and one or two HD-PVRs, so there will be quite a bit of H.265 transcoding) and compared a popular dual core processor with a quad core one. The dual core Intel E8400 (3 GHz, 6M cache) is about $165, whereas the quad core Intel Q6700 (2.4 GHz, 8M cache) is about $275, both of which run on the same type of motherboard and DDR2 memory.

So, in the entire scheme of things, this adds about 10-15% to the cost of the HTPC. But, if the transcoder and comskip won't take advantage of all of the cores, then the investment in extra processing power will only be worthwhile when and if the extra cores can be taken advantage of.

There's no simple answer which is better. But, when it comes to transcoding, you should assume it will only go as fast as one of your cores. That might not be a problem, depending on what you want to do. But, if you want to transcode HD-PVR files to an MVP on-the-fly, you might be better off with the faster dual core. I don't have an HD-PVR, so I can't tell you how fast your processor has to be to transcode those files in real-time. toddyus's experiences suggest a Core2 2.4 GHz is fast enough for that, but it might be in the gray area.

For comskip, I think the choice is clearly in favor of a quad core. Of course, comskip isn't necessarily something that needs to be done in real-time, although it's sort of nice if it does. I'm only guessing, but I think a dual core Core2 3.0Ghz should be fast enough to run comskip on an HD-PVR recording in near real-time, but you'd have to find the comskip thread to be sure. If it is, then the quad core's advantage is really in doing multiple things at once.

Just one quick correction: I'm running a quad-core 2.4 GHz, not a dual-core.

Either way though, I still feel it's a gray area. My quad-core machine became the new server when the old server bit the dust. I also already had the MediaMVP. It's logical for me to use the MediaMVP, but it doesn't always run smoothly, especially when the server's doing other stuff. As a matter of science, yes it's possible to run this setup. As a matter of practice, however, it's imperfect.

If you need the transcoding mainly to feed other client displays, you're better off saving the money on the server chip and buying HD200s for the clients. They run flawlessly. I don't know about you, but "flawless" in my house makes me a happily married man...