Hardware, specifically sound

[slick_rick]

I'm thinking of putting together a Linux HTPC with XBMC. I'm guessing for video I want something NVidia, but I'm curious about sound. I've got a 7.1 sound setup and I'm hoping that XBMC will output an digital audio stream to drive as many of those channels as the source has. Curious if my old SBLive (emu10k) chipset would work or possibly a MB with the spidf stuff built in...

So will XBMC do digital out in 5(or 6 or 7).1? If so can anyone recommend a good MB with spidf out (hopefully optical) and NVidia onboard?

[rodalpho]

Yes, XBMC will do 7.1 passthrough. I've had good luck with my nvidia 630i uATX motherboard from EVGA, model number is "112-CK-NF77-A1". I use onboard video and sound. It has coax and optical SP/DIF, HDMI, (but HDMI audio doesn't work on linux) and DVI built-in. I have no problems playing 1080p with an e4500 at 2.93Ghz.

[BLKMGK]

The one thing to be aware of is that some CODECS have bandwidth requirements that SPID/F cannot meet. I get 5.1 just fine, THX, Dolby Digital, are what I'm getting...

[althekiller]

SPDI/F can handle all of the codecs that XBMC can handle just fine.

[jkrellner]

I, too, am planning on building a custom-designed HTPC with Linux (Ubuntu) for XBMC, as soon as the funds become available. The motherboard recommended here sounds good as it has onboard sound and video. With respect to Ubuntu, however, how do you get to the detailed display setting without having to modify xorg.conf?? I tried hooking up the PC I am using to play with XBMC (pretty great machine that used to run Windows XP, but sucks for Linux/XBMC because it has an ATI Radeon card and no digital sound) to my 1080p projector using a DVI-to-HDMI cord and got no picture -- the TV (JVC-RS1) said the "frequency" was "out of range." I figure I have to tweak the refresh rate or something to get this working.

In the future, does Team XBMC have plans to post required/recommended specs? For example, I plan to play a lot of 1080i content and presumably 1080p, and would like to be ready for 7.1 even if most of the stuff I play now is 5.1. If possible, I'd like to use the motherboard, processor and RAM from my XP machine and maybe add on a soundcard and swap out the vidcard. I just do not want to drop down the $$$ now only to find out I should have bought X, Y and Z which would have been so much better.

Thanks all. I am still in the phase where it feels "weird" to be using XBMC off the Xbox, but it is a weirdness I love and I cannot wait to deploy it in my theater.

[rodalpho]

8.04 does have some display config stuff in it but you'll have better luck asking about that in the very helpful ubuntu forums than here.

The devs do not have an official recommended config yet; they do have a minimum config which is basically ubuntu and a graphics card capable of opengl2.0 or a GMA950.

[jkrellner]

OK, I have a handful of hardware-related questions (if answers are even known at this point):

1. Will having two graphics cards in an SLI setup help HD performance at all?

2. Will 4GB of RAM help speed anything up, as compared to 2GB?

3. Which is more important, CPU speed or GPU speed?

4. It seems like dual core will help; would quad-core be overkill?

5. Lastly, in lieu of a hard drive, I am contemplating running Linux/XBMC from a USB stick; would performance take a hit in doing so (assuming the machine is otherwise top of the line)? If so, I will probably try using a solid-state drive.

Again, my thought is to build a machine that will be able to play any video, from SD all the way to full HD. I do not want a bunch of fans running, though, so I am trying to limit it to what is needed for the power supply, CPU and video card.

If answers on these points are not known yet, that is fine -- I am just starting to formulate what components to buy so I wanted to see what others thought...

[Gamester17]

1. No.
2. No.
3. CPU.
4. No, but XBMC (or rather the FFmpeg video decoders that XBMC uses) does not scale well to multiple CPUs/CPU-cores, so you might only get 20-40% extra from each additional core (which means that a 3,2Ghz Dual-Core can be about as fast as a 2Ghz Quad-Core). (FFmpeg is currently working on developing better scaling, however it might be 6-months before we see any results from that development).
5. Yes but not a lot, the only thing you probably notice would be faster boot time on the SSD.

[BLKMGK]

SPDI/F can handle all of the codecs that XBMC can handle just fine.

this is true however if someone is expecting to be able to use one of the nifty HD sound tracks they might be in for a rude surprise - hence my warning. I have no issues with the current supported soundtracks - it sounds great - but some people want *more* and 7.1 was mentioned - but not which 7.1. TrueHD isn't going to fly for instance (pretty sure) and there may be others.

[Gamester17]

TrueHD isn't going to fly for instance (pretty sure) and there may be others.That is correct, you have to wait until FFmpeg supports demuxing the format, (yes even for SP/DIF pass-through), but they are working on it as we speak. Checkout the ffmpeg-devel mailing-list if you are interested in keeping up with the progress: http://www.ffmpeg.org

More about FFmpeg and why XBMC use it:
http://xbmc.org/wiki/?title=Codec_and_Format_requests

[jkrellner]

1. No.
2. No.
3. CPU.
4. No, but XBMC (or rather the FFmpeg video decoders that XBMC uses) does not scale well to multiple CPUs/CPU-cores, so you might only get 20-40% extra from each additional core (which means that a 3,2Ghz Dual-Core can be about as fast as a 2Ghz Quad-Core). (FFmpeg is currently working on developing better scaling, however it might be 6-months before we see any results from that development).
5. Yes but not a lot, the only thing you probably notice would be faster boot time on the SSD.

Thanks for the helpful answers. It appears my focus should be on CPU and not much else, and that is truly awesome that I will be able to run this from a USB stick (long boot times do not bother me). I never intend to store content on this PC so I do not need storage directly on the machine. I am not even sure it will have an optical drive since I have the PS3 for that.

These answers will enable me to save some serious $$$ come build time. Thanks again.

[blubyu]

jkrellner - Just to give you an example I am currently running an AMD 4200+ with on board Nvidia 6150 and optical out to my Pioneer reciever. I run XBMC on a 4 gig usb stick. I have no hard drives or cd/dvd drives connected. I also just installed a usb wireless card so that I could get rid of my wired network cable. This setup runs just fine for me. I can play any content up to 720p smooth as silk. I can play about half of the 1080p content I have just fine also. To play all the HD content I have I need to bump up my CPU. Other then that I am very happy with what I have.

[jkrellner]

jkrellner - Just to give you an example I am currently running an AMD 4200+ with on board Nvidia 6150 and optical out to my Pioneer reciever. I run XBMC on a 4 gig usb stick. I have no hard drives or cd/dvd drives connected. I also just installed a usb wireless card so that I could get rid of my wired network cable. This setup runs just fine for me. I can play any content up to 720p smooth as silk. I can play about half of the 1080p content I have just fine also. To play all the HD content I have I need to bump up my CPU. Other then that I am very happy with what I have.

Thanks, that's awesome. Based on what I have learned here, instead of building a new machine from the ground up, I am going to try to take my Windows XP machine (which crashed months ago and was replaced by a Vista laptop) and add a sound card (I need S/PDIF) and a better video card if necessary (the current one is a cheap ATI card). I need to perform some testing with HD content. I believe it has an Intel 2.4 Ghz dual core processor.

What are some of the best stress-tests for 1080P HD content? I was thinking that H.264 probably is. If you know of a good sample, please let me know. Otherwise, I might try to pull something from their movie trailers web site.

[jkrellner]

What are some of the best stress-tests for 1080P HD content? I was thinking that H.264 probably is. If you know of a good sample, please let me know. Otherwise, I might try to pull something from their movie trailers web site.

Apple's movie trailers web site, that is...

[althekiller]

Search this forum for "killa sampla"

[Gamester17]

I am going to try to take my Windows XP machine (which crashed months ago and was replaced by a Vista laptop) and add a sound card (I need S/PDIF)Warning here is that there are still no good device drivers for newer Creative sound cards, so get anything but Creative, (read on Ubuntu's website for ask in their forums for recommendations about Linux compatible sound cards will S/PDIF support).

Search this forum for "killa sampla"that, 'the bird scene' from BBC Planet Earth is a bad sample as it is encoded wrong (no bitrate limitation) and is the very extreme. On the other hand if you have a computer capable of playing it then it will be able to handle it. I mean a 2,4Ghz Intel Core 2 Duo should be capable of handling 99% of all 1080p H264 videos out there, but it will still fur sure drop frames and stutter when playing 'the bird scene' from BBC Planet Earth in XBMC today.

[althekiller]

I'm not sure what your definition of "stress test" is. But mine is, "put the system in a situation far greater than it should see in normal use," which the killa sampla does nicely.

[jkrellner]

I'm not sure what your definition of "stress test" is. But mine is, "put the system in a situation far greater than it should see in normal use," which the killa sampla does nicely.

Yes, that's what I am looking for, so I'll take a look. But it is reassuring that my current processor should be able to handle 99% of what is out there.

[jkrellner]

Warning here is that there are still no good device drivers for newer Creative sound cards, so get anything but Creative, (read on Ubuntu's website for ask in their forums for recommendations about Linux compatible sound cards will S/PDIF support).

Thanks for the heads up on Creative. I hate their devices anyway (usually overpriced). I am planning on getting the HT Omega Striker:

http://www.newegg.com/Product/Product.aspx?Item=N82E16829271001&Tpk=ht%2bomega%2bstriker

[BLKMGK]

Clock that 2.4 up to about 3Ghz and it will likely play the Bird Scene if the video card is up to snuff. I'm likely running the same CPU you are only overclocked a bit and the Bird Scene plays without any dropped frames or did last I tested. A cheap cheap Linux supported audio card with S/PDIF will do you fine. GL and please let us know how it goes!

[jkrellner]

Clock that 2.4 up to about 3Ghz and it will likely play the Bird Scene if the video card is up to snuff. I'm likely running the same CPU you are only overclocked a bit and the Bird Scene plays without any dropped frames or did last I tested. A cheap cheap Linux supported audio card with S/PDIF will do you fine. GL and please let us know how it goes!

Thanks dude. I will definitely try that once I figure out how to overclock (I have never done it before). I do have a massive fan for my CPU so it should be safe. If you know of any good overclocking guides, let me know. I think Tom's Hardware might have some good tutorials. I'll report back here once I manage it and hopefully will be able to tell you all the bird scene runs great without any dropped frames!

[BLKMGK]

In this case you simply need to bump the FSB setting in the BIOS up a bit. I don't recall what mine is set to but other changes weren't necessary. Start at stock speed first, may prove to be just fine for your content!

[althekiller]

I like how this thread went from "specifically sound" to "overclocking." It was a good attempt guys, almost a thread could be useful in the future.

[jkrellner]

I just realized my PC has a 2.8 Ghz CPU, which is GOOD.
I also just realized my PC has an IBM Motherboard, which is BAD... no overclocking in the BIOS.