[exchequer]

I noticed some lag on my xbmc playback, especially when SABNZBD was downloading.

I dediceded to check it out with a heavy file and I noticed the following (1080p 2.7gb 1 hour file).

i5 2500k with gtx460 for comparison:
VLC: 4% cpu and 15-20% gpu

AMD E-350 (integrated Radeon HD 6310 ) with Windows XP Pro SP3
Player Classic Home Cinema: 23% cpu usage
VLC: 52% cpu usage
XBMC: 77% cpu usage (1 core maxed out)


So my best guess is that XBMC is not using the 80 shader cores included in my cpu. Anyway I can confirm this? Unfortunately GPU-z does not show gpu usage .

edit I updated to catalyst 11.12 and it helped a bit:

Player Classic Home Cinema: 13% cpu usage
VLC: 40% cpu usage
XBMC: 78% cpu usage (2 cores at 77-78 load this time!)

[0wing]

XBMC has DXVA2 acceleration, you need Vista/W7 for that.

The lower CPU for VLC is probably because of multi threaded decoding, XBMC doesn't have that.

[exchequer]

I chose Windows XP because it only uses 5 GB hdd space and 400mb ram. My machine was intended as NAS. Untill I discovered XBMC ^^.

I could try windows 7 but im not sure if I would benefit from it given its tons of background processes. I do have 4 gb ram so technically I guess it is possible.

[ashlar]

XBMC has DXVA2 acceleration, you need Vista/W7 for that.

The lower CPU for VLC is probably because of multi threaded decoding, XBMC doesn't have that.

I'm pretty sure XBMC does indeed have multi-threaded decoding. Otherwise it wouldn't be able to cope with Bluray bitrates in software mode, when instead it does on a 3GHz CPU (back in the days before it started supporting DXVA2).

[0wing]

I'm pretty sure XBMC does indeed have multi-threaded decoding.

Well, you're wrong. XBMC does not have a multi threaded version of ffmpeg.

[GameAction]

I chose Windows XP because it only uses 5 GB hdd space and 400mb ram. My machine was intended as NAS. Untill I discovered XBMC ^^.

I could try windows 7 but im not sure if I would benefit from it given its tons of background processes. I do have 4 gb ram so technically I guess it is possible.

problemi is that you're using xp. no dxva2 under xp so your cpu is used instead.
windows 7 or vista is needed, remember to remove all unecessary service and it will go better than xp

[ashlar]

Well, you're wrong. XBMC does not have a multi threaded version of ffmpeg.

Shouldn't this lead, in a dual core setup, to a single core only being used for decoding, ie. max 50% CPU usage? I seem to remember at least two cores are used...

[j114]

You can use rt7lite (found here) to remove components you may not need for a simple htpc build thus reducing size on disk after install. Then you can use Black Vipers awesome guides to identify and disable any services that you don't need. If you're not using the machine as a primary machine for browsing the web and normal daily tasks, there is a lot of stuff you can safely disable to reduce the memory and processor footprint. Just turning off aero (use the "Windows Classic" desktop) will immediately reduce overhead.

I also have an E-350 setup and I can tell you from experience that you will get a lot more out of that rig using windows 7 than you will from XP. XP is still a great operating system, but unfortunately it is rapidly becoming obsolete for many things such as video/graphic processing with more modern hardware. If you are willing to sacrifice hardware acceleration for a smaller footprint anyway, then you would be better off using one of the many *nix solutions out there. You can have a much more powerful and flexible NAS setup using one of those systems.

[bobo1on1]

Shouldn't this lead, in a dual core setup, to a single core only being used for decoding, ie. max 50% CPU usage? I seem to remember at least two cores are used...

Decoding is not the only thing that uses the cpu, that being said we had a multithreaded h264 decoder at one point, but that was an unofficial ffmpeg patch, which we removed because it was incompatible with an ffmpeg update.
XBMC currently does not have a multithreaded decoder.

[ashlar]

Decoding is not the only thing that uses the cpu, that being said we had a multithreaded h264 decoder at one point, but that was an unofficial ffmpeg patch, which we removed because it was incompatible with an ffmpeg update.
XBMC currently does not have a multithreaded decoder.

Ok, so it used to have it and now it doesn't. That explains what I remembered. Are there plans to bring it back?

[>>X<<]

Multithreaded was in Camelot it disappeared with Dharma

[exchequer]

You can use rt7lite (found here) to remove components you may not need for a simple htpc build thus reducing size on disk after install. Then you can use Black Vipers awesome guides to identify and disable any services that you don't need. If you're not using the machine as a primary machine for browsing the web and normal daily tasks, there is a lot of stuff you can safely disable to reduce the memory and processor footprint. Just turning off aero (use the "Windows Classic" desktop) will immediately reduce overhead.

I also have an E-350 setup and I can tell you from experience that you will get a lot more out of that rig using windows 7 than you will from XP. XP is still a great operating system, but unfortunately it is rapidly becoming obsolete for many things such as video/graphic processing with more modern hardware. If you are willing to sacrifice hardware acceleration for a smaller footprint anyway, then you would be better off using one of the many *nix solutions out there. You can have a much more powerful and flexible NAS setup using one of those systems.

At this point I have 100gb assigned to my C drive. However I was planning to switch to a 30 gb ssd for os+XBMC+sabnzb+sickbeard+couchpotato+etc. With XP this would fit fine but officially win7 uses 20 GB.

How much can be stripped ? (My winsxs folder on my main rig is almost 7gb).

Also I would like to add that regarding the cpu usage; after I updated to the latest catalyst xbmc uses 2 cores at 78% load with a better framerate compared to the earlier results where I expierenced a full core+50%=77% avarage. Still XBMC uses double the cpu of vlc ^^.

[Jogee]

Why don't you try using Linux version of XBMC, or try out the Live version if you want to see how well it will work before committing?

Ciao.

[Mallet21]

You could also setup XBMC to launch an external video player (MPC-HC) that would allow for hardware acceleration.

[j114]

This is one of my vanilla Win 7 Ultimate installs on a VM:



The only thing installed on that system other than the operating system is Python 2.7. As you can see, it doesn't take up that much disk space without any tweaking.

I have a Win7 Ultimate install on a 32 gig SSD (using an E-350 mobo) with XBMC, sickbeard, couchpotato, sabnzbd, Git, MySQL 5.5, SP1, a couple of hand picked windows updates after SP1, python 2.7 (I run SAB, sickbeard and couchpotato from source), and a couple of very small miscellaneous utilities. I removed stupid things like games, unnecessary drivers (THINK this one through, consider potential future needs), Windows search, Media Center, Gadget platform, extra languages (particularly Asian languages--they tend to be huge) and probably a few other small things that I am not thinking of off the top of my head. I also do not enable hibernation or system restore on any machine, ever. Here is that machine:



In theory, that is plenty. In practice, I will need to keep a close eye on my database size and thumbnail cache. The thumbnail cache in particular has been reported to grow to 10+ gigs for users with very large collections or high turn over collections. My thumbnail cache has been maintaining ~2 gigs so I believe I will be ok for quite a while. I also disabled the recycle bin so I can be sure that I don't waste disk space by forgetting to dump it on occasion.

Finally, here is a XP VM that is fully updated and only has 2 small programs installed:



Smaller, yes. But considering the relatively small difference (5 gigs is chump change today, come on) vs. performance and features, I'll take 7 (for this application).

20 gigs for a full install that is strictly windows is very high and I find it hard to believe anyone has an install that size. Maybe if you installed ALL updates.

In regard to your winsxs directory concern, I would recommend a few articles to further educate yourself about that particular directory.

Explanation of the WinSxS directory

In a nutshell, the size of this directory depends on how much software you install and uninstall (and what the uninstaller leaves behind!). For the scope of our application, as discussed in this thread, this should not become an issue for you.

Some really good conversation about the WinSxS directory size being misreported.

And finally, some instructions for safely cleaning the WinSxS directory.

If you're still concerned about size, then one of the linux, live, or openelec versions are probably a more viable option for you as they will be quite a bit smaller and still likely to have better performance than XP.