Minimum Spec for HD in Linux/XBMC

[dvd.collector]

Hi All. I already a long established XBMC user on the xbox, and like a lot of other people am looking for a HD playback solution.

I'd love to keep XBMC as I love the interface, which brought me here to the Linux version.

I have some 'old' kit lying around which I'd like to setup as a HTPC if its powerful enough to run everything I can throw at it.

I have:

Asus P4 mobo (AGP graphics)
P4 2.8ghZ (had this oc's to 3.2 previously)
2GB DDR ram
old cheap geforce AGP graphics card.

I'm really wondering if I bought a decent AGP card, would this take enough load off the CPU to make this old kit viable? What I dont want to do is buy an expensive AGP card which then leaves me stuck if I want to upgrade in the future to a PCI-E mobo.

[snappz]

I am using a P4 3Ghz (Hyperthreading)
Asus P5GD1-VM (with homebrew S/PDIF)
1.256GB Ram
PCIe Geforce 6600 gt

It plays most mpeg 2 stuff (1080i, 720p TS etc) with no problem. Starts to struggle a little with x264 stuff. Still tweaking and playing with it though so I expect more improvement yet. I would think a video card similar to this in AGP wouldn't be too expensive. I think I have had this one for a few years now.

[FlappySocks]

As far as I know, the problem at the moment are Linux drivers. Non of them offload decoding to the graphics cards beyond mpeg2.

I'm itching to build three bare-bones XBMC-linux boxes capable of doing 1080p, but I dont know if I should get one based with an onboard Nvida,ATI, Intel or S3.

[fysa]

I'm currently using:

A8N VM-CSM MicroATX 939 w/On-board GeForce 6150
Athlon 64 3200+
1GB RAM

A very cheap setup -- will play 720p x264s with no issue in xine or mplayer. Definitely not fast enough for 1080p x264. I've had no problem with 720/1080 TS in mplayer or xine because of XvMC off-loading, but haven't tested that in XBMC yet.

The biggest issue right now seems to be that 720p x264s can *almost* play fine in XBMC with vsync off. As soon as vsync is on, performance goes to crap.

SPDIF/digital output works great with a custom SPDIF line in XBMC config. (simply "iec958" was not enough -- I copied the complete line from my ~/.xine/config and it now works perfectly, as long as I have UI sounds off)

I'm not entirely convinced that 1080p x264 will ever be possible with the 939 chipset.

[gateway69]

Hey, I also wanted to write up my exp, now that I have my box working like It should:

smb mounts, remote, open gl (nvidia), digital sound out some of my tests using apples HD files are a bit dissapointing at the moment.

my system is a shuttle box with dual core amd 64 x2 3800+ chip , 2 gigs of ram and some 8800 nvidia card with hdmi and dvi out.

Testing clips from this page http://www.apple.com/quicktime/guide/hd/

I found that cpu was pegged at 100% most of the time and alot of dropped frames.

someone mentioned the nvidia card drivers arnt being used yet to offload video rendering?

Im also seeing alot of screen tearing when playing back files.

Im running at 1920x1080 on my 65 inch 1080p tv via hdmi.

[fysa]

The 8800 is definitely overkill there. It will likely be quite sometime before we see H264 acceleration out of an nvidia device. 3GHz+ is required for 1080p x264 currently (i.e., that Apple HD video) -- which means Athlon 64 5000+ or better if you're running AMD.

[dvd.collector]

Thanks for all the replies.

So I think what I'm hearing is that for XBMC Linux a more powerful CPU is more important than a better GPU, because not much offloading is done to the GPU currently?

Which means I will need to save up for some decent kit then

[gateway69]

yea seem like cpu is the big one right now until we get some sort of playback using the nvidia drivers for speed up which who knows when... be curious to see what min hw specs for software playback are for

1080p
720p

x264
h264

[d4rk]

8800 isn't overkill and just because video decoding isn't offloaded to the GPU doesn't mean that the GPU is sitting idle. Video filtering, deinterlacing, etc are all done on GPU, and XBMC will eventually become much more GPU intensive than it is currently as higher quality video filters and deinterlacing methods are implemented. We haven't decided on a target hardware spec but if you need to pick up a grx card today, get the best one you can afford (nvidia preferably). Ideally a PCIe so that readback speed is fast.

[ashlar]

Originally Posted by d4rk

8800 isn't overkill and just because video decoding isn't offloaded to the GPU doesn't mean that the GPU is sitting idle. Video filtering, deinterlacing, etc are all done on GPU, and XBMC will eventually become much more GPU intensive than it is currently as higher quality video filters and deinterlacing methods are implemented. We haven't decided on a target hardware spec but if you need to pick up a grx card today, get the best one you can afford (nvidia preferably). Ideally a PCIe so that readback speed is fast.

Care to elaborate on how you plan to offload work to the GPU? Are there portions of video processing that are possible with current nVidia drivers?
I have a 7300GT passively cooled and that, coupled with an E2160 OCed to 2.4GHz, has been enough to play all content that I've thrown at it so far under XP and using CoreAVC to decode h264 material.