[mythtv-users] Hardware questions

[Chad Vogelsong]

I just bought the parts to put together a new MythTV box.  Here is what I did.


> -----Original Message-----
> From: Reid Peryam [mailto:reid at bu.edu] 
> Sent: Monday, August 25, 2003 9:45 PM
> To: mythtv-users at mythtv.org
> Subject: [mythtv-users] Hardware questions
> 
> 
> I'm building this computer in order to act solely as a TiVo (for the 
> immediate future). Here goes.
> 
> 1. Where the hell can I buy this PCI "video encoder" that is talked 
> about on MythTV.org's website? Haven't found one yet.

The video encoding is done either in software or hardware.  I bought 2x Hauppauge PVR-250 cards.  They are more expensive, but they offload the CPU by performing the video encoding in hardware.  I found them for around $133 / card on directron.com .  For your entire setup, you need as many TV Tuners as you want for simultaneous recording / watching.  For instance, with my 2 cards, I can record a show & watch live TV at the same time.  Or I can record 2 shows on 2 separate channels at the same time, but can't watch TV while doing it.

 
> 2. How good of a sound card should I buy? I was thinking of going 
> cheap, but then I was thinking that if the entire signal is 
> going to be 
> coming from the computer to the television, I should probably have 
> something that can sound pretty good (6-channel for option of 
> speakers).

I bought a SoundBlaster LIVE! 5.1.  It seemed to be the best bet between high quality & low cost.  $36.00

> 3. Is a video card important at all? The encoder will probably be 
> pushing all of the bits, I'm thinking. I was thinking of 
> going with two 
> separate cards, a video card and separate PCI TV tuner. If Graphics 
> aren't at all important then I'm thinking that an AGP 4x/8x 
> motherboard 
> isn't needed?

You need some kind of video output to the TV.  The motherboard I got for mine has on-board video out, but I bought a nVIDIA GeForce4 MX440, 8x AGP, 64 MB with TV Out.  The graphics card does the "decoding" of the video stream.  The A/D converter on the Tuner (hardware) or the CPU (software) does the encoding of the various input streams.

> 4. Is the TV tuner important at all? It seems as though all 
> you need it 
> for is the coaxial line-in port. Any other things I should look for 
> when buying it or is bare bones good enough?

TV tuner is important.  You need to get one that is supported by Linux, whether by the bttv, gatos or proprietary linux driver.  If you have a slow CPU you want to use, you will need one that does hardware encoding like the PVR-250 by Hauppauge.  Look in the mythtv FAQ for the hardware questions.
 
> 5. Hard Drive. The website says about 2 gigabytes/hour while 
> recording. 
> For some reason this seems really low to me. Is that for a smaller 
> resolution? So the drives are all pretty cheap, but what I'm thinking 
> of is that if I had a 10,000 RPM drive ($B!b(J 7,200) fast forwarding and 
> track marks would respond *much* faster. There is a huge price 
> difference though and the max capacity for a 10,000 RPM drive is only 
> 36 megabytes. Maybe one 10,000 rpm drive for main usage and a 
> residual 
> 7,200 drive for spill over? I doubt I'd be recording more 
> than 10 hours 
> at a time (length of two football games), even over vacations. Any 
> thoughts?

The 2 GB / hour is dependent on recording resolution & quality.  It can vary from 600 MB / hr. to 4 GB / hour.  Most people are very happy with their 5400 RPM drives and those that aren't, a 7200 RPM drive is more than enough.  Unless you have mucho dinero to blow on this, I wouldn't waste your money on super speedy drives.  Go for capacity before rotational speed.  I'm using a NFS mount of a mixture of 5400 & 7200 RPM drives (in LVM config) totaling about 0.5 TB of tv / mp3 / dvd / video / game storage.

> 6. Linux. I've never done a thing in Linux but have experience in 
> UNIX... anyway I'm hoping to learn. Also -- Red Hat, Madrake, Debian 
> etc. -- which is right? MythTV seems to suggest that Red Hat has a 
> bunch of settings that are naturally in conflict with it that need to 
> be modded, yet Red Hat seems to be the most popular version. I was 
> gunning to install the barest of Linux OSs on this computer 
> as I'm not 
> using it for anything except TiVoing, MP3s, and maybe a few games.

I'm using Mandrake 9.1 for my system.  Very small amount of problems.

> 7. Is more than 256 RAM worth it?

Unless you are using the box for some other applications, 256 MB is just fine.

> 8. Will I be able to record two separate channels at the same 
> time? If 
> so do you think I should dual process it? What other 
> components will be 
> affected?
 
MythTV can record over 4 simultaneous sources at once.  It uses a distributed architecture.  You can use the tuner cards from serveral computers in conjunction to get simultaneous streams.  I have 2 tuner cards in my backend server to do the encoding and 0 tuner cards in the box by the TV.

> This is so much more expensive than buying a TiVo but it's 
> going to be 
> a lot more fun!
> 
> Thanks!
> 

You're right about that.  I laid down about $650 for all the hardware, plus some stuff that I had around the house to put mine together.  But it's well worth the effort.

Chad