Spec me a MythTV Frontend

BillytheImpaler

BillytheImpaler

BillytheImpaler

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I'm mulling over the idea of building a MythTV system. MythTV is a system of PVR software for Linux. It uses a client-server model so I am going to have the DVB and analog cards in a powerful computer stashed away. It'll feed recorded TV shows over the network to a frontend client. The idea behind this is to minimize the size and power necessary for the machine. I'd like to get away with one 60 mm fan for it all but I'm flexible.

I wanted to use an old laptop I have, Pentium M 1.5 GHz with 855GM graphics/chipset, for the frontend but I'm having all sorts of issues, mainly that the thing is horribly broken with no working HDD or ODD. Wait a minute, that's probably why I stopped using it in the first place! Since it won't boot from USB or firewire I'm looking at alternatives.

I'd like to see what a cheapish SFF PC might be able to do. All it needs to have is VGA and S-Video out and a 100 Mbit Ethernet port, and a 2.5" IDE port or Compact Flash slot. I'll be running the whole thing from a 1 GiB Compact Flash card.

I'd very much like to avoid any VIA bits, either CPU or chipset. It would be an extra bonus if I could reuse the skt479 Pentium M or the SODIMM DDR memory. What can you show me? I'm quite the n00b when it comes to small lower-powered devices.

EDIT: I'll be custom making a case for it so form factor doesn't matter. I'd like to keep the overall height under 100 mm if possible so I won't be using any expansion cards. Do SFF boards ever come with discrete graphics like some laptops do? nVidia graphics onboard would rock my socks.
 
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bumpsa7.jpg

Bump for great justice? All I really need is a small motherboard with nVidia graphics onboard. I can come up with the rest of the system pretty easily. I'm just not aware of what's on the SFF market.
 
Whoa, that's about as much as I intend on spending on the whole project including both computers. :p

Moving beyond skt479 are there any deals to be had with other architectures, either AMD or Intel? AM2 CPUs are darn cheap now.

Perhaps an ATX board with a half-height GPU would be a better choice. I'm still early in this project to I'm pretty free to experiment with ideas.
 
Dual cores would be a waste since it'll only ever be decoding one stream at a time. A gig of RAM too would be a waste since it could get by on 128 MiB. How's this look:
cartoy0.png


Has anybody used that cooler? Is there any way I can have an external PSU with a standard ATX board? Perhaps a small transformer that installs inside and is fed CD at, say 17 V, from an external laptop PSU. I already have a crap generic 350W PSU that should be able to cope with such a machine should I have to install one internally. I'd just like to be able to use a laptop-style fanless external PSU.

EDIT: Yes there are:
mediane0.jpg

:D
 
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Sounds good, Hades. If I was going for a combined front and back end I'd definitely do as you are doing. Which AM2 processor currently available has the lowest thermal dissipation? THG traditionally posts "Mother of all CPU Charts" but they seem to be lacking one for 2007, the latest one being for 2005-2006.
I'm going to be using a Hauppauge PVR-250 analog MPEG2 hardware encoder to begin with some sort of DVB-S card to be added at a later date. What card do you have in mind, a PVR-350 with remote?
 

That appears to be AMD's lineup of 35W CPUs. That X2 3800 is quite tempting, especially since I can't find any of the others for sale for less money than the X2 would cost. It'd be mega-overkill but at least I could keep it busy running Folding@Home or something. ;)

I could even double my order and get another identical system to be the backend. Now THAT would be overkill. :D
 
Crap. In a fit of lunacy I odered an ADA3800CUBOX, the 35W version of the X2 3800+, an M2NPV-VM, and the AC heatsink I asked about above. That should be more than sufficient for most anything. Hopefully the chipset will get along nicely with nVidia's Linux drivers. I will most definitely report back. :D
 
Pulse said:
and you totally dis-regarded it when i said about having the x2 :(
Click to expand...
I did but looking at the numbers it seemed like it was a good use of $35 once I considered it more fully. Moving from the 60W Sempron to the 35W Athlon means that I might not need any more case fans. I'll see what I can accomplish with ducting. It's still ridiculously overpowered. I'll have to run a 64-bit OS and Fold on it to make good use of the power.

I'd have liked to have gotten one of the 35W Semprons but I couldn't find anywhere that had them in stock.

EDIT: I've been brainstorming on ideas for the case for the frontend. The current favorite is this:
casekp8.png


It would have nothing on the front at all. The structure would be brushed stainless steel and stained wood, milled to accomodate the edge of the metal. If a case fan is necessary it'll be a 120mm Yate Loon blowing up from the bottom exiting the rear. If I decide to install a DVD player it would be accessible from the left hand side. When construction begins expect a noobish thread in Case Central to document it.

EDIT2: We'll see if anybody notices this secret edit. I've been working on the mobo tray design. This is how it's looking.


That includes a 120mm main intake and the PSU's 80mm intake. I'm concerned about the size issue. It needs to be over 18 inches wide so it matches with the other AV equipment but I don't want to make it too large. It's simply a work in progress.

EDIT3: Ooh, I'm so stealthy. No one will ever read this!

That's the final case design. When I'm happy with everything I'll post up the .sldasm, .sldprt, and .dwg files for your perusal.

EDIT4:

The design is coming along swimmingly. The mobo tray has changed a little since my last edit. All that's left is the back end and measuring all the real parts when they arrive for the purpose of double-checking.
 
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