[mythtv-users] Which USB DVB-T Device should I choose, in a 266Mhz Linux Box

Steve Smith st3v3.sm1th at gmail.com
Mon Feb 18 14:03:30 UTC 2008

On 18/02/2008, Sarah Hayes <sarah at sarahhayes.is-a-geek.net> wrote:
> Guan Xuefei wrote:
> > Hello folks, I am new to MythTV, I have a old linux box (266MHz CPU),
> > I would like to choose a USB DVB-T box, and It should have the
> > hardware encoder because the poor CPU, I checked the mythtv website,
> > and it takes me to here,
> > http://www.linuxtv.org/wiki/index.php/DVB-T_USB_Devices, a lot of
> > devices for me to choose, If anyone have ever use those devices,
> > please give me some advices. Thanks.
> >
> > Guan,
> Whilst, yes, DVB cards require very little to no CPU overhead, I'd be
> dubious of using a USB one on such a beastie.
> A lot of them I've encountered seem to be USB2 not USB1 or 1.1 (and
> yes, I've encountered old boards that were pre-usb spec with what
> amounts to the USB equivalent of early pre-N on them... i.e. nowt worked
> properly with anyone else's stuff), backwards compatibility is one thing
> but volume of data another.  I'm also dubious because USB devices do
> seem to take a hit on the CPU and well, you'll have the data stream
> being written to the disk; can it cope?
> A good question to ask is "How much throughput does a disk need to write
> an mpeg2/whatever it appears as stream?" and compare the average against
> a hdparm -tT /dev/hda if the result is higher you're ok, if not, you'll
> possibly be dropping frames on recording.
> Is this little machine going to be an "all-in-one"?  If so keep in mind
> that MySQL will be running on it and both the frontend and backend
> programs, so you might want to max the memory on the system; which is
> probably PC100/133 SDRAM and thus dirt cheap.  Being an older board it
> probably won't take all that much so not an expensive proposition :)
> Would it work?  Probably.  Would it be a good long term solution?
> Probably not, but handy for figuring out if MythTV is for you and then
> throwing bigger (but not necessarily cutting edge) hardware at it, say a
> PIII or early P4 for both recording and perfect playback :)
> Sarah
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A 266Mhz machine could make an OK Mythbox backend with the addition of a
MediaMVP to do the playback.
(I used to run GBPVR on an early 800mhz mini-itx which was incapable of
playing mpeg2 so I used that as the recorder and MediaMVP as my playback

Though as others have suggested I'd go for a PCI based DVB-T device as the
USB solution may place too much load on the CPU (+ you'd probably need a
USB2 card anyway).

So nip on over to ebay and pick yourself a second hand MVP....
or if you want an all in one box solution, ditch the PII machine and buy a
second hand P3/P4/Athlon etc
(P3 700mhz+ is sufficient for SD, some have used less!)


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