Please consult the list archive for more on my setup. Quick recap: * Frontend/backend: 3.0GHz Hyperthreaded Pentium 4 with 512MB running Fedora Core 4 and MythTV 0.18.1 from ATrpms * Program sources: Two Motorola DCT-6200 boxes through FireWire (Point-to-point at 200Mbps). * MythTV storage: Infrant ReadyNAS 600 gigabit Ethernet-capable NAS in ext3 over RAID 0, mounted via CIFS [1] * Network: D-Link PCI Express gigabit Ethernet card and SMC gigabit Ethernet switch
My experiences: * Frontend/backend (frontend presumably swapped out to disk, DPMS on) and storage are idle: Two HDTV (from the premium movie channels, say) programs record simultaneously without IOBOUND errors. One high-bandwidth [2] HDTV program, or one high-bandwidth and one regular HDTV, seems OK; I haven't empirically tested two yet, but believe it should also be all right. * I'm watching a HDTV program and I'm also copying non-MythTV files from the Infrant to another machine on the network: One HDTV program and one non-HDTV program record simultaneously without IOBOUND errors, generally speaking, except a burst for 4-6 seconds at occasional five-minute multiples as Brandon Beattie and I have discussed here recently. Two HDTV recordings at once result in steady IOBOUND errors. * I delete a program from the frontend: A few lines of IOBOUND errors regardless of what I am recording. Interestingly, deleting files outside mythfrontend doesn't seem to be a problem, as I think I've recently noted. * Frontend/backend is idle, and I'm also copying non-MythTV files from the Infrant to another machine on the network: Two HDTV programs record simultaneously without IOBOUND errors. One high-bandwidth HDTV program (such as anything from HDNet) generates slightly more serious (up to about 10 seconds) IOBOUND bursts at occasional five-minute intervals. * A single medium-load commflag job is running and I'm also copying non-MythTV files from the Infrant to another machine on the network: One HDTV program records with 4 to 6-second IOBOUND bursts at occasional five-minute multiples. Bandwidth use: * Digital non-HDTV channels generate the smallest files at about 900-1000MB/hour for a movie channel and up to 1200MB/hour for a cartoon (with probably a lower-quality feed). * Analog channels such as TCM generate about 2900MB/hour due to the extra noise. HDTV movie channels generate about 4400MB-4700MB/hour. * A high-bandwidth HDTV channel generates 7400-7700MB/hour . . . * Except for ABC (and, presumably, Fox), whose 720p programs record at about 5.8GB/hour. Other notes: * I've seen the occasional mangled channel change (typically a digit dropped) over FireWire when using live TV, but haven't seen it yet with a recording. * I still *do* see the dreaded "recording previews fine but kills mythfrontend on playback or at first OSD display [or at best, OSD doesn't come up at all]" issue with perhaps one of every dozen recordings. I haven't noticed any particular pattern regarding channels, but this is my #1 annoyance with MythTV at the moment, and--if I may plea to the developers and/or the ATrpms packager--ample justification for an interim hotfix release for the 0.18.x series as opposed to having non-SVN users wait for the fix I understand is in SVN to appear with 0.19. (By contrast, I can live with "frontend crashes after two or three source changes during live TV" and "changing channels in live TV mangles the sound, requiring an escape and reentry into live TV to fix" issues; as an old TiVo hand I know just how useless live TV generally is.) [1] Please see the list archives for why I use CIFS and not NFS. [2] Such as anything from HDNet or Discovery HD Theater and, interestingly, most network affiliates over cable. I presume OTA broadcasts' bandwidth demands would be even greater. -- Yeechang Lee <[EMAIL PROTECTED]> | +1 650 776 7763 | San Francisco CA US _______________________________________________ mythtv-users mailing list [email protected] http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
