How Many Simultaneous Recordings in HD?

[tjb]

I have been having problems with some recordings lately. The symptom looks like a weak signal (skipping and stuttering, etc), but normally it is only at the beginning and end of recordings. A few days ago, I had 3 programs scheduled to record at the same time. One of the programs was basically unwatchable throughout.

I'm wondering if I am running into limitations on the speed of my hard disk. Has anyone else been able to record 3 HD recordings simultaneously? I have 2 250 GB SATA (1.5) drives that are runnning in Raid 0 for a total size of 500GB. If it is hard drive performance, is there anything alse I can try? The sector size was set at 64MB when it was formatted.

[-stattik-]

Unless your hard disks are severely fragmented, you shouldn't have any problems. I've got a 3 disk RAID 3 setup and regularly record 3 HD shows and 1 SD show at once. The shows only write 2 MB/sec to the disks each which shouldn't cause a problem.

[flyswatta]

My guess would be signal strength on the channel that had the crappy recording. Is this OTA or QAM? If it's OTA are you boosting the signal at all? I just replaced a 3 way splitter with a 4-way 10 db amplifier and it solved my problem (cost $9.95 at a local electronics shop). Err, this will only help you if you are losing signal strength because of a long cable or multiple splits - it won't make a poorly received station tune in any better.
You could try going into gbpvr.exe, bring up the channel in Live TV and press Control-O, that will show your signal strength and quality. I was going nuts trying to get that to work in PVRX2, and found a post by Sub that said that he hadn't implemented that in PVRX2 yet.

[Jaggy]

I have been having problems with some recordings lately. The symptom looks like a weak signal (skipping and stuttering, etc), but normally it is only at the beginning and end of recordings. A few days ago, I had 3 programs scheduled to record at the same time. One of the programs was basically unwatchable throughout.

My 'brother in law' was having the same problem with his myth system with recording DVB-S programs (was fine for normal analog) & was pointed to

http://www.mythtv.org/wiki/index.php/PCI_Latency

& his exact words were "Fortunately that VIA motherboard allows me to set the latency via the BIOS, and blow me down it works really well." I haven't had a chance to play with it yet on my system but may be worth having a look at.

[tjb]

My guess would be signal strength on the channel that had the crappy recording. Is this OTA or QAM? If it's OTA are you boosting the signal at all? I just replaced a 3 way splitter with a 4-way 10 db amplifier and it solved my problem (cost $9.95 at a local electronics shop). Err, this will only help you if you are losing signal strength because of a long cable or multiple splits - it won't make a poorly received station tune in any better.
You could try going into gbpvr.exe, bring up the channel in Live TV and press Control-O, that will show your signal strength and quality. I was going nuts trying to get that to work in PVRX2, and found a post by Sub that said that he hadn't implemented that in PVRX2 yet.

I know it sounds like signal strength, but the channel that failed (OTA by the way) is ALWAYS ay 100%. That's why I tend to think it is a disk performance problem.

[tjb]

My 'brother in law' was having the same problem with his myth system with recording DVB-S programs (was fine for normal analog) & was pointed to

http://www.mythtv.org/wiki/index.php/PCI_Latency

& his exact words were "Fortunately that VIA motherboard allows me to set the latency via the BIOS, and blow me down it works really well." I haven't had a chance to play with it yet on my system but may be worth having a look at.

Thanks, I'll give that a try.

[flyswatta]

I know it sounds like signal strength, but the channel that failed (OTA by the way) is ALWAYS ay 100%. That's why I tend to think it is a disk performance problem.

Fair enough, please let us know if the PCI Latency thing worked out. I found it an interesting read and am curious to hear of your experiences with it.