Interesting hardware comparison -- not sure what it means..

[osx-addict]

So.. I had setup initially an older Macintosh G5 desktop (1.8Ghz) server to use as my initial SageTV server that was configured to :

1) Talk to two HdHomeRun network units connected via a Gigabit switch in my garage
2) Stream content from the server to a HD300 located about a 100 ft away via two network hops over a pair of gigabit switches -- the one in the garage mentioned in #1 and another in the master bedroom closet.

The Mac did a fine job running SageTV6 without problems -- no dropouts to speak of while it was running and tuning in OTA signals for 3-4 days.

Over the weekend I bought a used HP DC7700 PC running an Intel Core 2 Duo processor at 1.86Ghz with 320Gb SATA drive -- using Windows 7 Professional for just over $100. I was able to install SageTV 7 and the drivers for the HdHomeRun tuners without problems. However, in watching 1 TV show streaming over almost the same exact network drop (the PC is connected to a different port on the garage switch), I'm seeing regular artifacts/dropouts..

Is it possible that my lowly 1.86Ghz Core 2 duo is too slow and the G5 is a better match for this type of 'work'? I'm having a hard time believing that..

The good news is that the PC can move up to a Core 2 Duo 2.66Ghz processor to get a speed bump.. I'm thinking I might need that.. Am I missing something? Perhaps to be fair I could load SageTV 6 on the PC for a more equal comparison?

P.S. I'm only doing any sort of viewing on the HD300's -- nothing local on the PC (or MAC for that matter)

[blade]

Originally Posted by osx-addict

Is it possible that my lowly 1.86Ghz Core 2 duo is too slow and the G5 is a better match for this type of 'work'?

No, writing digital streams and streaming to clients requires very little processing power.

[osx-addict]

Originally Posted by blade

No, writing digital streams and streaming to clients requires very little processing power.

That was my assumption as well.. When I start seeing the effects again, I'll peek in on the PC and see if something odd is happening in parallel (e.g. virus definitions updating or doing full-disk scans,etc).. I'm fairly new to windows7 and perhaps some sort of service is running in the background when this is occurring..

My big concern is whether this machine will be overloaded if I'm trying to record up to 4 streams from a pair of HdHomeRuns while streaming to two different HD300's.. I'm hoping it's a no brainer.. For now I've got no plug-ins, no comskipping, etc.. Obviously adding some of that may impact things..

[Fuzzy]

Is it still using all the original hardware in the used pc? it might be a harddrive issue.

[osx-addict]

Originally Posted by Fuzzy

Is it still using all the original hardware in the used pc? it might be a harddrive issue.

Not exactly.. The drive that came with the machine is a 320Gb drive which was never offered on the original machine from HP -- the largest was 250Gb.. I was going to move to a larger drive anyway since 320Gb is way too small.. This machine does support something called SATA emulation making the SATA interface look like either IDE or something else (AHCI? -- I don't recall).. I'm not sure if this is enabled (in BIOS) or what its set to if enabled. I'm guessing that 320Gb drive may be 3 to 4 years old -- wild guess.

I was using the machine last night for several hours and noticed constant issues on our local channel 2 and some issues on other channels but not as bad -- I pulled up the Video sources menu and checked the signal strength for that channel (2) and it was almost constantly 92% strong.. I also bumped the Processor Affinity on Windows allowing the SageTV process to be run on a single CPU (CPU #1) and bumped the priority to high -- all with zero effect on the issue. When Sage is streaming is it write it to disk and then streaming from the disk to the HD300's (or other extenders)? If so, then I'd tend to agree with you on the disk issue.

In checking the Task Manager, I saw network traffic at just under 5% when streaming to the HD300 and streaming from the HdHomeRun simultaneously. The CPU utilization at the same time was <4% give or take. When not streaming to the HD300, the network traffic (recording only to disk) was a bit over 1% from the HdHomeRun traffic -- all on a Gigabit connection per Windows.

Now, interestingly enough I did see a disk error last night at one point that Sage thew up indicating a file was not available when I told it to switch channels while watching live TV.. A second try and it worked OK...

If I ditch the current hard-drive, I'll probably move to something much larger -- any suggestions on size or brand would be appreciated.. I gather I probably want a 7200RPM drive.. I see various references on the forums here to people using the Western Digital Green drives -- are those about as good as any out there? I'm thinking that moving to a 2Gb HD might be about as good as I'm getting for a SATA 3Gb/second interface which is what this machine has.

Also, if I move to the new drive I'll likely move from Windows 7 back to XP Professional since I own XP media/license and not W7 (it came pre-installed on the new-to-me PC) -- is that a bad suggestion or should I bite the bullet and get W7 (if so, which one?)..

Thx!

[Fuzzy]

No, there's no need for a 7200RPM drive. In fact, you'll get far better performance using 2 cheaper 5400 (or even slower 'green' style drives) than you would a single 7200RPM. The bitrates needed for sage are really not that high, but they are high enough that if a section of a drive is iffy, and it takes a few re-reads to get a satisfactory CRC check, then it will run out of buffer, corrupting recordings, and halting playback. Seek times are significant, especially with just a single drive (think recording to two different files, and potentially playing back from a few different files). this is where multiple drives will help (sage will spread the recordings between the drives, lessening the seek impact).

[osx-addict]

Originally Posted by Fuzzy

No, there's no need for a 7200RPM drive. In fact, you'll get far better performance using 2 cheaper 5400 (or even slower 'green' style drives) than you would a single 7200RPM. The bitrates needed for sage are really not that high, but they are high enough that if a section of a drive is iffy, and it takes a few re-reads to get a satisfactory CRC check, then it will run out of buffer, corrupting recordings, and halting playback. Seek times are significant, especially with just a single drive (think recording to two different files, and potentially playing back from a few different files). this is where multiple drives will help (sage will spread the recordings between the drives, lessening the seek impact).

So.. If I can read between the lines, it might be OK to leave the existing (internal) drive in place for the OS and get an external enclosure with perhaps 4 or more drives and connect that via USB or SATA (SATA preferred I would assume)? Perhaps something like (but perhaps cheaper than) this which for me would also entail buying a eSATA card since this PC does not have any external SATA interfaces?

[Fuzzy]

For something that very likely will hide away in a closet somewhere, I see no reason to buy expensive external drive cages. Just buy an ugly, el-cheapo PC case with a lot of drive bays, and if you need to sata slots, a cheap 4-port sata card.

[osx-addict]

Originally Posted by Fuzzy

For something that very likely will hide away in a closet somewhere, I see no reason to buy expensive external drive cages. Just buy an ugly, el-cheapo PC case with a lot of drive bays, and if you need to sata slots, a cheap 4-port sata card.

That thought had crossed my mind after writing the previous post.. Thanks!

[osx-addict]

Ok.. Minor update.. I went to the local Fry's and bought a WD Green Caviar drive -- 2Tb in size and replaced the original 320Gb drive with this new one (SATA). I formatted (which takes FOREVER BTW!) the drive with NTFS using XP Pro (SP1) and eventually got the OS up to snuff in terms of Service packs and 1001 patches. I finally installed the HdHomeRun software + Sage v7. Once I got it setup with the tuners, I tune the HD300 to channel 2 and viola -- same crap as before.. Ugg!

So in more playing with different channels, I see the same sort of green snow artifacting issue (which in some cases may take up almost 1/2 of the screen) -- mostly when watching channel 2 (CBS) but I also saw it on 4, 5,9 and 11 among others.

So, apparently it is NOT an HD issue -- unless it doesn't like the interface it's plugged into.

So, as of now the machine is running XP Pro SP3 with all of the latest patches as of last night, with firewall enabled but no antivirus -- only Sage & HdHomeRun s/w installed. Could this be some sort of power management issue with Windows? Or perhaps, could it be that it is being caused by the integrated Intel Pro/1000 Gigabit ethernet interface on this machine? I do have some PCI based Intel ethernet interfaces lying around that came out of some older Proliant servers I've got -- they may not be gigabit though..

I did run the Task Manager and saw even less CPU/network usage than I was seeing on Windows 7 -- network was 2-3% usage and CPU was <4%.. Seems like the CPU (1.86Ghz core 2 duo) is plenty for this task.. I'm kinda leaning towards some sort of issue with the ethernet interface.. I've got the machine plugged into the EXACT same ethernet drop as the older Powermac G5 was, which worked fine.

Either that or it is an issue with Sage v7 (since I was using SageV6 on the Mac)

Any suggestions?

[gplasky]

So the HDHomeruns has it's own standalone software and the capability of tuning and playing in Window Media Player, VLC and their own QuickTV interface. Is the quality you're seeing in the Sgae the same as in any of those players? If it is it is probably a signal issue. And maybe not so much signal strength but the quality of the signal may be low. Both can be measured in the SiliconDust utilities/setup software.

Gerry

[osx-addict]

Originally Posted by gplasky

So the HDHomeruns has it's own standalone software and the capability of tuning and playing in Window Media Player, VLC and their own QuickTV interface. Is the quality you're seeing in the Sgae the same as in any of those players? If it is it is probably a signal issue. And maybe not so much signal strength but the quality of the signal may be low. Both can be measured in the SiliconDust utilities/setup software.

I have great signal strength on the TV side.. In fact, the antenna is currently split before the HdHomeRuns take their tap and the signal goes to a pair of DirecTV HR10-250's which see NO issues with the same channels. It's definitely the Sage installation -- the same HdHomeRun's when talking (via ethernet) to a SageTV (v6) installation on the PowerMac G5 plugged into the same network drop runs fine with no issues.. It's something on the PC.. I was hoping a fresh install of XP Pro + new hard drive would solve the problem but not so..

[osx-addict]

Ok.. Some fuel for my issue I think.. I ran across this thread that seems to indite the Intel ethernet controller mounted on the system board as the culprit -- caused by (more than likely) a reduction in solder used to put the motherboards together.. IF anyone else has issues like this and happens to be using an older HP DC7700 or DC7800 you may have this issue..

I think I'll try a PCI based controller and see if it behaves better..

[osx-addict]

Ok.. Just to followup on my own post.. The above mentioned thread on the HP forums appears to be correct.. I went to my local Fry's and picked up a small PCI Gigabit ethernet adapter (don't recall the make -- I think it was Linksys).. I installed it in the lone PCI port on this particular machine and proceeded to boot the machine and load the drivers.. Anyway, after everything was setup and the network was working, I proceeded to test the issues I was having again.. In playing the same channels that were problematic with the motherboard mounted ethernet adapter, they were no problem for this new adapter..

On top of that, the overall network usage dropped (to about 1/2 of 1%) and the CPU usage also dropped by several percent down to 2-3% tops.

Overall a great fix and it's working like a charm now! This setup is barely taxing the 1.86Ghz Core 2 duo processors.. But I've not yet plugged in the comskipper..

[Serra]

I had the exact same issue. A new card fixed most of my issues, though I did find out later that I had a small signal issue that I couldn't see as the original issue was so much of a problem, the smaller issue was masked.

Comskip could be an issue, just make sure isn't running too many instances. I can safely run one per device.