Choppy video with USB1.1?

[digitalabsolute]

Hi.

I am running SageTV (2.2.8 I believe) on a laptop top with the following specs, but it is giving me choppy video and sometimes crashes when I am viewing it with the guide and video.

AMD Athlon 1800+(1.5Ghz)
512MB RAM (448 after video)
64MB Shared video ram on ATI Mobility U1 (IGP 320)
WinTV-PVR-USB2 through USB 1.1
5400RPM 40GB HDD

Now, I have tried other apps, like MEedio and BeyondTV and they are stuttering similarly. I set the encoding rate to Fair to keep the bandwidth as low as possible, but it didn't seem to help much.

What I am wondering is will a USB2.0 hub fix this or is it likely the 5400RPM hard drive? And if so, would grabbing a USB 2.0 PCMCIA card and an external 7200RPM drive make everything work sexily?

Thanks in advance for the help.

Also of note: Regular video playback works fine even to network folders. Never a hiccup, even when viewing them in conjunction with the guide.

Help? ^_^

[Kanati]

USB 1.1 I think only has 11 mbit total throughput, and that isn't guaranteed. I would be on that being the problem. The 5400 rpm drive certainly doesn't help matters but I think it's probably fast enough.

Try getting yourself a 2.0 PCMCIA card and see if that helps first off... Then if it doesn't, try adding the 7200 rpm external.

The other specs on the laptop seem to be fine though.

[Opus4]

If the part of the drive used for recordings isn't formatted with 64K cluster sizes, you can easily have stuttering problems for recording and/or playback. I would check that first.

The PVR-USB2 is supposed to work at lower recording rates using USB 1.1, but I would try to stick to USB2 with it.

- Andy

[digitalabsolute]

So it needs to be 64k cluster sized? Standard NTFS is 4k, right? Because it is just a normal NTFS format right now.

Why is that the case, if I might ask? Less physical disk processing? Also, when changing it to a 64k cluster size, should I set it off from the Windows drive or will windows still run fine with the 64k size?

[Opus4]

You can make the whole disk have 64K clusters, but the OS partition doesn't really need it. What many people do is set up a partition just for storing media & use 64K clusters only for that one.

The problem w/4k clusters is that the drive simply cannot keep up with the data throughput requirements -- especially when fragmented, it can't seek to a new location fast enough to keep up with the amount of data that it needs to read and/or write every second. With 64K clusters, it doesn't have to seek nearly as often, so it isn't usually a problem.

- Andy

[digitalabsolute]

Thanks. I'll run it through Partition Magic later.

I still plan to get a USB2.0 adapter so that I can later get an external drive. Are there any reported problems going from a USB tuner to a USB HDD? (That's my last question, I promise)

[Kanati]

USB 2.0 has something along the lines of 480MBit of bandwidth. It should be able to handle anything you throw at it in regards to sage.

[digitalabsolute]

Thanks! Now if time would only speed up so I could get off work to go see if the bigger clusters fix the video issue.

[steingra]

I have a 2.0 USB hub, and a PVR-USB2 device connected to it. It works fine @usb 2.0 rates. I also formatted my hard drive using 64k block size(i have separate drives in Raid array with the 64k block size just for videos) and OS in on IDE drive,

And I do not experience choppy video/audio problems.

I hope upgrading to a 2.0 hub will fix your problem.

PS if you need a good usb troubleshooting tool check this one out. I like it a lot http://lpt.usbfireinfo.com/USB_Info_...o_software.htm

I bought a copy. Since I have sooo much hooked up to the HTPC now.

[Kanati]

Just adding a 2.0 hub will do nothing if the computer is still at 1.1... PCMCIA card with a couple 2.0 connectors will be what he needs.