HD300 ff / rewind jumpy?

[drewg]

I recently replaced my HD100 with an HD300. It is so much better in almost every way. However, there is one small annoyance that I noticed. When I skip or jump forward or back in an HD Mpeg2 recording (ATSC), there is a small hiccup when playback resumes. The video starts, then pauses for a split second, then resumes. Anybody else noticing this? It doesn't seem to happen on low bandwidth (SD) recordings.

I'm running the HD300 in client mode, against Server 6.6.2 running on a linux server. I never noticed this on the HD100..

Drew

[AzTech]

I see the same thing running the lastest beta, 7.0.16 on Windows 7. I get it on HDHR recordings and HD-PVR recordings. It is a very quick stutter/pause about a second after ff or rewind is pressed. Playback is smooth after that. This is only on the HD300. HD100 playback is fine. It is sort of annoying but I can live with it.

[drewg]

Originally Posted by AzTech

I see the same thing running the lastest beta, 7.0.16 on Windows 7. I get it on HDHR recordings and HD-PVR recordings. It is a very quick stutter/pause about a second after ff or rewind is pressed. Playback is smooth after that. This is only on the HD300. HD100 playback is fine. It is sort of annoying but I can live with it.

Check your network.. Yesterday, I noticed that blurays were behaving very badly (lots of little hiccups) and I decided to investigate. After fixing the underlying network issues by disabling ethernet flow control, bluerays are smooth, and I think my ff/rew glitches are gone. Details:

I downloaded the Codesourcery mips SDK and built some network benchmarks for the HD300 (iperf, netperf). I found that unless I used very careful TCP tuning parameters (reducing socket buffer / window size to between 8K and 16K), performance was abysmal. I was seeing 25Mb/s from my server to the HD300. Other machines on my wired network were seeing 94.5Mb/s to the HD300.

I have a Dlink 8-port "Green" 1GbE switch, with my server and the HD300 plugged into it. My server uses an Atheros L1 NIC. Machines that worked fine used Intel 1GbE NICs, or the Nvidia MCP 1GbE on-board NIC. I noticed that all machines got a lot of ethernet flow control (pause) packets when talking to the HD300. Since the switch is unmanaged, I could not disable flow control on the switch. After playing with some settings on the sever's NIC, I finally managed to disable flow control, and the speed increased by a factor of 3.5 (25Mb/s -> 94.5Mb/s).

I'm surprised I never had this issue with the HD100. I guess it must have either used a different TCP window size, or it never managed to open the TCP window enough to cause the switch to assert flow control. No surprise, since the HD100 was running a much, much older version of linux.

Drew

[AzTech]

I'd been working with Sage support to get another issue with stuttering with DVD's resolved and that did turn out to be an issue with a switch. I was hoping along with replacing that switch, the quick pause/stutter after skip ff/rew would also go away. Unfortunately, I wasn't so lucky. Based off your solution, I obviously have other network issues I need to address. The HD300 sure is a lot more finicky than the HD100. Thanks for the update!

[drewg]

Let me know if you want my iperf or netperf binaries..

Drew

[crarbo1]

Originally Posted by drewg

Check your network.. Yesterday, I noticed that blurays were behaving very badly (lots of little hiccups) and I decided to investigate. After fixing the underlying network issues by disabling ethernet flow control, bluerays are smooth, and I think my ff/rew glitches are gone. Details:

I downloaded the Codesourcery mips SDK and built some network benchmarks for the HD300 (iperf, netperf). I found that unless I used very careful TCP tuning parameters (reducing socket buffer / window size to between 8K and 16K), performance was abysmal. I was seeing 25Mb/s from my server to the HD300. Other machines on my wired network were seeing 94.5Mb/s to the HD300.

I have a Dlink 8-port "Green" 1GbE switch, with my server and the HD300 plugged into it. My server uses an Atheros L1 NIC. Machines that worked fine used Intel 1GbE NICs, or the Nvidia MCP 1GbE on-board NIC. I noticed that all machines got a lot of ethernet flow control (pause) packets when talking to the HD300. Since the switch is unmanaged, I could not disable flow control on the switch. After playing with some settings on the sever's NIC, I finally managed to disable flow control, and the speed increased by a factor of 3.5 (25Mb/s -> 94.5Mb/s).

I'm surprised I never had this issue with the HD100. I guess it must have either used a different TCP window size, or it never managed to open the TCP window enough to cause the switch to assert flow control. No surprise, since the HD100 was running a much, much older version of linux.

Drew

Originally Posted by drewg

Let me know if you want my iperf or netperf binaries..
Drew

Drew,
Thanks for the information. I'm having issues with my setup and your solution may help me. I was wondering what settings you changed on the servers NIC that disabled flow control. In any event, I'm interested in your binaries if you can let me know how to use them effectively.

Thanks,
Chuck

[drewg]

Originally Posted by crarbo1

Drew,
Thanks for the information. I'm having issues with my setup and your solution may help me. I was wondering what settings you changed on the servers NIC that disabled flow control. In any event, I'm interested in your binaries if you can let me know how to use them effectively.

Thanks,
Chuck

It was pretty linux-specific. The atl1 driver was broken, and it was impossible to disable flow control via ethtool. So I had to use miitool to disable flow control.

I'll PM you with a URL for the binaries, and directions.

Drew

[crarbo1]

Originally Posted by drewg

It was pretty linux-specific. The atl1 driver was broken, and it was impossible to disable flow control via ethtool. So I had to use miitool to disable flow control.

I'll PM you with a URL for the binaries, and directions.

Drew

Go ahead and send me the URL, if it will work work windows. I didn't know you were using Linux but if the tools work, then I may be able to figure it out.

Thanks,
Chuck

[heffneil]

I have noticed that while playing shows and during playback of recordings there is a lot of jumpiness. I thought it was an effect on the show until my wife said this isn't right. If I pause it will "catch up" and stop the jumpiness. I tried disabling dirmon2 and it didn't really help the situation...

[AzTech]

Don't know if others have this happening, but the beta firmware released yesterday fixed this problem for me.