After enjoying KnoppMyth in my living room for so long, I've decided to branch out into making a frontend for my bedroom. I had a round of upgrades recently, so there's a spare PC.

I set it up, get it booting and all looks fine. Then I go to play a show, and it pauses a beat every 3 seconds. I'm using an oldish (10 years?) 100bT hub, that's served me very well. I know I've read of people saying 100bT is fast enough to handle streaming recordings. I started with just running the frontend off the CD, I noticed it only used the nv X.org driver. So I installed to the hard drive. It then used the nvidia driver, but it still skipped during playback. I don't have anything else using the network when I try this stuff.

So, my question is, are switches that much better? I've thought about going to gigabit, but if there's some settings on how much the frontend buffers up or something I can set for free, that'd be super.

Hmm, I just fed a file to VLC in Windows, and it plays without skipping a beat. So I guess it's something with my frontend still. Back to the drawing board...

After a little more testing, the network is ok. Mplayer can play SD streams (from a PVR500) without skipping a beat. So, the stutter is somewhere in the frontend's player.

Just for your info, the basic explanation of the difference between a Hub and a Switch, is that a Hub shares the bandwidth across all the connections, whilst a Switch dedicates bandwitdh to each port.

I.E. With a 100MB Hub, you only have 100MB of bandwitdh across all ports. A 100MB Switch you have 100MB per port.

_________________
Girkers

100Mb Hub vs 100 Mb Switch.

Collision Domains and Full Duplex traffic
With a 100 Mb hub all of the ports are in the same collision domain and seems directly connected to each other. Hence linmited traffic and you can't get a Full Duplex, Bi Directional traffic flow. Which ever traffic gets there first has the domain and everybody else waits a random fallback time to attempt a transmit again. While each port gets 100 Mb they typically randomly compete sharing the bandwidth. And then that multiple access to a single collision domain comes in. All network devices and machine o/s have a bit of keep alive traffic.

With a 100Mb switch, each individual port is able to attempt to send traffic. They all can be attached in a Full Duplex fashion effectively acheiving 200 Mbps traffic 100 up and 100 down. Most switches have a little bit of intelligence to segment the traffic on the Wan side of the switch so every Lan port gets what it believes is 100 Mb bandwidth. This allows all lan ports to effectively achieve 100 Mbps Full duplex bandwidth.

Of course, if you have multiple devices sending 100 Mbps traffic at the same time, the Wan port can only handle 100 Mbps in each direction so you will still see limitations but I don't believe you will fill that with a couple of interactive myth streams.

I am not sure why anyone would by a hub, when there are inexpensive gigabit switches out there. Naturally, you would need gigabit adapters for these switches, however, I suspect that the "floor" these days for adapters is 100MB.

_________________
R7.3: 0.22.20091023-1, Hauppauge PVR-500 (Philips FQ1236A MK4), Gigabyte Gigabyte EG45M-UD2H, E5200 2.4Ghz, 2GB RAM, NVIDIA GEFORCE 256MB

Hmm, I'm still playing around with this. I remembered I had a laptop in the closet, which I broke the LCD screen. So I pulled it out. It has Kubuntu installed, and I download the latest mythtv-frontend for it. It pulls up all my shows perfectly, not stuttering or anything. It would make a great frontend, except it has an ATI chipset, so the TV-out isn't working.

This still has me puzzled as to why KnoppMyth's mythfrontend has this behavior. This laptop connects and plays with the myth backend just fine, and mplayer of the MPG file (PVR500 recording) over NFS works fine on KnoppMyth.

Maybe I'll go through each of the setup configs and see if anything is different...

I am not sure if you're system is 10MBS or 100MBS, however, I would be surprised if you had problems even on a 10MBS if you are playing .avi files.

_________________
R7.3: 0.22.20091023-1, Hauppauge PVR-500 (Philips FQ1236A MK4), Gigabyte Gigabyte EG45M-UD2H, E5200 2.4Ghz, 2GB RAM, NVIDIA GEFORCE 256MB

<pedantic>
In _theory_ a switch can have 200MB of bandwidth per
port if full duplex. However, the switch fabric inside the box
also has a maximum total bandwidth it can handle. For many
first generation, low-end consumer grade switches with N ports,
the max switch fabric bandwidth is less than N*200MB (often
even less than N*100MB). That said, even the cheapest switch's
total bandwidth capacity is going to be way better than a hub,
but it may not to be able to handle 200MS (or even 100MB) per
port on all ports simultaneously.

Most of the "brand name" vendors will actually specify the
switch fabric bandwidth, and then you can tell if it can run
all the ports at 200MB or not. Some of the cheaper brands
don't spec a switch fabric bandwidth, so you don't really know
(though I suspect most of the 10/100 stuff that's being shipped
today can max out all the ports).

Unless you've got a whole rack of HDHomerun's this is pretty
much all academic for a MythTV installation...
</pedantic>

_________________
Grant

grante,

Thanks for that tidbit of info. I will be looking at investing in a Gigabit switch very soon, so I know exactly what to look for now.

_________________
Girkers

With some hit-and-miss playing of videos on the system, I picked up some new parts to replace in this system. It had an Athlon-3000 (Socket A) CPU, which was my KnoppMyth backend and frontend when I started, back around R5A* series. I had since upgrade the backend with faster parts when I got a HDTV.

I expected everything to work just fine when I resurrected this system out of the storage closet. Unfortunately, I ran into these frustrations. I assumed the network couldn't keep up, as it was my main system long ago. Anyway, I had a Socket 939 motherboard and Athlon64 3000+ CPU lying about, so I had to spring for a new PCI-Express video card and upgraded this system. Thus far, it's working ok. The 100Mb hub is holding up for the couple shows I played. One of these days I'll get a switch, gigabit maybe. We'll see... I am puzzled how this system couldn't handle playing the shows when a year+ ago, it did it just fine. Ah well.