CPU and Network utilisation with DVBLink network tuners

In my previous post Why all the excitement over network tuners? I went into what DVBLink can do and why I think this is so great for the Windows Media Center (WMC) enthusiast. I said I would do a follow up post showing the CPU and network utilisation and this is exactly that. I would emphasise that these are taken from my live Windows Home Server (WHS) so there are spikes in the CPU graphs as normal WHS process start and stop (I’m also running a virtual machine on my WHS which also causes CPU spikes.

This is the hardware in my WHS which is very similar to our HTPC since the parts were mostly cheap:

  • Motherboard: ASUS P5LD2-VM
  • CPU: Intel Celeron D 352 3.2GHz
  • RAM: 2GB of memory (Corsair TWIN2X1024A-6400)
  • 2 x Hauppauge Nova-T-500 PCI Hybrid Dual Tuners

When you install the DVBLink software this adds some virtual tuners which you can see here along with the two Nova-T-500 physical tuners:

Device Manager showing DVBLink virtual tuners & Nova-T-500 physical tuners

As I have the two dual tuners this gives me a pool of four that can be used by the other computers on the network. When you have these configured you can use Windows Media Player (WMP) or any other UPNP complient media player (PS3 for example) to view live TV.  If you want to use WMC on the client then you install the DVBLink client onto the computer and you get the same virtual tuners added into device manager.

I’m going to get all four tuners recording and will show the CPU and network utilisation as I increase the number of channels being recorded. I’ll start off by showing the WHS without any live TV or recording active:

CPU & Network utilisation with no live TV or recordings

Now I’ll start recording one channel at a time to show how the CPU and network utilisation changes:

CPU & Network utilisation with one recording active

CPU & Network utilisation with two recordings active

CPU & Network utilisation with three recordings active

CPU & Network utilisation with four recordings active

I thought I’d also include a screen grab from WMC showing all four recordings active:

WMC with BBC1, BBC2, ITV and Channel4 being recorded on my desktop

I believe that these figures are low, especially the network utilisation, and when you consider that the CPU in my WHS is an old Celeron single core that 40% when recording four channels is good. I do think that those running low powered Atom based servers might have some issues. Anyone that has a Core2Duo or newer CPU would no doubt see less CPU useage. There is also an option in the release candidate to use RTP instead of UDP for slower network connections. I should stress that all these are based on standard definition DVB-T sources. It would be great if someone could provide information on high definition useage.

Hopefully this gives people an idea of the CPU and network requirements when using the DVBLink network tuner software. I haven’t included details of the client since apart from the network useage WMC is working the same as if the tuners were physically installed so I’d expect the same CPU & disk I/O as you are used to on your HTPC. Please ask any questions using the comments or you can follow me on Twitter.

5 thoughts on “CPU and Network utilisation with DVBLink network tuners

  1. THis looks fantastic, and would suit my needs perfectly however i do have one concern regarding MCE like the Xbox 360 usage, for instance if your MC has 4 recordings going on at the same time using the DVB link and you are streaming say 2 live tv shows using built in tuner to the MC to an MCE like the 360 do you have any network congestion? Hopefully I am clear on this question.

  2. @pawtrski – I’m not sure I completely understand so let me summerise what I think you are saying. You have four network based tuners and two more local tuners giving you six tuners in total. You are recording four shows using the four network tuners. There are two Xbox360’s running as extenders to the Media Center PC and they are each watching a show each (so both local tuners are in use).

    I think that with a gigabit network only requiring 2% (so 20% of a 100mbit) to record 4 shows it should work fine especially as with the 4 recordings they will be pulling data into the PC and the two Xbox360’s will be taking data out.

  3. Hi JayC

    Registered to say thanks for this. I discovered DVBLink yesterday and it looks like the solution to my scenario – 3 Media Centers without TV cards, including one small dinky one, where I want to avoid buying multiple cards for each machine, wiring up the whole house etc. Now I’m just going to get freesat and slap some cards in my Media Center.

    I was worried about CPU usage, whether I’d need a GPU in my WHS etc if I use DVBLink but from your stats I can see I won’t and I’ve just upgraded my WHS to a i3 530 so I have a lot more power than you!

    Thanks also for clarifying how the virtual tuners get allocated – I was trying to work out what happened if all were in use and the use of a ‘master’ client makes sense to me.

    EB

  4. @Everton – No problem, thank you for taking the time to show your appreciation. Can I also recommend Garry’s excellent post here:

    http://thedigitallifestyle.com/cs/blogs/garry/archive/2010/01/20/dvblink-how-tuner-pooling-works.aspx

    If you have room in your WHS then the more tuners you add the better, the way DVBLink uses logical tuners (not to be confused with the virtual tuners that get added in device manager) means that the Media Center clients have access to more than 4 physical tuners. That along with the master setting can mean never having no tuner available.

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