HTPC CPU/RAM requirements on a per channel basis

[xpsd300]

Hello,

I'll be building a Windows 7 Pro 64-bit HTPC as a whole house solution so that six TVs will continue to work without individual set-top boxes after the all-digital transition in my area (this summer), and so that I can replace obsolete VCRs with a centralized DVR.

My current setup is:

- RG6 quad shield from cable co. box to 8-port cable co. amplifier (Extreme Broadband IPA1008D-RSVF)
- Passive port on amplifier to cable modem (-3.5 dB) via RG6 quad shield
- Amplified ports to eight drops (0.0 dB gain/loss) via RG6 quad shield
- RG6 quad shield from six drops directly to TVs (no set-top boxes); unused drops capped off

I also have a 16-port gigabit switch (Netgear GS116E-200NAS) to share high speed Internet, with at least one CAT6 drop nearby each TV location.

I plan to use two SiliconDust HDHR3-CC tri-tuners with cable co. CableCARDs (and tuning adapters, if required for expanded basic service), five Ceton Echo 6100-MCX extenders, and have one TV connected directly to the HTPC. The tri-tuners (and tuning adapters) will be connected directly to the amplifier so that splitters are not necessary.

I looked at the Ceton InfiniTV 6 devices, but I'm leaning towards the SiliconDust products due to quicker channel switching and proven compatibility with my cable co. (Charter Communications).

Here's where I need some advise. From my research, it appears that the minimum system requirements are one processor core and 2GB of RAM for each active extender. However, I've found very little information on system requirements on a per channel basis.

For example, live TV is typically watched on no more than three of our six TVs simultaneously (each of which would need to be connected via an extender). However, three additional channels are usually being recorded at the same time.

How does Windows Media Center process individual channel requests? Is the CPU/RAM usage the same to record live TV (in native .wtv format) as it is to stream live TV or media files to the extenders? How about when live TV is watched on the HTPC via its HDMI output?

Also, what is the typical CPU/RAM usage to transcode to a smaller size or rip a blu-ray disc on a per file basis? I don't foresee doing this normally during peak TV watching hours, so I would prefer not having a dedicated transcoding system or NAS device.

Given these factors, should I consider a six or eight-core processor? Are there any lower-watt CPUs that would meet my needs and also keep fan noise to a minimum?

Thanks.

[gthompson20]

You can only have 5 extenders connected at one time per Windows Media Center PC.

Edit, Sorry read that as 6 extenders above, since you said 5 you should be ok... Sorry!

Greg

[xpsd300]

I forgot to ask about connecting the Ceton Echo to a CRT TV (three of our six TVs).

According to their blog, http://cetoncorp.com/blog/more-details-on-ceton-echo/:

For people who want to connect Echo to a TV that doesn’t have HDMI input, the Echo will work with an HDMI to Component or Composite converter.

I contacted Ceton tech support about this, but they couldn't give me the models of any compatible HDMI-to-Composite converters. They did, however, state that ones which require a USB power plug could be powered from the Echo unit via its USB port.

This one seems to fit the bill -- CVID BG-450 (and is one of the few shipped and sold by Amazon). Any thoughts?
http://www.amazon.com/dp/B00987MWAM

[barnabas1969]

You got the RAM requirements wrong. You need 2GB plus 1GB per extender. So, for 5 extenders, that's 7GB. Since you can't buy a 7GB RAM module, you'll need to buy 8GB.

Also, I recommend the XBox360 instead of the Echo. It will do composite video just fine right out of the box, and works MUCH better than the Echo could ever hope to work.

And there is no "per channel" requirement for RAM or CPU. All of the CableCARD tuners available have on-board hardware decoding, so there is almost no load on the CPU or RAM. If you buy other types of tuners, just make sure to get ones with hardware decoding on the board.

[xpsd300]

You got the RAM requirements wrong. You need 2GB plus 1GB per extender. So, for 5 extenders, that's 7GB. Since you can't buy a 7GB RAM module, you'll need to buy 8GB. And there is no "per channel" requirement for RAM or CPU. All of the CableCARD tuners available have on-board hardware decoding, so there is almost no load on the CPU or RAM. If you buy other types of tuners, just make sure to get ones with hardware decoding on the board.

Thanks for the clarification.

So for the worst case scenario -- one directly connected TV and 5 extenders operating simultaneously -- I should consider at least 8GB RAM and a six-core processor. Also, if I understand you correctly, these specs should also have no trouble recording six channels at once on the HTPC, or any combination of streaming live TV or recording. Is that right?

Would this CPU/RAM combo be sufficient for transcoding?

Also, I recommend the XBox360 instead of the Echo. It will do composite video just fine right out of the box, and works MUCH better than the Echo could ever hope to work.

If I go the XBox route, the XBox 360 E looks promising. Would the 4GB model be sufficient if used just as an extender?

[IownFIVEechos]

You need to use the XBOX that came before the E which was the S I think. 4GB version will work fine. The latest version only has the HDMI not the connections you want (no AV port or toslink for audio); you would need to invest in additional hardware see post below. Good luck.

Edit: did some reading on it, sounds like the picture quality is horrible either way on composite.

http://forums.xbox.com/xbox_forums/xbox ... 48900.aspx

[xpsd300]

You need to use the XBOX that came before the E which was the S I think. 4GB version will work fine. The latest version only has the HDMI not the connections you want (no AV port or toslink for audio); you would need to invest in additional hardware see post below.,

I believe the 360E does have an AV port which uses an 1/8in-to-Composite AV cable (bottom right):




As for picture quality, the composite output would only be used on a few standard def CRT TVs (largest being 32"), so I don't believe the quality would be any worse than using the RF connector input on the TV as I am doing currently (no set-top box).

[barnabas1969]

The S and E both have composite outputs. Both come with the breakout cable that has composite video, and stereo audio. The E does not have an optical audio output, so if you need that... then get an S. The 4GB models work fine.

You don't need a 6-core processor. Any recent quad core i5 will do just fine. See the following link for my build. It will support 5 extenders with no problems at all.
http://www.thegreenbutton.tv/forums/vie ... f=7&t=5587

As for recording... it is almost all disk I/O. See my build (link above). That system has 10 tuners attached to it, and I can run all my tuners and all my extenders simultaneously... and the HDD doesn't even come close to being overloaded.

[barnabas1969]

I suppose I should also comment about the quality on a standard-definition TV. I haven't tried using an XBox with a composite output, but I would imagine that the quality is similar to using a Linksys extender with the composite output. I have done that on a 20" SDTV. The video quality was just as good as any other SD video source when watching recorded/live TV.

However, the text on menus was not easy to read on an SDTV. It was usable though.

[xpsd300]

@barnabas1969 Thanks for all of your assistance and for providing me with a proven parts list that will provide room to grow with my proposed setup.

I especially like the case you went with and the LED functionality. Can you explain a little more about the parts needed to control the LEDs?

I did a lot of mods last year for a Xeon workstation build, so I'd be up to the challenge.

[xpsd300]

I re-read your post and found the product you're using:

LEDSdriver
http://slicksolutions.eu/ledsdriver.shtml

[barnabas1969]

Yep... the LEDSdriver software plus some LED's and resistors is all you need. I used 330 ohm 1/8 watt resistors in series with the LED's. I soldered them onto a bread board that I bought at Radio Shack, and used an old cable from a case that I threw away. It was the cable for the front USB ports. I changed the pin configuration on the cable to match the pinout shown on the Slick Solutions website. Then, I just soldered it to the bread board and soldered the resistors and LED's. The other end of the cable that normally plugs into a USB header on the motherboard was plugged onto the RS-232 header on the motherboard. I had to drill out the "key" in the plug which normally lines up with the missing pin on a USB header so that it would plug onto an RS-232 header instead.