HTPC backend and NAS

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berky

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I'm in need of a NAS system, but also want to eventually use it for my HTPC backend, so I want to dual-purpose the machine for NAS and HTPC storage.

So, I'm trying to determine my parts list, but wanted to run a few things by everyone to make sure I'm not completely off-base.


I have Comcast, but I'd like to not be limited to my current TV provider in case I change providers when I build a new house in a few years (or so is the current plan). I bring this up because I've read about some tuners that have trouble with certain providers' encoding schemes. I don't need a tuner right away, but if I do get one, I'd like it to be able to pick up any standard cable channel that a cable-ready TV could pick up by default. Eventually, I'd like to add another tuner with a cablecard for digital (This will not be co-located with any of the TV's)

Is PCI express x1 pretty much the standard for tuner cards?

For the case, i'm planning to do a rack-mount case like thus: http://www.newegg.com/Product/Product.aspx?Item=N82E16811321004
I don't have a rack yet, but I plan to eventually and I can make room easier for that type of case.

For the CPU, I was looking at a Athlon II X4. I was thinking this because of wanting multiple tuners. Is this overkill? sufficient? Assume that I may eventually want an HD tuner.

Motherboard - This is where most of my questions come in. I don't know if I want to set up something like RAID 5, or JBOD. for the OS, I was planning to install Linux on a CF card (like 8 gig or so) and run it off of that, then have the hard drives dedicated to data. I'm trying to think about the best way to set this up. I can get a mobo with onboard RAID, but will I lose the data if the mobo dies and i get another one? what if it's a different mobo? can i retain the data then? If I go with a RAID card, the cheaper one's I've found are PCI-X, so that basically limits me to a server mobo, which drives costs up. I was looking at this (http://www.newegg.com/Product/Product.aspx?Item=N82E16813130223) but it doesn't have any onboard video, so there's another cost. Plus it only has 1 PCI-e x1 slot, so I may be limited to to a single tuner. However, it was the only result in my search that had at least 8 SATA ports and did RAID.

moving on, how much RAM would be necessary if using 2 tuners? 1gig? 2? 4? what if I added a 3rd tuner long down the road for HD?

lastly, the HDD's.... I'm looking at the Samsung EcoGreen drives in 1.5 TB capacity since they are cheaper per GB than the 2TB drives currently. I've always had good luck w/Samsung, WD, and Seagate.

Final comment: I'm trying to make this thing with low power, but also powerful enough to do the tasks I need it to do. Knowing that this will only feed frontend systems across the network, I assume all of the decoding power will be necessary on the frontend, not this backend, correct?

Hopefully my questions make sense.

Thanks.
 
So I guess there aren't any biters on this one :p

let's start more simple.

do most of you split your front and back ends? or do you typically just have a single system that you use for both purposes?
 
Depends on who it's for. I am going to be building one for my parents here in a couple months and it will be one machine that does it all. Whereas if I were building one for myself I would have a server that all the shows get recorded on and use lower-powered computers to stream the media to my TV.

As far as processor requirements if you got a Athlon II X4 635 or better you will easily be sitting pretty. To be honest though you would most likely still be fine with a 3GHz dual core. I would also at minimum shove 4GB of ram into whatever machine you have doing the recording.
 
Man hopefully you haven't started buying anything yet. Didn't notice this thread earlier.

To answer your questions:
Yes PCI-Ex1 is pretty much the standard for newer TV tuner cards these days.

Case wise, never heard of that brand before. Generally see Norco or Supermicro when it comes to rackmount cases. From a price to performance perspective, it's ok.

CPU wise, that Athlon II X4 would be a tad overkill. But more on this in a bit.

Now for the biggies:
JBOD is probably not the best idea for a NAS.

It really depends on HOW that mobo dies whether or not the data is gone forever. With that said, assuming that your data is still intact after the mobo death, all you have to do is get a mobo using the same RAID controller. From there you can reactivate your RAID array and you'll be golden.

More than likely the PCI-X or cheaper RAID cards you're looking at are just software RAID cards. Which means that it won't be any faster than using Linux MDADM RAID. In addition, some of those PCI-X cards will work in a PCI slot.

Now is write performance and relatively low CPU usage important to you? I ask because most software RAID solutions have somewhat bad write performance (typically 35MB/s max for Windows, 60MB/s for Linux RAID) and constant CPU usage at all times. That constant CPU usage ranges from as 10% to as high as 60% depending on the size of array, CPU used, OS, and RAID type.

2GB of RAM should be enough. However if 4GB of RAM isn't that much more, go for it. More RAM rarely hurts.

HDD wise, have to get back to you on this.

And yes I split my front and back ends. Simpler, less complexity, etc, etc, etc,

Now a few questions from me before I can start recommending parts:
- What OS will your HTPC be using?
- How many hard drives do you plan on adding?
- What's your total budget for this NAS?
 
I have two HTPC's... one in the bedroom and one in the living room. The bedroom one has 2 * 1.5TB (3TB total) drives and the living room one has 2 * 2TB (4TB total) drives for a total of about 7GB (obviously less due to the 1024 is not equal to 1000 crap)... I will split my media over the two machines and both serve as NAS and HTPC.

Still haven't set it up completely yet and am learning along the way, but I think it'll work for me... then, come Summer... I'll need to think of a backup plan (maybe an HP Home Server with a crapload of empty space).
 
Danny,

no, i haven't bought anything yet. i'm still researching.

in regards to the RAID, are you saying that if I set up software raid through the OS, and the mobo dies, I can reuse any mobo with enough ports and the software will still be able to read the raid array? If so, that's what I want to make sure I do. I want to be able to recover data if any 1 piece of hardware fails.

to answer your questions

- I plan to use Linux w/MythTV
- I haven't entirely figured this out yet, but I'd like to rip my DVD collection and store it
- no real budget, but don't want to overspend on anything I don't need (looking at 800 max including HDD's, but prefer to stay below 600 if I can start with 2 or 3 hard drives and expand later)


edit: also note that I'm not planning to have much more than a NAS system at first, which is what my budget is listed for. Other addons later down the road aren't included, such as the Tuners.
 
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berky said:
in regards to the RAID, are you saying that if I set up software raid through the OS, and the mobo dies, I can reuse any mobo with enough ports and the software will still be able to read the raid array? If so, that's what I want to make sure I do. I want to be able to recover data if any 1 piece of hardware fails.
Click to expand...
I wasn't saying that at all. I was saying if you set up software RAID through the motherboard, and the mobo dies, you can use motherboard that uses the same RAID controller or a newer version of it to reactivate the RAID array.

But you are right: If the RAID array is created via Linux MDADM, you can move that RAID array to another motherboard if the mobo dies. However you have to make sure that the drives are installed the same order as they were with the old mobo and that the OS is set up more or less as the OS used for the RAID array.

berky said:
- I haven't entirely figured this out yet, but I'd like to rip my DVD collection and store it
Click to expand...

Well how big is your DVD collection? Will this be a straight rip or will you be re-encoding the DVDs as smaller video files?

Also you didn't answer this question:
Now is write performance and relatively low CPU usage important to you? I ask because most software RAID solutions have somewhat bad write performance (typically 35MB/s max for Windows, 60MB/s for Linux RAID) and constant CPU usage at all times. That constant CPU usage ranges from as 10% to as high as 60% depending on the size of array, CPU used, OS, and RAID type.
Click to expand...
 
Thanks.

I have approximately 100 movies and so far only 1 blu ray (which will change once the LOTR ext trilogy is out on BR). I will most likely re-encode the videos to smaller files while keeping high quality.

The only thing in terms of CPU usage and write performance that I care about is the ability to be able to record potentially 2 standard def tv shows at the same time. I plan to use a hardware encoding tuner so that shouldn't tax the CPU at all, it would just be writing the bytes to the drive.

and, i would prefer it to use as little electricity as possible while still meeting the needs of the system.
 
i noticed you mentioned you were planning to run two tuner cards in one box? while i have no reason to suspect this WOULDN'T work, i've just never seen it done.

also, i did some looking around and found this; http://www.newegg.com/Product/Product.aspx?Item=N82E16813136053&cm_re=ich10r-_-13-136-053-_-Product

ich10r and 8 sata 3gb ports. perhaps something like this might make for a better solution than software raid? it does put you in lga775, though. i can't say i'd be entirely confident in raid 5, but raid 0/1/0+1 should all be quite solid
 
berky said:
Thanks.

I have approximately 100 movies and so far only 1 blu ray (which will change once the LOTR ext trilogy is out on BR). I will most likely re-encode the videos to smaller files while keeping high quality.

The only thing in terms of CPU usage and write performance that I care about is the ability to be able to record potentially 2 standard def tv shows at the same time. I plan to use a hardware encoding tuner so that shouldn't tax the CPU at all, it would just be writing the bytes to the drive.

and, i would prefer it to use as little electricity as possible while still meeting the needs of the system.
Click to expand...

Will you be re-encoding the videos on the server or on your main PC and then moved back onto the server?
 
I don't think you need to worry about write throughput as long as you're using at least a single drive manufactured sometime in the past decade.

I have personally used several different 7200RPM drives with vintages ranging from 2006-2009 to record 6 shows at the same time - 4 of them HD, 2 of them SD (hardware encoder).

When you do the math on the throughput needed for that, its really not that bad....

<quick math>
4x HD streams @ 10mbit (assuming 720p)
2x SD streams @ 2mbit

44mbit/sec total write needed

8 bits = 1 byte, thus,

44mbit/sec = 5.5MB/sec
</quick math>

From a CPU perspective, the above 6 streams were recorded using an Athlon X2 3800+, which _maybe_ hit a 10% CPU utilization while recording, playing back a show and playing one back over the networkt o an extender. The only thing a faster CPU would do would be to speed up the transcoding, shrinking and commercial processing that is done, but I schedule that for at night when its not being used. This was with 1GB of ram in the system (full specs in my sig)

If you want to be able to utilize cablecard in the future, right now, that future means you'll be running Windoze 7 MCE. Unless the FCC lays down the smackdown with new cablecard rules, this is your only option as I'm quite sure that Cablelabs will never certify MythTV as legit software. Cablecard may require more processing power, as the guys over at Ceton (who are about to release a quad cable card tuner) have a quad core processor as their minimum specs (I presume some of the encryption and DRM tasks are offloaded onto the CPU). The other consideration should you go this way, is that anything you record that is marked as copy restricted, you will only be able to store it on the box that you recorded, and only view it on that machine or media center extenders. Other PC's are a no-go right now for viewing copy protected content (I hope in the future that the Vole allows other Windoze 7 MCE computers int he same homegroup to act as an extender).

Given that, your new setup might look more like a NAS/tuner box with extenders placed around the house.. though.. the only true extender left these days is the Xbox360....
 
SinShiva said:
i noticed you mentioned you were planning to run two tuner cards in one box? while i have no reason to suspect this WOULDN'T work, i've just never seen it done.

also, i did some looking around and found this; http://www.newegg.com/Product/Product.aspx?Item=N82E16813136053&cm_re=ich10r-_-13-136-053-_-Product

ich10r and 8 sata 3gb ports. perhaps something like this might make for a better solution than software raid? it does put you in lga775, though. i can't say i'd be entirely confident in raid 5, but raid 0/1/0+1 should all be quite solid
Click to expand...

I've only read about other people putting more than 1 tuner in a single pc. this is my first htpc setup, so i have to assume this is possible based on what i've read.

thanks for the mobo link. i've always been an amd guy and never really bothered looking at intel setups. for the right price and features, i have no issues switching.

i'm fine with either hardware or software raid, but I just don't want to pigeon-hole myself into a particular raid controller that I won't be able to find a few years from now if something ever happens to it.

Danny Bui said:
Will you be re-encoding the videos on the server or on your main PC and then moved back onto the server?
Click to expand...

yes, i don't need to encode it on the htpc itself. I can do that with my other pc that has more horsepower and just transfer the resultant files.
 
Schro said:
I don't think you need to worry about write throughput as long as you're using at least a single drive manufactured sometime in the past decade.

I have personally used several different 7200RPM drives with vintages ranging from 2006-2009 to record 6 shows at the same time - 4 of them HD, 2 of them SD (hardware encoder).

When you do the math on the throughput needed for that, its really not that bad....

<quick math>
4x HD streams @ 10mbit (assuming 720p)
2x SD streams @ 2mbit

44mbit/sec total write needed

8 bits = 1 byte, thus,

44mbit/sec = 5.5MB/sec
</quick math>

From a CPU perspective, the above 6 streams were recorded using an Athlon X2 3800+, which _maybe_ hit a 10% CPU utilization while recording, playing back a show and playing one back over the networkt o an extender. The only thing a faster CPU would do would be to speed up the transcoding, shrinking and commercial processing that is done, but I schedule that for at night when its not being used. This was with 1GB of ram in the system (full specs in my sig)

If you want to be able to utilize cablecard in the future, right now, that future means you'll be running Windoze 7 MCE. Unless the FCC lays down the smackdown with new cablecard rules, this is your only option as I'm quite sure that Cablelabs will never certify MythTV as legit software. Cablecard may require more processing power, as the guys over at Ceton (who are about to release a quad cable card tuner) have a quad core processor as their minimum specs (I presume some of the encryption and DRM tasks are offloaded onto the CPU). The other consideration should you go this way, is that anything you record that is marked as copy restricted, you will only be able to store it on the box that you recorded, and only view it on that machine or media center extenders. Other PC's are a no-go right now for viewing copy protected content (I hope in the future that the Vole allows other Windoze 7 MCE computers int he same homegroup to act as an extender).

Given that, your new setup might look more like a NAS/tuner box with extenders placed around the house.. though.. the only true extender left these days is the Xbox360....
Click to expand...

Thanks. I've read a little about the cablecard issue, but I know I don't need to do that anytime soon either. I'd be ok with just a standard tuner that can read anything a basic TV can read for the near-term. my main issue right now is hard drive space and getting myself a NAS, so I figured while I do that I might as well build it out as if it were my HTPC backend also since I planned to do that at some point anyway.
 
SinShiva said:
also, i did some looking around and found this; http://www.newegg.com/Product/Product.aspx?Item=N82E16813136053&cm_re=ich10r-_-13-136-053-_-Product

ich10r and 8 sata 3gb ports. perhaps something like this might make for a better solution than software raid? it does put you in lga775, though. i can't say i'd be entirely confident in raid 5, but raid 0/1/0+1 should all be quite solid
Click to expand...

berky said:
thanks for the mobo link. i've always been an amd guy and never really bothered looking at intel setups. for the right price and features, i have no issues switching.
Click to expand...

I would not recommend going with Intel at this point in time due to the poor price to performance ratio with Intel 775 CPUs. In addition, Linux software RAID is a tad better than ICH10R raid.

Anyway here's a prelim build so far:
$59 - AMD Athlon II X2 240 CPU
$65 - Asus M4A78LT-M LE AM3 AMD 780L mATX Motherboard
$94 - A-Data AD3U1333B2G9-DRH 2 x 2GB DDR3 1333 RAM
$58 - Western Digital WD6400AAKS 640GB 7200RPM SATA 3.0Gb/s Hard Drive (OS Drive)
$300 - 3 x Samsung EcoGreen F2 HD154UI 1.5TB SATA HDD
$85 - Antec NEO ECO 620C 620W PSU
---
Total: $661 plus tax and shipping

Went a tad overkill on the RAM and PSU but couldn't find a good deal on 2GB DDR3 RAM and a quality PSU. From what you've said so far, 6 SATA ports should be more than enough. It's usually a good idea to keep the OS drive and the RAID array seperate in case something goes wrong with either. The above setup is assuming that you're going to use Linux software RAID 5 via MDADM. That should give you a very nice 3TB RAID 5 array, more than enough storage for what you've described so far.
 
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I would not recommend going with Intel at this point in time due to the poor price to performance ratio with Intel 775 CPUs. In addition, Linux software RAID is a tad better than ICH10R raid.
Click to expand...

i figured that would be true for raid5, but is it for raid0/1?

OP, what raid level do you intend on using?

in the mean time, i'll be looking around for some 0/1 benchies to compare ;p

[edit] having a hard time finding performance information, but i suppose you'll be 'safer' with mdadm if it degrades - i DO agree in that you will more than likely get better raid5 performance via mdadm [/edit]
 
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definitely not 0. i've considered 1, but the costs are a definite factor. most likely i will use raid 5
 
looks pretty good to me. For the PSU, I've read that they are most efficient when operating at 80% or more of their capacity, so I don't want to go too overkill, but give myself enough so peaking the CPU isn't going to overload the PSU. I'll have to calculate out the wattage of all the components. only a few questions remain.

1) how much HDD space will the OS need? I was thinking of using an 8GB CF card for the OS with an IDE to CF adapter. that should keep down the heat and power consumption and since the OS itself shouldn't be writing much, I didn't think I'd have much of an issue there, but if that's not a good idea, let me know.

2) If i go with 3 hdd's up front in raid 5, how can I expand it down the road? meaning, can the software raid expand the array if I add another drive? another 2 drives? 3? etc...

3) what standard encoding do most people use? I've seen .mkv's for high def, but what about standard def? Mostly I've seen .avi files, but with various codecs (Divx, Xvid, mpeg2, mpeg4, etc)

4) what calculation do you normally use for space required for a standard length, standard def movie encoded with the answer to #3? it seems that a 45 min TV show takes up about 350 MB as an avi file. Is that standard?
 
berky said:
looks pretty good to me. For the PSU, I've read that they are most efficient when operating at 80% or more of their capacity, so I don't want to go too overkill, but give myself enough so peaking the CPU isn't going to overload the PSU. I'll have to calculate out the wattage of all the components.
Click to expand...
PSUs are more efficient when operating within 40 ot 60% of their output capability.

berky said:
1) how much HDD space will the OS need? I was thinking of using an 8GB CF card for the OS with an IDE to CF adapter. that should keep down the heat and power consumption and since the OS itself shouldn't be writing much, I didn't think I'd have much of an issue there, but if that's not a good idea, let me know.
Click to expand...
Not too sure. About 4GB minimum ballpark guess. Not a fan of the 8GB CF card for a OS drive for a file server. Seems too limited.

berky said:
2) If i go with 3 hdd's up front in raid 5, how can I expand it down the road? meaning, can the software raid expand the array if I add another drive? another 2 drives? 3? etc...
Click to expand...
With Linux MDADM, yes you can expand the size of the array down the road whether you add one or 6 more drives.
berky said:
3) what standard encoding do most people use? I've seen .mkv's for high def, but what about standard def? Mostly I've seen .avi files, but with various codecs (Divx, Xvid, mpeg2, mpeg4, etc)
Click to expand...
.avi with mpeg2 codec I think.
berky said:
4) what calculation do you normally use for space required for a standard length, standard def movie encoded with the answer to #3? it seems that a 45 min TV show takes up about 350 MB as an avi file. Is that standard?
Click to expand...
[/QUOTE]
Basically (For SD):
45 minute TV Show: 175MB to 360MB
2 hour movie: 720MB to 1.5GB

Generally the larger it is, the better video quality it is.
 
thanks. i think i'm good to go for the immediate term. one last question. if you had to choose a basic tuner, what would you recommend? the HD-5500 seems like a good choice since it was made specifically for linux, but i'm not sure if it's software or hardware encoding. it says software for HD decoding, but I wasn't sure about SD encoding/decoding.
 
I'm not directly familiar with the current tuners that are out there and what works will with Linux, but I can offer this -

HDTV recording tuners will all be software based (whether its QAM or ATSC). All they are doing is tuning to a frequency and dumping a stream straight to the hard drive - the file is actually encoded by the broadcaster.

SDTV recording is where you'll want to have hardware encoding, but I'm not sure if there's a single card out there that is able to do both HDTV and hardware encode SDTV, but I'm likely to be corrected within a few hours of posting this...

All DEcoding will be handled by your graphics card (with the assistance of yoru CPU and some codecs) and not by your tuner card. I think the Hauppauge PVR-350 was the last product out there that had a built in decoder, complete with S-Video/RCA out the back of it.
 
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