Interesting Noise Damping Discoveries

evildave

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http://www.7volts.com/

This is a very interesting site, full of very good information.

http://www.gideontech.com/guides/xtrahd/
Came up because it was linked by the other site to a handy fan controller project, but has some additional interesting tidbits.


I've been pricing assembling a video (Freevo) server in a Yeong Yang YY-0221 chassis, that could comfortably house 16 hard drives (for 4TB of storage, given 250GB drives).

Even more drives than that with some judicious modding.

One of my concerns was that it would be noisy (especially when it had several drives in it, and the extra cooling and power), so I began looking into noise dampening techniques. The 7Volts site just went on and on and on about it.
 
If you're serious about noise reduction, you probably want to consider water cooling. It takes a bit of cash, and probably the same amount of work as all the noise-reduction you can do with fans, but it will be significantly quieter.
 
The site mentions the water cooled solution, and some sites even mention the water cooled solution in conjunction with this (YY-0221) chassis. I think I'll keep water out of my computer.

I gave the water cooling a bit of consideration, but it seems to me a big, fat copper heat sink with a large fan blowing on it would do all of that (at least for the CPU fan). The more things that need to be cooled by water, the more hoses, and the more hoses, the more the possibility of LEAKS sort of *grabs my attention*. That's all I need. Assemble three terabytes of hard drive storage, get all the configuration and stuff sorted out, and have a hose piss all over its guts, get water into the power supply, and make a nice soaking, smoking mess out of all that labor and money.

No thanks. Besides, the water solution does nothing about whirring and clickety-clickety drive noise from up to a dozen 250GB hard drives running at once. I bet the pump in the water cooler is audible, too. Especially if placed in a hollow steel box on my hardwood floor.

A nice, dry solution to my problem might serve me better. The information about isolating vibration from hard drives and (dry) fans is straight forward. As is the airflow information. The high density carpet pad on the big flat places sounds promising, as does isolating hard drive vibrations from the chassis, and moving and ducting fans around to where they'll do more good.

I actually have a computer based on the Antec Sonata case that's already quieter than my TFT monitor, but the Sonata doesn't have the internal real estate for the storage requirements I have, and won't (by necessity) be right next to me, where the projector and audio/video components are. The YY-0221 does have it, and will allow ONE solution for noise to cover it all. If I can make the cube silent, I have the whole war won, as opposed to just a single battle.
 
evildave wrote:
I've been pricing assembling a video (Freevo) server in a Yeong Yang YY-0221 chassis, that could comfortably house 16 hard drives (for 4TB of storage, given 250GB drives).
Click to expand...
Hey, Dave, you gonna run Windows on that rig?
Exit-Stage-Right.gif
 
Probably Linux - that's what Freevo runs under. It's a minor complicating factor with hardware selection. Making sure there are already drivers for things.
 
evildave said:
The more things that need to be cooled by water, the more hoses, and the more hoses, the more the possibility of LEAKS sort of *grabs my attention*. That's all I need. Assemble three terabytes of hard drive storage, get all the configuration and stuff sorted out, and have a hose piss all over its guts, get water into the power supply, and make a nice soaking, smoking mess out of all that labor and money.
Click to expand...

Good point. That's why most places will strongly recommend using distilled (or at least "de-ionized") water, because pure water is not a conductor.

Which distro are you going to use? :)
Mandrake is really great for auto-configuration of all your hardware, but I'd go with Gentoo for any non-desktop purpose. I know, I know, everyone loves Debian these days, but I've always hated its installer; what the hell were they thinking when they came up with dselect? I get a warm fuzzy feeling with Gentoo, knowing that everything is being compiled for my processor ("-march=pentium4") :)
 
Once the distilled or de-ionized water mixes with the dust that will have inevitably collected on the components, it will become "impure" and conductive. Dust is mostly bits of human skin (plus any of your pets' dander, and other things), which carries plenty of salts and other mineral content to make the purified water conductive. No matter how "good" you are about keeping your computer clean, short of totally dismantling it every week, there are places the dust will collect, that the water can get to before it goes somewhere carrying a big, fat difference in potential (i.e. the innards of one of those switching power supplies - I'll probably have two of them in there before I'm done, and one of them is a couple of years' "proven" (used)).

Condensation is also a big issue! The hose doesn't have to leak to drip water. Someone leaves a door or window open on a humid day after the A/C has been going (or just in the morning) and the computer's going to be sopping wet inside. Finally, the resevoir needs occasional refills, as some of the water will evaporate, and these refills can also lead to "spills". Finally, all of this equipment, including the radiator, tends to be bulky, and will consume space in my box that could have used to house (you guessed it) more hard drives.

I'm pretty sure Freevo needs at least an XWindows server, and other miscellaneous desktop services. Besides, I might want to browse the web, edit & compile my own mods to Freevo, or do other little things with the big, fat box. Probably using VNC, which also needs X.

I am still thinking about using 1394 for the hard drive interface. It makes them all "hot swap", and at about $45~$50 per pair of drives adapted, it's not too expensive. Especially given what an IDE "hot swap" gadget normally costs. It also allows the eventual capacity to reach 15.75 TB (assuming I keep using 250GB HDDs long after the price of 320GB, 400GB, even 500GB hdds flattens out). There's always a clear path to more space, as opposed to IDE controllers, that tend to support a low number of devices. It also lets the drives be further away along the cable.

Another little technical issue is whether I can instruct hard drives to "sleep" when not being accessed. Ideally when playing a movie, or recording a show, it should be using one or two drives. The other dozen or so should stay in an unmounted spun-down mode. No spindle action. No seek. More or less "off", waiting for the system to mount it. This would make the box consume a LOT less power, and make it a lot more quiet.
 
evildave - do you have to have the hard disc array in your living area? Don't you have a cupboard in another room or something? A friend of mine has a smaller array (4 drives) that he keeps in a kitchen cupboard to avoid the noise issues.
 
I can't offer any advice, but I CAN say "Holy crap."

My computer has 20 gigs. Total. TERABYTES?!?!?!?!
 
Right at the moment, there aren't any clear non-interlaced wireless solutions to carry the VGA signal to the projector, so it will need to be near it until the wireless networking to video and audio is better defined. Like if I were to do an XBOX hack to make it a video client *AND* get that to always output non-interlaced signals....

I'll probably put the box right under the amplifier, right under the projector. The little tower's heavy and on coasters....

Eventually, yes, it would be better off in a closet or something.


As for terabytes being a "lot" (I remember when I paid for a 20MB HDD, and thought that was a "lot"), consider the idea of 'ripping' DVDs to play them like MP3 files.

If you're familiar with MP3 files, they're just a more compact representation of what's on a CD. In the case of serving the video, we're looking for a more compact place to put DVD data. Of course, the DVD data is already compressed, so there isn't a lot to be gained in 1's and 0's from re-compressing it.

A DVD can contain 4.5GB if it's a single layer disc. Dual layer, it's 9GB. If your movie hiccups about halfway to 2/3 of the way through, it's generally dual layer. Dual sided usually means one side is "letter-boxed" and the other is "pan&scan". 26~55 DVD discs is one 250GB hard disk drive (and no more hiccups). Now take 26~55 DVDs in their cases and stack them up next to a hard disk.

I have 329 DVD titles. Some of these titles represent collections of DVDs, in that they are TV seasons of shows, or other multiple disc sets. So round it up to 400 discs, off hand. If they were all single layer, that would be 1.8TB, but many of the movies are at least dual layer. Some with "extra features" on a second disc. All of them requiring handling to be played, and prone to get 'misplaced'.

Suddenly those terabytes start adding up.

Then there's the problem of accumulating TV episodes off the air. Why should I limit myself to 100 hours? 200 hours? 1000 hours? No reason. Just keep adding storage. Too much effort to delete old stuff, anyway.


Another option presented its self today for the configuration.

SATA RAID

A RAIDCore RC4852 controller costs $317.00, supports eight SATA drives and four of these cards can be resident on the same computer. It has many flexible high-end RAID features. The cost is on a par of "upgrading" the original 1394 ('Firewire') based design to 1394b ('Firewire-800').

The Highpoint RocketRAID 1820 is almost half the price at $165 and also supports eight drives, but I haven't received any answer to my query about a multiple card installation. (Can I reasonably expect to get two or more of these cards into one box?) At this price, the SATA and 1394 hardware prices are a wash for up to 32 drives. That's twice as many as I'm likely to install. Less mess inside, too. It even comes with SATA cables. I don't necissarily need it to "stay up" and be available in the event of drive failure, and am content to let it "thrash" for a day rebuilding a drive, if it discovers a bad one.

However the RAIDCore might be a good enough susbsystem for the price of one extra disk drive that it could probably be trusted with a seven drive RAID-5 configuration (six drives of data, one of parity, one drive's worth of hot spare), and it supports a "distributed" spare, meaning it can recover from a RAID... TO A RAID. This could mean I might trust it to keep the video data "backup" on RAID***. In addition, it can configure different kinds of RAID onto the same disks, including using the "extra" space on larger new drives that are added to an existing array. (i.e. You have a 5 disk RAID-5 based on 250GB drives, you add three more 320GB drives, and the extra 210GB of data can be turned into another 140GB RAID-5 array. Too cool! You can disband a RAID 0+1 to a RAID 0 + cold (hidden) spare. All while it's still running!) The eight drives can be *any* combination of RAID configurations. Like a two drive RAID-0 array for cache/swap operations, and a six drive RAID-5 for data you care about.


*** RAID is no substitution for a backup... Real work ALWAYS must be seperately backed up in an off-line fashion. That being said something that's only time consuming and mindless, like feeding DVDs back through one or two DVD ROM drives over the course of a few days wouldn't kill me compared to the cost of a set of real, live redundant backup hard disks. As long as there's a redundant checksum AND a hot spare, I believe the chances of a catastrophic "two drives dead today at the same time" failure is relatively small, though with eight drives (or more - it can build a 32 disk RAID-0 array with 1GB/sec throughput, if you're out of your mind) the chance that any given drive might fail shoots up quite a bit.
 
On the minus side, RAIDCore seems to be "still working on" their Linux drivers, and projects them to be completed Q2 '04. Hopefully they're not on the Halo-2/Halflife-2 release schedule for that.
 
I was just given this old 486 based Voice Mail server by a guy in the building where I work because I admired the case so much. It is about 3 feet high with 8 drive bays (4 were filled with 1 gig Quantum fireballs) and looks like something out of Collossus: the Forbin project. With a little Dremel work I am pretty sure I can fit a ATX form factor board in it and use It as the media server for my house.

I was planning to run a cheap Celeron board with 2 Highpoint 4 SATA controlers in RAID 0+1 (I have matched pairs of drives).

Do you think that will be fast enough to stream video over a wireless network?

Presently it would be going to the S-video out of a old ATI 8500 into a TV, but I plan on going Plasma in a year or 2 and wonder how much bandwith I will need to stream recorded HDTV/Uncompressed DVD's on a home network?

Suggestions?
 
evildave said:
Right at the moment, there aren't any clear non-interlaced wireless solutions to carry the VGA signal to the projector, so it will need to be near it until the wireless networking to video and audio is better defined. Like if I were to do an XBOX hack to make it a video client *AND* get that to always output non-interlaced signals....
...snip...
Click to expand...

You could keep the PC in the living area and just have the hard discs array elsewhere. That way you can get the best of both worlds. Building a "silent PC" without drives isn't too difficult as long as you don't want overclocked dual P4s with a latest "we need another slot for a third fan because we can't design cool running boards because we are rushing these beauties out quicker then you can say pixel shader" graphics card.
 
Mine is probably going to be initially based on a recycled 1.2GHz mobo, actually. For video, the CPU doesn't have to be much of a screamer; the bulk of the work is done in the video card nowadays. For a server, even less so.

As for the home network, I'm not quite certain, because that depends on a few variables. First off, you will NOT get uncompressed video to stream over the network, except perhaps with gigabit LAN. And you would need a computer on the other end, anyway. If it's already (or STILL) compressed data to be sent to something to play it back, it should be able to play smoothly at a few megabytes a second.... assuming nothing else grabs big hunks of the bandwidth. A cheap, wired 10/100base connection should do fine, assuming it's switched from the rest of the network so anyone else's *peak* demands don't mess with it. You could actually play two different things off the same network card. You just need something to pick the stream off and decompress it and display it. A little computer of some sort near the monitor/amp. Not much. The nice thing about modern VGA cards is it's already "HDTV", already non-interlaced. It's simply a matter of playing it back in "full screen" mode, which most support. Then getting some sort of remote control to work.

This is my problem: I don't have any convenient spots to bring a wire out of, and a wireless 802.11b hub MIGHT have the bandwidth to do the job for one stream, but it probably wouldn't have quite the bandwidth to recover from errors or a little interference, and that interference is quite likely, since that range of frequencies wireless hubs use (and most wireless video devices use for that matter) is 'fair game' for everyone else's wireless phones, toys and doohickies.

An AT->ATX case mod should be a fun whole entire weekend or so. I hope you have an ATX chassis ready to canibalize. You'll need it.

PLASMA TV??? Seriously, look into DLP (front) projectors. For a fraction of the price of that big, fragile, immovable PLASMA screen, you get an ENORMOUS image, and you can just pick it up and carry it off when you want to see big pictures somewhere else. Mine's an Infocus X1 projector I got for $900 with "only" 800x600 resolution, and it's just plain awesome to watch movies on. 2000:1 contrast. Really dark to really bright.

Sure, you need to be able to dim the light in the room a bit for best results, but even on a white texturized wall (i.e. NOT very flat, NOT a dedicated screen) it looks great.

What would you get for $900 in plasma? Nothing. $6000 for a 60" screen? I get a flawless 120" screen anywhere I want one. If it's darker the picture can get MUCH BIGGER.
 
Thanks for telling me about the projectors, I didn't know that they had gotten so cheap.

I have the Plasma thing on my mind because there is a company in my building that sells/leases them to corporate situations and they let them go at a good price.

I have enough spare parts to build the media center box near the tv, I was going to go with a Shuttle SFF cube with a Celeron and a Radion 8500, the motherboards have a 10/100 NIC and pretty good AC3 sound. I guessed that that might be enough just to play the video.

What I might do is just put a 40Gig in that, and transfer things over as I need them so I don't have to worry about the stream.

What about Bluetooth? how fast is that?
 
Even more important than the cheapness on the DLP, it looks fantastic.

Bluetooth is about 1Mb/s. 1/11th the cheap 802.11b. Darn, I got 802.11b/802.11a backwards in the previous post. Anyway, way too slow. Unless you want to stream low res MPEG-1 with lots of artifacts.

As for pre-caching, not a good idea. You probably don't want to wait 90 minutes to play a 2 hour movie. If you can move the data a little faster than you can play it, it can be streamed real-time.
 
Water cooling won't help you with noise from a dozen 7200RPM HDDs. If this is just going to be primarily a video storage system, you don't need a particularly fast CPU, so you could get by with a large, low RPM CPU fan. Presumably, this chassis you're looking at has room for larger, lower-RPM chassis fans.
The HDDs are where the noise is at. My case is loud enough with 3 7200RPM drives. Try 5400RPM drives if speed isn't a critical issue. You should also try using isolated drive mountings--rubber standoffs reduce vibration and help with noise.
Also, you can use sound absorbtion matting to surround your drive bays and chassis with (but keep in mind you still need airflow).

Low-RPM fans, the matting, and 5400RPM HDDs would go a long way to making a quiet fileserver.
 
Pretty much exactly what the site recommended, except that they said the high-density carpet padding adhered with rubber contact cement was better than the ($$$) sound absorbent stuff.
 
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