The 65Watt Challenge!!!

[nzimmers]

Here's the Challenge

for $600 or less, is it possible to build a home NAS with four SATA HDD's (320GB drives) in Raid 5 (Sata interface) that consumes 65W or less at idle?

what MB and CPU?
which PSU?
which drives?
with a minimum of 256mb or ram

anyone think it's possible?

[qviri]

Is that 65 watts AC or DC?

It should definitely be possible. Four drives should eat around 28 W DC. You probably want to go with AMD since their idle power is much lower than Intel's. The slowest AM2 Sempron coupled with the cheapest motherboard of acceptable quality is probably your best shot. Either go for onboard video or the oldest 4 MB PCI graphics card you can find. PSU efficiency will affect the AC draw very slightly, but if you want to go cheap, a FSP unit around 300 watts will be just fine. A 10% efficiency difference around 65 watts is just 6.5 watts either way, and 10% is a massive difference. A FSP won't be 10% off from a Seasonic.

Which drives? That's up to you . The recommendation de jour around here are Samsungs or Western Digitals.

[Brian]

Ahh, an enjoyable question. I say no way, no how. 65W at the wall translates to about 50W DC. I'm guessing those hard drives draw 10W a piece, which leaves you with just 10W for the rest of the rig. Not gonna happen.

But I'll play anyway.

Buy the cheapest VIA mobo you can find. Make sure it has GBit LAN, integrated video, and a PCI slot. Put a SATA RAID card in the PCI slot. Stick a PicoPSU in it (whose high efficiency means you get more like 57W DC). Add a Yate Loon or Nexus at reduced voltage, et voila. Actually, that sounds like it might just fit under your 65W ceiling.

But you could save a pile of power by going for two 640GB drives (or whatever's available).

[nzimmers]

yes, I was talking about 65W at the wall

are there any 3.5 inch drives that use less than 10W ?

[qviri]

I'm guessing those hard drives draw 10W a piece

The highest idle power draw on the recommended list is 8.5 watt, and the Sammys are 6.3 watt. That leaves 25 or in the worst case 16 watts

[nzimmers]

how about the hitachi T7K500 series? according to storage review, the 500GB version uses 6.8 W at idle....

embedded loooong URL

I happen to have the 320GB version of the drive, I will try to see how much it draws at idle

[nzimmers]

well, according to hitachi's site and storage review,

the T7k500 drives pull an average of 7Watts at Idle

65W (Idle power goa)l
-28W (4 x 320GB Hitachi drives)
=============
37Watts of available power

$600 (cost goal)
-$320 (cost of 4x320GB Hitachi drives)
================
$280

okay, so now there's $280 and 37Watts to play with

can anyone suggest a MB+CPU+Ram combination that uses 37W or less at idle and costs under $280?

[~El~Jefe~]

I will tell you something.... about the lowest power requirement modern motherboard.

it is the via k8t800 pro chipset. It uses BY FAR the least amount of electricity. full speed bus from amd, very light in the wattage, and full use of sata.

now, on that board it would also use raid 0,1,5 settings. what board you get, I duno, I have an abit board for that. Also note that it would use 754 chip. those are normally 130nm but you can get 90nm ones. Still, the 130nm ones sometimes are less powered than the 90nm new ones cuz the new ones are all a64. you can go find (somewhere?) a sempron that is supports cool and quiet or just undervolt it. that would use like 40 watts at idle, the board and that.

also, I would go 2.5 inch drives. pricey, yes, but you could put 4 in an array. they use a lot less power. also, 754 uses single slot dims so you could even gain 4-5 watts of power saved from only having to use one slot.

thats my least wattage solution that would run nicely.

[nzimmers]

great suggestions, I will look for a k8t800 MB

unfortunately, 2.5 drives are way too expensive, if only they would come down closer to HDD prices per GB =(

would a Sempron Palermo core be a good match?

[Brian]

Ah, I was thinking 65W peak at the wall. In which case, HDDs take 9 to 13W each.

If we're talking about 65W typical at the wall, the problem gets a lot easier. Instruct the HDD to spin down when not in use, which should be most of the time (I presume it's a personal-use fileserver, and you're not using it more than a few hours a day). Now they're about 2W each.

Here's one study that finds underclocked, undervolted Semprons draw a miniscule amout of power. Plus, they're really cheap.

[~El~Jefe~]

yeah, i would get though the sempron that has more cache if you could find them.

2800+ sempron... does it exist??? I dont know but! you can look for it.

I am not sure if k8t800 boards have the bios to use a 90nm chip.
It also has 256KB cache on it. I bet it does really well for it 1.6ghz speed. You could undervolt it massively if the board accepts both undervolting and 90nm. That thing would run passive easily with the correct cooler like a scythe ninja.

One could consider looking for a micro atx case with less slots. From what I remember, the less components the SLIGHTLY less wattage is used. 1-2 watts could make or break your goal. I doubt that any boards exist that are like that but might as well search. I would look locally at crappy computer stores for a k8t800 pro chipset.

oh i forgot: it is a K8T800 PRO chipset. the pro means it goes like lightning and has all the sata and other stuff on it.

You wont be using a vid card, right?

----
UPDATE

I dont remember now if there is a difference between k8t800 pro and regular. Hm. Well, you should check that out.

I just saw a palermo core for 31 dollars on Newegg.com.... plus, a biostar board (they make decent boards). Get those, but I would invest in decent ram for compatibility.

I dont know about undervolting abilities of that board or any other board. I know that my abit board doesnt really undervolt. OC's really well but not UV's

[nzimmers]

you are correct, I won't be using a video card

I'd really like to get the total power consumption into the 50's but I don't think that's possible

[merlyn]

what an interesting thread

I'm in the middle of building a htpc/downloader at the moment, mostly from spare parts. it's running at 55W idle atm but then the spec doesn't compare to your wish list and i've only spent £32.50 on it. if i had that hd config it would certainly go much higher and it would no longer be quiet enough. I'm extremely sensitive to 120Hz idle whine of 7200rpm hd's for some inexplicable reason.

I have some questions though. Hardware or software RAID? Is it possible to make an array spin down when idle? It's been a while but I remember some issues with power managing RAID controllers.

I'd go with 500GB drives because the £/GB ratio is better, here at least. My current file server is using 320's and I built it nearly a year ago.

I love the idea of the PicoPSU, just need to find a 200W brick that doesn't have a fan. My HTPC gets to 155W at load not that it ever will irl. Power figures at the wall btw.

[nzimmers]

having drives spin down in a raid 5 array is possible - but it doesn't always work well - if they don't spin up properly the raid has to synchronize again.

not sure if this is a serious problems with newer drives - but my older seagates can put up a fuss.

by the way, what HDD's do you have? I recently found out my older HDD's use about twice as much power as the new drives do.... so that might be an area for you to investigate


oh, if you are looking for 200W fanless power supplies you might find something useful here: http://www.short-circuit.com/categories/pscombos.html

[jessekopelman]

nzimmers if you look closely at the page you linked you'll see that only the DC-DC PSU is rated for 200W -- the biggest AC-DC brick they show is 8.5A = 100W and it is not even fanless! It is very hard to find a fanless brick that is > 80W. They exist, but are hard to find and pricey. All the more reason that your quest for a 65W setup makes sense . . .

[~El~Jefe~]

what about phantom psu's? the are very efficient, do not need fans?

i think spcr tested a 180 watt brick right?

[nzimmers]

How efficient are the AC-DC bricks anyways? I have read posts by others that say 90% or higher but I haven't really seen any specifications that mention that

[jessekopelman]

You can get more details of a specific case, if you read the review of the PicoPSU, but in general: The brick will have an efficiency in the nineties and the DC-DC PSU will have an efficiency in the nineties. The effective efficiency is the product of the two -- something in the eighties. So, AC-DC brick + DC-DC PSU is more efficient than most internal AC-DC PSU, but not more so than the very best (like the fanless ones which tend to have very high efficiency). For <80W applications, it is probably impossible to find an internal AC-DC PSU that can beat a good brick + DC-DC PSU combo. At higher draws, something like a Fortron Zen is probably just as efficient and less expensive (fanless bricks > 80W are so hard to find they must be expensive).

[jessekopelman]

How about this bad boy? Yes $200 is a bit pricey for such a wimpy package, but it only uses 4.1W! Also, because it's an industrial style package you don't need to give much concern to its cooling. To complete the setup you will need to add a PCI SATA controller like this and a boot device. A CF-IDE adapter + say a 256MB card would be a great boot device, but adapters sporting a 44-pin interface are harder to find than 40-pin so I'd go with a 20GB 2.5" drive. For the PSU I'd go with a Fortron Zen (or maybe just some 80+ PSU with a quiet fan, depending on the case), as PicoPSU only has 3 molex outputs. So that only leaves a case and the 3.5" drives. Ideally you'd made your own case to take advantage of the board's tiny footprint. I'd also "cheat" a bit and go with 3 X 500GB drives as this will cost the same and use less power than 4 X 320 GB.

Power Budget
Computer = 4W
SATA Controller = 10W?
2.5" Boot Disk = 1W idle / 3W typ / 5W peak
3 X 3.5" Drive = 30W
Case Fan = 2 W
===================
Total = 51 W peak DC
AC Draw at Wall = 64 W (assumes 80% PSU efficiency)

Budget Budget
Computer = $200
SATA Controller = $25
2.5" Boot Disk = $35
3 X 3.5" Drive = $405
Fortron Zen = $85
Case Materials = $50
====================
Total = $800 + S&H

Ok, so I went way over budget. On the other hand, my Power figures are overly conservative and the real average number is likely to be about 55W at the wall. Over 3 years of 24X7 use at $0.15/kWhr, saving 10W adds up to $40 so we get a little back and that plus the good feeling of using so little juice evens us out

Potential problems I see with this setup are possible slow transfer speeds due to software RAID on a weak machine, but considering the bottleneck of Fast Ethernet this is likely moot. If you are wired for GigE, this would not be the right way to go. More serious issues are lack of graphics and limited choices for OS. I think the available OS choices are good enough for this application. As for the headless nature of the beast, I've dealt with similar and the idea is to have an initial OS load that you trust so that you can get in via a remote terminal and play around.

[MikeHunt79]

anyone think it's possible?

Definitely.

I've got a rig here, and it's pulling less then 50W from the wall with 5 SATA drives and 1 IDE boot drive connected. It can pull up to 60w tho, depending how non-idle it is.

Here's the spec:

Random cheapy 280w PSU I had lying around (modded to fanless)
Epia 5000 motherboard with onboard everything inc CPU (15w)
2 x 128mb of ram (could be reduced to save a few W)
rocketraid 1820 8-port raid controller
1 x seagate barracuda 4 20GB IDE boot drive
5 x 320GB 321kj samsung spinpoint drives.

Gives me around 1.2TB of RAID 5 storage, and is nice and quiet, as drives are suspended. I can post pics if you like.

EDIT: I'm not sure on costs, as I got most of the bits 2nd hand (apart from the spinpoints) - it would definitely work out at less than $800 tho.

[Sylph-DS]

This may not be as much fun, but wouldn't two bigger drives (say, 500 to 750 GB) in a Netgear SC101 work well?

Cons of this are:
- IDE
- no Gigabit lan
- You can't run it properly without the Netgear software on every computer that wants to get into it.
- It just not the same

Pros however:
- Cheap, like €80,- the last time I checked
- Tiny (seriously, toaster sized )
- Pretty easy on the wattage (I don't know any exact number, but there's barely any processing power in there, so it can't be much)

[nzimmers]

This may not be as much fun, but wouldn't two bigger drives (say, 500 to 750 GB) in a Netgear SC101 work well?

it's a nice little unit, I checked some of the reviews on newegg http://www.newegg.com/Product/Product.a ... 6833122073

aparantly the file system is proprietary, not good of the unit dies and you need files from it. Also there seems to be some problems with the Promise drive controller in there, netgear and promise are pointing fingers at eachother

I think the Netgear Sc101 is great in it's niche, but I think having a MB and CPU combo that can accept linux , bsd, or windows has some major advantages to it.

[JohnAStebbins]

In the same vein as Sylph-DS suggestion. Two larger hard drives and a
QNAP TS-101 NAS. Runs linux OS. Supports 1 internal SATA and one external SATA. Spins down drives when idle. Has a gob of nice builtin features and is hackable.

No raid 5, but from what I've read recently, the presumed safety net you get from running raid 5 isn't as safe as you might think.

http://www.newegg.com/Product/Product.a ... 6822107001

[NeilBlanchard]

Hello,

There are other NAS units that might meet the challenge:

http://www.newegg.com/Product/Product.a ... 6822165026
47watts peak

[jessekopelman]

Neil, that's not a NAS -- just an external drive.

nzimmers, I think at this point you can conclude that 65W idle for $600 is probably achievable, but that <= 65W peak takes a more expensive system. Certainly the lower power system is not going to pay for itself in energy savings, but it might in cool factor.

[jessekopelman]

I think a lot of people posting here don't understand some fundamental RAID concepts and why nzimmers would want RAID 5. Here is a very basic primer:

RAID 0 -- aka striping, basically you have turned 2 physical drives into one logical drive whose size is the combination of the two. There are some potential speed benefits, especially on reads, but you have actually reduced your data safety as if either physical drive fails the entire logical drive is ruined.

RAID 1 -- aka mirroring, basically you have turned 2 physical drives into one logical drive whose size is the smaller of the two. There is a uniform speed penalty on writes and a potential speed benefit on reads. Your data is much safer, as either physical drive can fail without effecting the other. The big problem is that your cost per MB has doubled, since you need two drives to do the storage job of one.

RAID 5 -- Similar to mirroring, but data is spread around so that logical drive size = smallest physical drive X [number of drives - 1]. You need at least 3 drives to do this configuration. Unlike RAID 0 and 1, RAID 5 requires a lot of computation to spread the data properly throughout the array. This means that you either need a dedicated controller or you will see CPU utilization impacted. However, with a small array size and limited number of simultaneous users, any current production CPU should be more than adequate to provide Fast Ethernet (100 Mbps) speeds. The big advantage of RAID 5 over RAID 1 is a much lower cost per MB as the array size grows.

[nzimmers]

Right, my point exactly is that Raid 5 offers a level of redundancy at a lower cost per GB than other mirroring options

the BUFFALO HD-W1.0TIU2/R1 1TB is very very nice, but the only redundancy it can offer is mirroring, so to get a full TB of redundant storage you need to buy two of them (2x$469=$938....ouch)


I recently noticed something on ebay, the mobile celerons (socket M variety) can be bought for about $20 shipped, which is kind of a interesting option

[matt_garman]

Gives me around 1.2TB of RAID 5 storage, and is nice and quiet, as drives are suspended. I can post pics if you like.

I'd be interested in seeing pics

[matt_garman]

You've already got lots of good suggestions, but take a look at the motherboards available at Logic Supply. As one example, this motherboard, equipped with a SATA PCI controller card, would probably meet your power requirements.

Also, if this machine will just be a file server (i.e. not running any other processes), you can have a fairly wimpy processor and still not have software RAID be a bottleneck. At least Linux software RAID. IIRC, all that's involved in RAID (level 5 at least) is computing parity and addressing. Your system's I/O bandwidth will typically be much lower than your (wimpy. low power) CPU's parity+addressing computational bandwidth. (Don't just take my word for it though---I haven't researched this in a while... and I don't trust my memory too well!)

Since it's been mentioned, what are you performance requirements? What OS do you expect to run?

I'll go ahead and plug Linux software RAID, like I did in this thread. I think it's a great, low-cost solution.

Matt

[jessekopelman]

You've already got lots of good suggestions, but take a look at the motherboards available at Logic Supply. As one example, this motherboard, equipped with a SATA PCI controller card, would probably meet your power requirements.

That board will bust the budget. My try with a $200 board ended up at $800 and that board even included RAM! Four 320GB drives will set you back over $300, leaving just $300 for MB + CPU + RAM + any needed PCI Cards + Boot Device + PSU + Case. 65W ain't hard, but 65W for $600 is.

Also, if this machine will just be a file server (i.e. not running any other processes), you can have a fairly wimpy processor and still not have software RAID be a bottleneck. At least Linux software RAID. IIRC, all that's involved in RAID (level 5 at least) is computing parity and addressing. Your system's I/O bandwidth will typically be much lower than your (wimpy. low power) CPU's parity+addressing computational bandwidth. (Don't just take my word for it though---I haven't researched this in a while... and I don't trust my memory too well!)

I read some Linux software RAID testing results done way back when with a a dual 133MHz P2 setup with 128MB of RAM. Dual 133MHz P2 has got to be weaker than any solution you could buy today and it would be hard to buy less than 128MB of RAM. Anyway, the tester got 10+MBps for both reads and writes at RAID 5. Given that the idea is to build a home NAS and the bottleneck from Fast Ethernet is right around 10 MBps, I think Linux software RAID is good to go unless the home in question is wired for GigE.