Need Advice... On Nas Devices

[welo]

siamect,

thanks for joining the discussion and taking the time to read my long post

I actually did more reading after my last post and found an interesting article that deals with the aspect of 'power efficiency per task' which you are talking about. tomshardware compared the low power Atom CPU to one of the more efficient dual core CPUs back then, the Intel Core 2 Duo E7200 (the article is from Dec 2008).

The E7200 was (and is) not a high performance CPU and therefore rather efficient. Intel brought down the system idle power of the E7200 to nearly the level of the Atom system - this is rather impressive! Consumption under load is - of course - still a lot higher than the low-power Atom platform, but surprisingly low for a desktop CPU. This is due to the combination of the rather energy efficient E7200 with the also rather efficient Intel G31 based motherboard.

But here comes the real surprise - or not, since this is exactly what you were writing about - when it comes to absolute power consumption in Watt-Hours for specific task (here: running a specific benchmark), the E7200 wins. This is easily explained by its much better performance, it just takes shorter time to complete the task and return to idle.

So the Intel Core 2 Duo E7200 is actually the more energy efficient CPU (system) in this case!!!

Some thougts/notes:

• This does surely not apply to all Core 2 Duo models, especially not to the models first released on the market and to the high performance models
  
• A lot depends on the rest of the system components (if no addon cards are used: the motherboard), and a less efficient motherboard can turn the result upside down - the G31 is actually a low-end / low-budget chipset and perfect for this setup
  
• We still didn't look at the costs - Intel Atom Combos (motherboard with onboard Intel Atom CPUs) are pretty low cost and hard to match/beat.
  

Netbooks need to be awake all the time because it is a desktop environment waiting for a person to do some input . But no one expect a Netbook to be a high performance animal. Response time is more important than overall performance. There you gain a lot by having a low power low frequency processor that is always running when somebody is typing. A NAS that is mainly used for backups does not have to be quick in response and you can put it asleep and spin down the disks. But it does need to be fast once given a task.

Not sure this comparison makes sense to me. Modern CPUs constantly switch between idle and power state (and the states in between), and change seemlessly between frequencies. Maybe you talk about other system components, not sure how this applies there.

I guess a simple NAS is maybe even more suited for a low power (and less powerful) CPU than any desktop environment, since there are no CPU intensive tasks to accomplish. The CPU is no bottleneck, there is no trade-off in using a low power CPU. For NAS boxes the Atom is actually a more powerful choice than the often used Marvell CPUs AFAIK which have become a bottleneck since the software running the NAS has become more complex (FTP, torrent, CIFS, etc).

The next question is: What is the idle/sleep consumption... and how much of the time is spent on idle. Can your hardware support sleep mode and wake on LAN...

Are your clients happy to wait for wake on LAN delays? If you have a low power CPU but it need to go on full speed all the time maybe it consumes more that a fast cpu that can sleep 90% of the time...

Based on this... throw away old hardware...

And i think you can build a very "green" server from scratch if you look around for the right components.

I agree on this one. I think, however, that this applies to REALLY old hardware (Pentium 4 and older?) and/or quality and choice of components (mainly the motherboard and its firmware). Desktop systems have been improving over the years when it comes to power management and WOL, but you still need a bit of luck to pick a system or components that will work as reliable as for instance laptops.

Installation... [and software]

I've never built or administratored a small-scale NAS (which this thread is about) so I can't really comment on the software part. People here mentioned freeNAS which is a special Linux distro that aims to provide similar features for your self-made NAS box that commercial off-the-shelf NAS devices offer. Don't know if freeNAS can really keep up.

One post on another website got me thinking. That person said that special NAS software gets you started lightning-fast compared to a standard Linux distro, but if you miss any feature and try to make this work on a NAS box, you will easily spend more hours than you might have saved before.

[robblok]

Welo,

Just for your information i have owned a buffalo linkstation quad (that i am in the process of selling) and a QNAP 459 pro turbo.

I must say that the software of the QNAP is much better and faster and has much more options (and you pay of it of course). I have looked at FREENAS and it looks a lot less then the software already on the QNAP.

You can even add stuff to the QNAP (i haven't tried this yet) because it does all that i want.

So there is certainly a difference between different NAS devices what they come with standard.

http://wiki.qnap.com/wiki/XDove_Configuration (for the QNAP)

Edited May 15, 2010 by robblok

[welo]

Yeah, I know that free software projects often lack quality in the details (ease of setup, user interface in general, etc), that's why I am careful to promote/recommend/give_any_opinion_about freeNAS. A comparison of the feature table will not bring any results either, since Linux based distros can probably offer anything you want, but not necessarily at the convenience level you'd expect.

That said, the quality of open source projects CAN be very high (mostly if one or more companies are backing it ).

Interestingly after doing some reading it seems that QNAP actually started promoting open source projects on their platform to provide additional functionality by introducing their QPKG package manager and encouraging the build of open source based packages.

I guess this is a good approach, focus on the core NAS services and provide additional features through 3rd party projects.

But it is not necessarily off-the-shelf-box vs. self-made/open source, you can also opt for self-made/commercial with openfiler or NASlite. openfiler is available under open source license as well.

welo