WD Green or Red drives

Red.

WD has designed for NAS, lolok to the HP from WD.

RED! No Doubt.

RED !!!!    Green is old tech

Red is designed specifically for home and small office NAS systems and PCs with RAID & are ideal for streaming.  They are quieter than other WD drives as they run slower when running light (i.e. streaming music)

Red is the current WD recommendation for NAS. They are tested to run 24 x 7.

Green is not old tech but now only recommended where low power is the primary concern, they will idle down too soon in a NAS, and then take longer to spin up and this does confuse streaming software into thinking access has failed.

Any modern hard drive is capable of streaming high res music, it's not vey demanding. However, most non-server drives are not capable of handling lots of concurrent different users very well. So if you have a busy family all wanting to stream different things then life gets harder.

IMO the best solution to the above is avoid single drive NAS devices and use mirrored pairs. Most NAS dvices use a Linux kernel which knows that data exists in two places and will use that fact for multiple reads. This won't happen on RAID-5/6. So, a 4 bay NAS run in two mirrored pairs with your data spread between the pairs will give best results.

What I meant by old tech is the Green HDD have been around a while before the current Red was introduced 

Ian_S comment about RAID is a bit incorrect I'm afraid.

A 2-disk raid mirror MAY read from both, rather depends on the access implementation/controller but obviously makes sense to read from both as the data are on two disks, though I doubt it will exercise the disk any. My el cheapo and old single disk video recorder can record two shows and playback another one simultaneously: not very demanding as Ian says.

Raid 5/6 MUST read from all your disk as the data are spread across them. Access to parity for reconstruction will slow it down a bit I guess, if theres failure but these days the devices are so performant for music one may not notice.

Theres plenty info on RAID levels on the interweb. RAID 10 is the preferred route for many a valuable data/availability situation, but we are talking minimum of 4 disks which may be better deployed with a mirror of two that are also mirrored to another pair elsewhere.

popi

Thanks all.  You comments and advice is much appreciated. Red it is...

2.5" drives will be quieter than 3.5" drives and should consume less power as well.

You might be right David,  but the 3.5" are in no way noisy. My Synology has 3.5" WD Red's & the only time I hear anything is during power up/down sequences - (only done when I'm away from home) It lives in a closed door cabinet in the listening room & is effectively silent. 

Likewise, I have a Synology NAS with WD Reds and its both quiet and cool running. Always use drives on the compatibility list.

FWIW I have a QNAP TS-112P + WD Red, sited on an open shelf with other A/V equipment. I have been told, and read, many stories about noisey NAS but it is very quiet in operation. You can hear the drive starting-up but in no way is it intrusive or annoying.

Dave

When I bought my HS-251 I had a spare WD Green, so I bought just 1 WD red and I use the red one to stream and the green one to backup the red HDD once a day. Everything is working fine, quiet and reasonably cool.

But if you have to buy 2 new drives than stick to Qnap recommendations!

Red.

Warranty is longer isn't it?

I've recently installed a new NAS, and I went for the TS-451, which is the four-bay version of the one you're considering. With four 3TB WD Reds it runs all but silently, only making a very little drive noise when doing non-streaming things, and even then it's not audible unless you really listen for it. It also runs cool and fast, but then I have upgraded the RAM to 4GB from the standard 1GB.

Mine runs without RAID as JBOD (just a bunch of discs), but then it's backed up by another older QNAP running four more 3TB Reds. I also have a third NAS (a two-bay QNAP), used for general computer backups – the main two just run music – which is running two more 3TB Reds.

The two units both run Twonky, Minimserver and Asset, mainly for testing purposes: if I had to choose one, I'd probably go for Minimserver, which used to be a faff to install, but is now part of QNAP's QTS Apps offering, so installing it takes only a couple of clicks in the web-based control system (which incidentally is hugely improved from what was offered when I first started using QNAPs).

Have only ever had one glitch in all the time I have been using the Red drives, and that was solved using WD's disk utilities, which is a free download.

Hope some of this helps a bit.

I agree with all that has been said. However I would suggest to add a single drive backup. My setup is a QNap dual drive NAS with two WD Red drives running in a mirror pair. Attached to this is an esata single drive with another WD Red in it which contains a backup. My experience is that actual NAS enclosure electronics may fail before the drives, especially in the dry air we have in Alberta. I've never yet managed to get a pair of mirrored drives to work in another NAS box of even the same make. But the external drive will give you the chance to copy back all of your files to a new NAS box.

Tim

+1 Red They work very well in my Sinology 213J

Guys, thank you all very much for your help and guidance. It's very much appreciated. I have a lot to take on board but one thing is for sure, it will involve WDRed discs!

However, i am tending to using JBOD in the NAS unless you can convince me that there really is a sonic improvement in some kind of RAID arrangement. I don't believe I need RAID for backup as with fibre broadband and could backup I'm pretty well covered. But I am open to persuasion...

Thanks again. DTB

If you have a back up of your library, RAID is unnecessary. I do have my music collection in a RAID array plus two (one off premises) back ups. My streamed videos reside on a faster NAS and much larger discs. My video files are also comprehensively backed up but because they take up so much disc space (and are properly backed up) I store them on two JBOD arrays. It would take days to recover from a disc failure, but a complete recovery is just as possible as replacing one disc in a RAID pair.

As for sound quality, I can't tell a difference between disc types (used to date) or NAS types (used to date). Everything sounds the same to me. I've never bothered to compare RAID with JBOD. You can never be 100% certain and different people might hear different things. For my own part I am confident about what I would most likely hear. Which is no difference.

Please use RED. I have used Green and they fail prematurely under the NAS environment.

In case of an crash "warranty doesn't" matter if your datas are gone.

A NAS, with what ever type of raif or parity disk or what in hell is not a BACKUP.

BACKUPs are highly recommended!

Ragmans comment is full of value.

You don't want to have to rip or download things more than once...RAID mirror could corrupt both/all copies, so advocating a backup as ragman and other have is good sense indeed.

You could even try a restore of your backup ( at regular intervals) , so as not to encounter surprises should you have to rely on it.

I thought we had all pretty much covered that already?

It's no more incorrect than what you've said on RAID5/6... imo

Yes in RAID 5/6 a large file will be spread over all disks, but each chunk of that file will only be stored on ONE disk. So to stream a large file, you retrive each chunk in sequence from the one disk it will reside on (ignoring parity which is only used in a failure scenario) and then the next and so on. Now, *if* the controller/software is intelligent enough to recognise sequential reads then it might pre-fetch chunks to cache in parallel, but once multiple requests are made of it, life is harder as you can't read the chunks sequentially *and* in parallel... so that I/O pattern becomes more random which is the one thing consumer drives don't do very well.

In a RAID1 scenario, one disk can simply stream one file sequentially, and the second disk another without having to intereave the requests between them as each individual disk has a whole copy of the file.

And yes, PVR's can do dual streams, but it only works smoothly with drives that have firmware that is tailored to that task. If you remember the bad old days of SkyHD boxes with small HD's and home replacements, you stood more chance of finding a disk that worked badly inside one than you did adding one that worked well... this is why the likes of WD came out with 'AV' drives to support that usage pattern just like we now have NAS drives..

Sorry if this is a little off topic, but this and Wifi are two main reasons why streaming is often hit and miss at home, and gets more so as the resolution of files increases. I don't know about others here, but it's becoming increasingly rare to have just one device using a home network at a time any more, so IMO these things do start to matter.

Just to re-iterate:

REDs are designed for NAS use.

Greens are designed for low power desktop use.

The NAS environment is too stressful for GREENs (not the access, just the 24x7 powered up condition).

REDs are much more reliable in NAS environments.

Reds actually get quieter again a few minutes after they power up, as they slow their platters down when in low demand rate conditions (such as audio streaming).

Note: RED Pros don't do this as they're designed for high demand enterprise level usage.