Seagate 1.5TB versus WD Green 1.5TB - Sort of a Poll

[spinbot]

I've read various reviews on each drive.  I've read various posts about users running either type successfully.  I've read good things about each.  I've read bad things about each.  The more I read, the more I conclude I have no idea which is better to get for UnRaid use.

 

I see a general consensus that the 7200RPM Seagate is a better (albeit slightly) option for the parity drive.

 

If you were going out today and had to purchase your first 3 drives for your UnRaid server, what would you get if these were your only two options and they were the same price?  Would the WD being $20 cheaper change your decision?

[WeeboTech]

At the current time you will see me advocate the Seagate 7200 RPM 1.5tb 32MB cache. (even it it's $20 more).

If there were a 7200RPM 2.0TB drive, I would suggest that for parity.

 

After parity choice, the rest depends on your usage. 

For movies. any of the green/L{ 1TB / 1.5TB drives are file.

[spinbot]

I'm just about to make my purchase of my server hardware and I started to doubt my Seagate selection as one of my current PC drives ( a 1TB Seagate ) started making some ticking noises and was no longer accessible.  I shut my PC down and used my laptop for an hour, return to the PC , rebooted and its fine now.  I just downloaded "SeaTools" to see if it can determine if anything is wrong with it.  I also shifted a bunch of data off of it , just in case.

 

One of the forum posts I read said that the UnRaid system will be as fast as the slowest of the drives ( data or parity ) as each operation has to read from both and write to both.  So, if you run Seagate's 7200 for parity and WD 5400 for data, the WD would supposedly slow things down a little?

 

I would get the 2TB drive, if the price was better ( and in time, like all computer components, it will drop ).

 

Pricing (in Canadian) for the 1.5 drives right now is $110.88 for the WD and $128.88 for the Seagate.    The $20 difference isn't really that important, selecting the best drives is

[Joe L.]

One of the forum posts I read said that the UnRaid system will be as fast as the slowest of the drives ( data or parity ) as each operation has to read from both and write to both.   So, if you run Seagate's 7200 for parity and WD 5400 for data, the WD would supposedly slow things down a little?

That is only true when writing to the array. 

 

When reading, only the data drive is involved, and since unRAID only does 1 I/O operation to one data disk, and not 4 to two disks, the disk rotation speed is far less significant.  (The 7200 RPM drive might still be faster to get to the initial sector being read, but even a 5400 RPM disk will be faster than your network) 

 

Joe L.

[spinbot]

When you say "faster than your network", are you referring to the ethernet connection speed as I will have a gigabit network or something else like bus speed as being the slowest part of the process?

[Joe L.]

When you say "faster than your network", are you referring to the ethernet connection speed as I will have a gigabit network or something else like bus speed as being the slowest part of the process?

Yes, I'm referring to your gigabit network.

 

When reading from a single disk over the LAN, the biggest bottleneck will be your Ethernet connection, regardless of the speed of your physical disk. 

I've read somewhere that the real world performance of a Gigabit lan will be somewhere between 300Mb/s and 400Mb/s,  or between 3 and 4 times the speed of a 100Mb/s LAN.

 

400MB/s divided by 8bits = 50MB/s...  best case...  Most modern hard disks can do better than that.  An old PCI Bus can do 133 MB/s.  An SATA-1 drive can do 150MB/s.  (limited just slightly if on a PCI bus and only reading one disk)  SATA-2 is 300 MB/s.  All are faster than the LAN.

 

Joe L.

 

 

 

[spinbot]

Thanks for numbers.  It definitely helps with understanding things.

 

The bargain hunter in me says go "WD Green", but the loyal part of me says go "Seagate" as I already run 4 Seagates now.

 

Might be decided by the ancient technique of "eeny meeny miny mo" 

[WeeboTech]

I've read somewhere that the real world performance of a Gigabit lan will be somewhere between 300Mb/s and 400Mb/s,  or between 3 and 4 times the speed of a 100Mb/s LAN.

 

When only the CPU and NIC are involved you can benchmark at up to 900MB/s.

This was an actual number I got from application to application no disks involved. Nic on PCIe bus.

On my other machine which was a Celeron M@1ghz with a PCI-X bus, I benchmarked at 700Mb/s.

 

The max drive speed I've seen has been 125MB/s. raw read speed.

My drives average around 100Mb/s.

 

 

[WeeboTech]

Thanks for numbers.  It definitely helps with understanding things.

 

The bargain hunter in me says go "WD Green", but the loyal part of me says go "Seagate" as I already run 4 Seagates now.

 

Might be decided by the ancient technique of "eeny meeny miny mo" 

 

The only drive I suggest spending the most on for speed related is the parity drive.

Go green for everything else unless it will be a heavily accessed drive.

 

WD Green on parity was a real bottleneck for my busy torrent system.

The day I upgraded to the Seagate 7200RPM 32MB cache 1.5tb, I saw a large improvement.

 

 

 

[lionelhutz]

For playing HD media, all the newer drives are fast enough. You need about 40Mbps.

 

Just pick whatever drive is the cheapest. Buying 3 drives at $20 savings each will pay for a motherboard or a SATA controller card or some other such part. It used to be Seagate had an advantage with their 5 year warranty. Now that they are 3 years just like everyone else that advantage is lost.

 

I could see a faster parity drive help if you will write to multiple data drives at once. Writing to a single data drive would limit you to that drive speed.

 

If you regularily write large amounts of data to the server then make use of a cache drive and gigabit networking. Let the server write to the protected array at whatever speed it can while you are sleeping or at work.

 

FYI, I have a single normal WD 500gig SATA drive in my HTPC, not a green bought about 1.5 years ago. I notice I can't even saturate 100Mbps network if accessing that drive for much else such as torrenting or even just watching some media off it.

 

Peter

 

[WeeboTech]

I could see a faster parity drive help if you will write to multiple data drives at once. Writing to a single data drive would limit you to that drive speed.

 

If you regularily write large amounts of data to the server then make use of a cache drive and gigabit networking. Let the server write to the protected array at whatever speed it can while you are sleeping or at work.

 

The parity drive should be the fastest drive you can afford within reasonable limits if you do not implement a cache drive.

 

I can say there was a measurable improvement by switching my parity drive from 1tb 5400 to 1.5tb 7200MB 32MB cache.

 

Although writing to a single data drive would limit you to that speed, use of parity makes this worse.

 

If I can write to a single data drive at 60MB/s or more, adding parity will drop this to 8-12MB/s.

When I changed my parity drive to 1.5TB 7200RPM drive this changed to 12-20MB/s depending on burst and ram usage.

 

This is from a local unprotected drive to a parity protected drive. The network never came into play here.

 

I write small to medium files all day with torrent. It was noticeable on how fast things changed with this switch.

[PhilH]

It used to be Seagate had an advantage with their 5 year warranty. Now that they are 3 years just like everyone else that advantage is lost.

 

That is definitely true if you buy OEM drives.

 

The last 2 1.5TB Seagates I bought, I bought at Best Buy. Just luckily caught them on sale & they were cheaper in price than the same drive in the OEM flavor at Newegg. The retail versions still have the 5 year warranty.

 

Just me but the extra 2 years of warranty makes me feel better.. 

[abq-pete]

One other thing to consider is:

 

Seagate Nonrecoverable Read Errors per Bits Read = 1 per 10E14

Western Digital Green Power Nonrecoverable Read Errors per Bits Read = 1 per 10E15

 

With drive and array capacity increasing, this is a factor worth considering in terms of reliability.  I originally had 6 of the Seagate 1.5.  But with the firmware fiasco and SMART reports indicating increasing error counts, I swapped everything to the WD Green 2TB.  Yes, I took a performance hit for parity activities, but I sleep a little bit better.  By the way, some Seagate Enterprise drives are rated at 1 per 10E16!

 

Regards,  Peter

[WeeboTech]

With drive and array capacity increasing, this is a factor worth considering in terms of reliability.  I originally had 6 of the Seagate 1.5.  But with the firmware fiasco and SMART reports indicating increasing error counts, I swapped everything to the WD Green 2TB.  Yes, I took a performance hit for parity activities, but I sleep a little bit better.

 

With 3 drives in a small array this is not that much of an issue.

 

What's missing here is "what SMART errors increasing error counts" what factors were there and how are the numbers normalized.

Many SMART numbers are normalized over time with other numbers.

 

The firmware fiasco was definitely an issue to consider.

If it were still an issue I would be against the Seagate drive.

I have not had any issue and I still run with the old firmware.

 

 

Monthly parity checks are highly recommended.

If you are doing them and have an array with less then 12 drives, I do not think the nonrecoverable Read Errors per Bits Read = 1 per 10E14 vs onrecoverable Read Errors per Bits Read = 1 per 10E15 should cause you to loose sleep. 

 

Let's face it,  there are people out there with 24 and higher RAID5/RAID6 arrays that take many days to expand and verify.

 

We're talking about unRAID where data is compartmentalized into spindles.

unRAID and it's methodologies, along with easy scan ability, is a highly resilient platform.

 

I've been doing monthly parity checks for a long time. I've not had any sync errors on my 1.5tb seagate drive.

 

If write performance is not an issue, I.E. occasional dumping to the file server, then save the $20.

 

 

 

[abq-pete]

I am probably overly cautious.  But back when I bought the drives (Feb?) I was running them continuously through the pre-clear script and watching as the various numbers (several categories whose names I forget now) continued to rise.  The folks here suggested that some of the drives (several of them showed the same characteristics even after firmware updates) should be exchanged, so I did just that.  After things seems to settle a bit, I installed them into the array.  After a few weeks I had my first sync error for no obvious reason.  I have had them in the past but they were due to hardware, shutdown or power issues.  In this case none of these were the case.  I lost confidence in the drives so I replaced them with the WD 2TB drives and I have not had issues since.  Of course this could be only my bad luck, but I thought I should share my experience.  Also, my array is at its capacity limit until a new beta is released that is reliable with more than 16+1 drives so the 10E14 number is important to me...

 

Regards,  Peter

[Joe L.]

I am probably overly cautious.  But back when I bought the drives (Feb?) I was running them continuously through the pre-clear script and watching as the various numbers (several categories whose names I forget now) continued to rise.  The folks here suggested that some of the drives (several of them showed the same characteristics even after firmware updates) should be exchanged, so I did just that.  After things seems to settle a bit, I installed them into the array.  After a few weeks I had my first sync error for no obvious reason.  I have had them in the past but they were due to hardware, shutdown or power issues.  In this case none of these were the case.  I lost confidence in the drives so I replaced them with the WD 2TB drives and I have not had issues since.  Of course this could be only my bad luck, but I thought I should share my experience.  Also, my array is at its capacity limit until a new beta is released that is reliable with more than 16+1 drives so the 10E14 number is important to me...

 

Regards,  Peter

As much as I hate to say this, but 10E14 is about 100T bits.  (If I did my math right)  If you've got an array filled with drives, every ten parity checks or so you will have processed that many "bits" (off of one or the other of the drives)  All it takes is one "bit" wrong to have that parity sync errors.

 

As you said, 1 error is too many... but this is the statistic on almost every disk in the average PC out there...  We just get to detect them... sometimes.

 

Joe L

[bblue]

From a reliability and longevity point of view, I would never buy another WD.

 

Over the last ten years I've probably installed around 120 drives between my own desktops and servers, and a few systems built for friends.  About 30% of all WD's I installed (200, 300, 500GB) were dead within three years.  Not too impressive for any drive, let alone one with a one year warrantly.  Over that same period of time I've had *maybe* TEN Seagate drives fail.  Total.  A couple of those were D.O.A or within a few days.  All were within the generous five year warranty (now three in some cases).

 

Despite the very annoying firmware hassles we experienced recently, there just isn't any other drive with this kind of reliability... not that I know of, anyway.  I have some that are going strong after 7+ years of almost continuous use.  Can't beat that.

 

--Bill

[PhilH]

I just had another WD drive die last night. That's about 5 in the last year. All of them were of the 500 gig variety. The manufacture date of the latest drive is December 10, 2007. Could have been a bad batch but who knows. 

[bubbaQ]

From the other side......

 

I've used primarily WD drives for a long time.  My first home server was a Windows NTAS box, with four 250G WD drives.  I used those same drives in several incarnations including my first unRAID build.  I finally took them out of service in the server, and retasked them to other uses -- 3 of them are currently in my unRAID test bench machine, and SMART shows over 50K hours on them..

 

I have also had my share of Seagates... and about half have failed.  One in my telephone system, and 2 in unRAID in recent memory.

 

Rather tan fixate on one name, just employ common sense:  1) Don't buy a new model of drive from ANYONE... wait 6 months for it to shake out any bugs or firmware fiascos.  2) Swap out drives when they hit 25K or 30K hours.  Wipe them and reuse them for something noncritical, or sell them on eBay. 3) never buy more than one drive at a time from the same source, so you never have 2 drives from the same batch.  4) Keep a spare on hand to replace a failed drive in an array ASAP.

 

I don't care about warranty because I will NEVER send a drive in for warranty repair because of the security issues with the data I have on my systems.  (Once unRAID can run with TrueCrypt support at the OS level, I'm willing to reconsider)

 

All hard drives fail... that is a fact.  Plenty of people like one brand more than another, and have "experience" data to back up their position.... but it is all just rubbish.  Look at LARGE surveys with LOTS of data -- not anecdotal experiences.

 

Remember that RAID is "redundant array of INEXPENSIVE disks" and they are expected to fail... RAID is a fault-tolerant platform.... embrace it. 

[spinbot]

Having to send a hard drive away for warranty that is loaded with porn might be an issue

 

So, UnRaid protects your data so concerns about failure aren't as lessened.    Out of curiosity, if one lost a 1.5TB drive full of data, how long would it take to rebuilt it after you install a new replacement?

[Joe L.]

Having to send a hard drive away for warranty that is loaded with porn might be an issue

 

So, UnRaid protects your data so concerns about failure aren't as lessened.    Out of curiosity, if one lost a 1.5TB drive full of data, how long would it take to rebuilt it after you install a new replacement?

That entirely depends on the number of drives in your array, and their speed, and the bus capacity of your motherboard.

Basically, it will be quite similar to the time it takes to do a full parity check.

[spinbot]

I'm waiting for parts to arrive next week to make my server, so i haven't had to do a parity check.  I'm guessing it would be a while.  Having a spare drive, equal to your parity drive would be handy I bet.

[bubbaQ]

Having to send a hard drive away for warranty that is loaded with porn might be an issue Smiley

 

Lots of more mundane things are more likely.

[spinbot]

Oh... I get ya.  Porn with oneself in it ( aka more sensitive data ).  hehehe  Just kidding. 

 

My UnRaid will be used as a Media Server, so I have nothing sensitive like that.  My only issue is with breaking copyrite laws ( shhh... I don't own all the mp3's on my PC ) and having WD or Seagate call the Recording Industry on me!

[PhilH]

Oh... I get ya.  Porn with oneself in it ( aka more sensitive data ).  hehehe  Just kidding. 

 

My UnRaid will be used as a Media Server, so I have nothing sensitive like that.  My only issue is with breaking copyrite laws ( shhh... I don't own all the mp3's on my PC ) and having WD or Seagate call the Recording Industry on me!

 

LMAO Good one...

 

Up above about keeping a spare drive equal to the size of the Parity drive is a good idea. Every time I tried that though I used the spare drive for something else..