External Hard Drive extremely slow

Poki

macrumors 65816
Original poster
Mar 21, 2012
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Hi,

just wanted to transfer some files today and noticed my three year old WD MyBook 3.0, connected with USB 3.0 to my Mac Mini, is extremely slow. Blackmagic Disk Speed Test says it's just over 2 MB read / write.

My first thought, of course, was that the disk is malfunctioning. But after restarting my Mac, it was back up at 90 MB/s read / write. Just a few minutes later, it's at 2 MB/s again.

Why could this be? I hope the HDD isn't defect since I don't have a backup yet - I planned to get a MyBook Thunderbolt Duo 8TB next month for that reason ...

Thank you for any help!
 

Poki

macrumors 65816
Original poster
Mar 21, 2012
1,317
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How full is it? Have you tried disk utility's repair disk?
About 1.8 TB full of 2 TB. I'll offload most of it to the Thunderbolt Duo once I have it, but still - there is 10% storage free, so it can't be the reason it only transfers at 2 MB/s, can it?

Disk Utility says everything is okay.
 

ColdCase

macrumors 68030
Feb 10, 2008
2,995
151
NH
Yeah some drives slow down quite a bit at 80-90% capacity, mostly because its using the slow area of the platters and perhaps dealing with some error correction and fragmentation. It could have some bad blocks that get harder to deal with the less free space there is.

If you are worried, I'd try to not use the drive much until you get the data off. Then erase it.
 

MCAsan

macrumors 601
Jul 9, 2012
4,556
419
Atlanta
I replaced my 3.5" drives with Seagate 6TB 128MB cache units. Good performance, and reliability so far.
 

Poki

macrumors 65816
Original poster
Mar 21, 2012
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I think I got the culprit. The past couple of days, I've been transcoding video material stored on my external hard drive using Quicktime. Of course I paused any operation while running the disk speed test, but there seems to be a bug in Quicktime in Yosemite which makes the external drive unbearably slow while playing a video stored there.


Yeah some drives slow down quite a bit at 80-90% capacity, mostly because its using the slow area of the platters and perhaps dealing with some error correction and fragmentation. It could have some bad blocks that get harder to deal with the less free space there is.

If you are worried, I'd try to not use the drive much until you get the data off. Then erase it.
Sure, I know that. But even a 90% full drive has to be faster than 2 MB/s. I mean.. 2 MB/s! That's sooo slow, you can't do anything with that speed.

I replaced my 3.5" drives with Seagate 6TB 128MB cache units. Good performance, and reliability so far.
I appreciate that tip. However, I want an actually safe method to store my data, and a RAID drive seems to be the only option. And the WD My Book Thunderbolt Duo is the cheapest 8 TB (4 TB when mirrored) solution I've found. Sure, the USB version is even cheaper, but I prefer Thunderbolt if possible due to it not blocking up any port and not needing any hubs. If anyone knows a RAID solution with better value, please tell me.
 

matreya

macrumors 65816
Nov 14, 2009
1,286
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I appreciate that tip. However, I want an actually safe method to store my data, and a RAID drive seems to be the only option. And the WD My Book Thunderbolt Duo is the cheapest 8 TB (4 TB when mirrored) solution I've found. Sure, the USB version is even cheaper, but I prefer Thunderbolt if possible due to it not blocking up any port and not needing any hubs. If anyone knows a RAID solution with better value, please tell me.
Personally, if it was a choice between a WD product and something else, I'd go with something else :)

The unit you're looking at, would have at best WD Caviar Red drives, which IMHO aren't as reliable as HGST drives (ironically owned by WD, but operated as a separate entity).

I have one of these units, and with a couple of 4TB HGST Deskstar NAS drives in it, it would be more pricey than the WD unit, but last longer...

http://eshop.macsales.com/shop/Thunderbolt/External-Drive/OWC/Elite-Dual-RAID
 

Poki

macrumors 65816
Original poster
Mar 21, 2012
1,317
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Personally, if it was a choice between a WD product and something else, I'd go with something else :)

The unit you're looking at, would have at best WD Caviar Red drives, which IMHO aren't as reliable as HGST drives (ironically owned by WD, but operated as a separate entity).

I have one of these units, and with a couple of 4TB HGST Deskstar NAS drives in it, it would be more pricey than the WD unit, but last longer...

http://eshop.macsales.com/shop/Thunderbolt/External-Drive/OWC/Elite-Dual-RAID
Ironically, the 8 TB WD MyBook Thunderbolt Duo comes with two HGST Deskstar 5K4000, as opposed to the WD Caviar Green in the lower capacity models. In addition to that, I always bought WD drives and never had a single one fail, so I guess they're okay anyway.
 

ColdCase

macrumors 68030
Feb 10, 2008
2,995
151
NH
You know recently I've had more problems with HGST drives (4TB) than WD branded drives, even less issues with large capacity Seagates (no issues). I've abused several lower capacity HGST drives without issues but have had to RMA two out of my two 4TB HGST drives. There may be a different pecking order above 3TB than below.
 

bennibeef

macrumors 6502
May 22, 2013
340
161
I appreciate that tip. However, I want an actually safe method to store my data, and a RAID drive seems to be the only option. And the WD My Book Thunderbolt Duo is the cheapest 8 TB (4 TB when mirrored) solution I've found. Sure, the USB version is even cheaper, but I prefer Thunderbolt if possible due to it not blocking up any port and not needing any hubs. If anyone knows a RAID solution with better value, please tell me.
If you go for the MyBook and you want to use the 8TB (striped) then better dont think about that beeing a safer way, more a unsafer way. You just doubled your chance of a hard drive failure and you loose all(!) your data on the MyBook if one of both drives is failing.
 

Poki

macrumors 65816
Original poster
Mar 21, 2012
1,317
903
You know recently I've had more problems with HGST drives (4TB) than WD branded drives, even less issues with large capacity Seagates (no issues). I've abused several lower capacity HGST drives without issues but have had to RMA two out of my two 4TB HGST drives. There may be a different pecking order above 3TB than below.
I guess it's all about luck as much as actual quality. With a mirrored system with three years of warranty, I just hope that not both drives fail at the same time. I can't afford an additional backup layer for the majority of the data stored there right now. But really, it should be better than storing anything just on a single drive.

The only hard drives I've always had problems with are the Fujitsu ones. I don't know why, but these always failed within a couple of months. HGST, WD and Seagate all seem to have a relatively low failure rate, so I'm fine with either of them.

If you go for the MyBook and you want to use the 8TB (striped) then better dont think about that beeing a safer way, more a unsafer way. You just doubled your chance of a hard drive failure and you loose all(!) your data on the MyBook if one of both drives is failing.
I don't stripe anything, I'll use it mirrored. 4TB is enough for another year or so, and then I'll just add another MyBook TB Duo and configure them RAID 10. Should work perfectly fine - in theory.
 

Poki

macrumors 65816
Original poster
Mar 21, 2012
1,317
903
The LaCie 2big Thunderbolt 2 seems to be a great alternative to the WD MyBook Thunderbolt Duo, though. More durable aluminum case, USB 3.0 as an option when transfering data to computers without Thunderbolt (although that's not really a requirement), and faster transfer speeds even at RAID 1 due to 7.2k RPM hard drives. Will have to look closer into that one too.
 

thedeske

macrumors 6502a
Feb 17, 2013
963
58
You know recently I've had more problems with HGST drives (4TB) than WD branded drives, even less issues with large capacity Seagates (no issues). I've abused several lower capacity HGST drives without issues but have had to RMA two out of my two 4TB HGST drives. There may be a different pecking order above 3TB than below.
Same Ol story. I've had very good luck with many 4tb Deskstars in the past 3 years.

I tend to believe the brand is less important in general and specific production runs from any manufacturer can suffer QC problems. One year WD is the darling (on the nets) the next is Samsung Spinpoint, then HGST, then ... Take your pick. Oh, Seagate's in there somewhere.

We consumers would love to lock onto a "Best" brand, but I don't see one.
If I claim that Samsung has the most reliable consumer SSD, it will eventually burn in Hell & Intel will take over for a few months (example)

The only thing long experience teaches is to Have More Than One Drive - JIC ;)
 

Ray2

macrumors 6502a
Jul 8, 2014
695
151
You know recently I've had more problems with HGST drives (4TB) than WD branded drives, even less issues with large capacity Seagates (no issues). I've abused several lower capacity HGST drives without issues but have had to RMA two out of my two 4TB HGST drives. There may be a different pecking order above 3TB than below.
I've had excellent results from Hitachi/HGST. I started using them about 15 years ago. Now have 11 tb worth of them. Never lost one. One old ATA drive runs torrents 24/7. Been doing so for about 10 years and I can't believe its still chugging along. Overheated once, let it cool down and its been chugging along for 2 years since.

Thanks for the comment about their 4tb drives. I just saw them (perhaps 1) on sale at OWC for $108. By the time I finished thinking about it, they/it was sold. That's an awfully low price and I wonder if they've had some issues with them.
 
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