I have a drobo 5D with 5 x Seagate Barracuda 3TB(ST3000DM001).
the connection is thunderbolt and computer model is mac book pro early 2011 13" - dual core corei5, 8GB main memory, 120GB SSD, 320GB HDD(replaced with its CDROM drive)
First time when i just bought it, it was really fast(usage less then 10%).
Now it is really slow, transfer speed is average 80MBps(usage 70% or more)
What is the problem ? Drobo ? or HDDs ?
What are you doing that runs at 80MB/s? Are you reading small files, writing large files, etc?
Did you just copy a lot of data to your Drobo? Maybe it hasn’t finished optimizing the locations.
Is one of the volumes getting full? HFS+ becomes less efficient when free space is very low.
About how fast was it before?
Thank you for your reply.
I have ran Black magic performance tool(5GB read/write)
write speed was over then 200MB/s but now is 80MB/s
the drobo 5D was formatted as 16TB HFS+.
8TB full and Max capacity is 10.89TB
Are there other processes accessing the Drobo, like Spotlight indexing it, or antivirus scanning it, for example?
Benchmarks test specific aspects of performance. Unless the benchmark reflects your normal use patterns, I would not worry about it very much.
In this case, I wonder if normal use benefits from data tiering (if you have an SSD installed). The benchmark would not show this. On the other hand, maybe you ran the benchmark to quantify an experience that your Drobo is slower.
If you were able to write at 200MB/s until now, I’m jealous and my DroboPro is feeling most insecure. 
[quote=“dyseo, post:3, topic:119633”]write speed was over then 200MB/s but now is 80MB/s … 8TB full and Max capacity is 10.89TB
[/quote]
That means it’s about 80% full and the performance dropped 60%. That’s unusual: individual spinning drives drop about 50% at 99% full in my experience, and usually deliver about 70% of “new” performance when they’re only 80% full. In other words, Drobo should do about 140MB/s when 80% full.
Is it perhaps too fragmented? Have you tried defragmenting it?[hr]
[quote=“rdo, post:5, topic:119633”]If you were able to write at 200MB/s until now, I’m jealous and my DroboPro is feeling most insecure.
[/quote]
Just today one gentleman posted elsewhere that he is getting close to 300MB/s via Thunderbolt in Windows, with five ST2000NC001 drives in single parity mode.
That surprised me - always thought of Drobos as underperforming. This thread however makes me concerned whether they can sustain good speeds over at least 80% of the capacity.
Defragmenting tools are designed to operate on physical storage volumes, not virtualized ones like Drobo provides.
Don’t defrag a Drobo. http://support.drobo.com/app/answers/detail/a_id/11
Agreed - don’t defrag (not that you should on a mac anyhow ;-).
Fair enough. Is there a way to still see if the volume is fragmented and that Drobo “intelligence” is at work keeping it well defragged?
If not, how can we be sure those low speed numbers aren’t a result of Drobo dropping the ball on defragging?
I would postulate that any “defragging” would be akin to the auto maintenance that the Drobo does in the background which unless I’m missing something is and will forever be a mystery. I know my Drobo 5D took forever to finish “performing maintenance” which did slow things down. You could always here it moving stuff around until one day (a month later?) it finally chilled out and acted like a Good Drobo.
If an SSD is involved, this further complicates things as I’m almost certain no maintenance or “garbage collection” is being done on those…per the ever dwindling SSD Life Meter on the Drobo Dashboard that goes down exponentially each week. I’m now on my second SSD.
Either way, I should ask…is the green activity light blinking when at rest? Is it sitting at idle when performing these tests? Is anything like Crashplan or Time Machine tying up the Drobo?
[quote=“Zathrak, post:10, topic:119633”]I know my Drobo 5D took forever to finish “performing maintenance” which did slow things down.
If an SSD is involved, this further complicates things as I’m almost certain no maintenance or “garbage collection” is being done on those…per the ever dwindling SSD Life Meter on the Drobo Dashboard that goes down exponentially each week. I’m now on my second SSD. [/quote]
Thanks Zathrak, this is great info. Is there a way to pause or suspend that “performance maintenance”? If not, it’s a showstopper for any real editing work, unfortunately. Also curious if using enterprise grade SSDs like Intel S3700 (which are supposed to take a lot more writes than consumer grade ones) will have a longer life. Don’t think they’re available as mSATA though.
[quote=“beans, post:9, topic:119633”]
Is there a way to still see if the volume is fragmented and that Drobo “intelligence” is at work keeping it well defragged?[/quote]
This information is recorded in the diagnostic logs. Drobo Support will decrypt those logs and tell you what they think, but they will not provide actual data from your diags.
So, no.
Gotcha, thanks!
(P.S. No “+1” or “kudos” or “like” buttons on this forum? Dudes, how am I gonna survive here? :p)
Agreed, Drobo will have to interpret the data and subsequently not give it to you. It doesn’t matter how much you bribe them, they won’t release it. I’ve tried. 
I don’t want to discourage you from the Drobo because I do love the 5D for my implementation, but it does need to spend countless hours up front organizing everything especially after a massive data dump (which is what I did). After that’s done and in single disk protection mode, mine performs about as fast as any old traditional 7200 RPM HDD would, despite my having a 64GB mSATA. While nothing is definitive there aside from a limited write capacity on consumer SSDs, you may want to check out the link below for some discussion on the consumer vs enterprise topic.
Ouch. Drobo nearly fails an SSD but doesn’t show detailed SMART info?