Drobo

FW800 transfer speeds on the Drobo

I am copying data over to my new Drobo (2TB, 1TB disks installed) and notice that the transfer speeds over FW800 seems rather slow - comparable to USB 2.0 transfer speeds. I am transferring data from a FW800 drive connected via the FW800 port on the Drobo, which in turn is connected to my Mac’s FW800 interface.

I intend to use the Drobo for all my audio editing and audio recording and worry about data transfer speeds. I have used another FW800 external drive to do the same thing without any problem, the Drobo just seems slower.

drobo is pretty slow

which model is it - just a V2?

ive never seen one run out of bandwidth over USB2. so FW800 will make very little difference

Any idea why this is so slow? I have the dr04dd14

[quote=“mapexvenus, post:3, topic:2792”]Any idea why this is so slow? I have the dr04dd14
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The Drobo processor isn’t very fast, and the internal Drobo Magic Software is fairly complicated and much more resource-hungry than traditional RAID.

The Drobo processor isn’t very fast, and the internal Drobo Magic Software is fairly complicated and much more resource-hungry than traditional RAID.
[/quote]

So then probably not a good idea to use it for the purpose that I bought it. If the drive is unable to keep up with the requirements of the software then that will be problematic.

Audio editing isn’t that transfer-intensive, though it is very latency-sensitive.

Performance quickly goes downhill as you start pulling multiple files simultaneously, though.

So it’ll depend on your individual use. It might be that you end up using Drobo for archives and backup snapshots, perhaps 1 or two source streams and use other drives for scratch.

Bhiga and Docchris, have you guys seen your posts counts? That’s 1,718 vs. 1,717 :slight_smile: Even the joined date is the same. Do you have some wager ongoing? :slight_smile:

i must post more!!!

Is there an alternate solution to Drobo that I can use both for scratch and archiving?

I never really looked to see how close our counts are, but now that you bring it up it’s quite amusing!!

and we got there with no postings of beeeewbs or the like! :wink:

Seriously though, Docchris has caught me (and let me down easy) in a number of befuddled moments, so I say he’s the wiser one. :smiley:

(Dang! I should’ve split this into two posts, then we’d be even! Hehehe)

If you’re only pulling a few streams, a DroboPro or DroboElite (whatever it’s named today) may do nicely.
If you’re pulling a number of streams, you may need something with a more heavy-duty processor or more-sophisticated physical array management (remember that RAID doesn’t eliminate seek latency issues, it just lowers the impact by increasing throughput). There are competing DAS solutions from QNAP and Synology that provide more throughput and a different level of management (whether that’s good or bad depends on the user).
Suffice it to say, however, that the units below Drobo Pro (such as the Gen2 Drobo you have) really do better with single-stream/single-user type tasks compared to multi-stream/multi-user tasks.
(read on further before you jump ship though)

Also, as it seems your Drobo is fairly new (I assume that’s why you’re copying data to it), be aware that it takes 24-48 hours for Drobo to optimize itself, especially after a large data-copy such as what you’re doing.

Furthermore, Firewire is shared bandwidth, much like SCSI, so if you’re doing transfers between two FW devices, they end up sharing space on the same pipe.

So in this case, you might find it faster to connect the Drobo to your system’s USB port and get unobstructed (or at least less-obstructed) throughput on the two buses - USB for writing and Firewire for reading.

If you happen to have another Firewire interface (not just port, but actual controller) you can connect to, having each device on its own bus would give you maximized Firewire transfer speed.

Thank you very much for your detailed response. I really appreciate it!

My Macbook Pro has only one controller, but two ports. One of them is a FW400, and the other is FW800. My audio interface goes into the FW400 and the Drobo, the FW800. For best results I should probably upgrade to a Mac Pro which has multiple FW800 ports, which I assume are all on separate controllers. The other option would be to use the USB port with the Drobo, and the FW port for my audio interface. Definitely something to thing about.

I should add that my Drobo will also be used as storage for my iTunes media, and other media which now is worth several hundred dollars. The goal is to protect that investment and also stream content to the various Apple TV’s and iPads that I have at home via the Mac it is connected to.

Based on what I have learned so far, I may decide to retain the Drobo to serve and backup / protect my iTunes content and audio files, but will probably use another HDD as scratch disk for audio production.

I want to add that Drobos tend to have very unpredictable and variable throughput rates, especially as the hard drives fill. On a good day my V2 gets about 14MB/s throughput, read and write.

On a bad day, or during a bad 15 minutes of a good day, I might get 5MB/s. And it might go back to normal in a few minutes. It might stall out entirely, with throughput below 1MB/s, for no comprehensible reason.

Because the internals are very proprietary no one understands why this happens. Some people think they run faster when at less than 50% capacity. Some people think disk upgrades slow it down and it can be sped up by reformatting a fresh volume and reloading data. All this is anecdotal.

Edit: the critical point is that even if it works well for you NOW, with a fresh and lightly loaded volume, it may not work well next week or next month or next year.

I’m just suggesting I would not use a Drobo, especially a V2, for any app that requires fast streaming speeds in order to function properly. You’d be better served with a simpler, faster disk for your working data and maybe use the Drobo purely for backup of finished files. I think you are heading in that direction now; I wanted to help you cement your decision :-).

Hmm… according to some quick research, as long as the bus is operating in bilingual mode, you should have maximum throughput from both devices (ie, the bus doesn’t slow down to FW400 speed because you have a FW400 device connected as long as you’re not daisy-chaining through a FW400 device.

Not sure the mac Pro has multiple controllers - it’s quite rare to see a system with multiple separate FW controllers unless they’re add-in cards.

Just as NeilR points out, my Gen2 Drobo is “bursty” on transfers. So you may be seeing some slowdown based on FW devices “clogging the pipe” for short bits. We see this happen in the video world (where I work) and it applies to audio as well - since real-time data transfer (low-latency) is critical, it’s better to have a slower, constant data flow, compared to intermittent bursts. While the average transfer rate may be the same in both cases, the bursts cause latency that can mess things up.

Say you’re in an underwater chamber. You need to exchange 7.5 liters of oxygen per air. The air system on the surface sucks out the stale air and pumps new air down. If the system provides a constant flow of 7/5 liters/minute, it’s easy to breathe, no problem. But if the system exchanges 37.5 liters of air every 5 minutes, you’ll likely die (or at least pass out) before the next inrush. Probably not a scientifically-accurate example, but you get the point.

In the case of data-flow, “bursts” from one device can interrupt the nice steady flow from another, and a “stall” even if it’s made-up-for by higher data throughput later, can be problematic.

Here at my office we’ve edited medium-bandwidth video from our DroboPro. But, that’s a DroboPro, not a Drobo Gen1/Gen2, and our editing software employs a cache that lets it “ride through” short interruptions.
If your software has some kind of pre-caching/buffering function that may help, but I still agree with NeilR.

At the very least, your current Drobo would make a very nice off-site/lock-away backup. If I had 99 Drobos (I think there was a recent contest/request about this on the Drobo site), a number of them would serve that purpose, littering my associates with my backups, haha. At least it’d give me reason to get out of the house and visit people regularly. :slight_smile:

Just to be clear, my comments had nothing to do with interface latency but with the fundamental behavior of the Drobo. I use USB 2.0 on Win 7 and occasionally XP. Although other USB devices (mainly simple single drive external enclosures) have variances that can be chalked off to USB/latency issues, none of them slow down as much or as long as my Drobo does on occasion. There are two distinct potential issues here and neither are favorable for high speed editing.

drobo will always be much much faster when it is less than (about) 50% full and it can just rely on duplication rather than parity calculation in order to provide redundancy

Chris,

I used to agree with your thinking, but in the case of 3 or more identical drives I am no longer convinced the Drobo mirrors the data at any point in time, even when the array is new and fresh.

In the case of mixed capacity drives that may be the case but it would likely only occur after all the common space across the drives is fully used and only “odd” space is left that cannot be parity striped across all the volumes. There are also endless other upgrade scenarios that would result in mirroring but they are all related to conditions that currently prevent the array from parity striping across all the existing drives at some point in time.

I don’t state that as a fact, only as an opinion based on reading the publicly available patent discussions about mirroring and when it might occur, and some discussions here that lead me to question my earlier belief that the Drobo mirrors first.

If you have any hard evidence that my current thinking is wrong I’d like to hear it because I have a very open mind on this issue and I think it is an important issue in terms of throughput and the advisability of trying to improve throughput with excessive capacity.

Indeed, I wasn’t talking specifically about interface latency either, but rather the overall data arrival latency - whether it’s introduced by the device (just plain slow feed) or its interaction with the interface (one device interrupting the flow of another).

According to ViceVersa Pro’s meter (doing file copies of real data, so the size varies from lots of tiny <1MB files to >=6 GB files), my USB-connected Gen2 has highs around 25-30 MB/sec, and lows around 2 MB/sec. Well below both USB 2.0 and Firewire 400 max speeds, but it’s fast enough to play Blu-ray content, which means at least 6.75 MB/sec from a single ISO in a single-task scenario.

Unless I’m really off today, 48KHz, 24-bit, stereo audio is only 288 KB/sec (bytes, not bits), even 96KHz, 24-bit, stereo is only 1.152 MB/sec, so it’s pretty darn low in the grand scheme.

If you were doing real-time video editing, I’d definitely say look elsewhere. But for audio, I think this needs a real “fit for use” test. Give it a stress-test in your use environment and see how it performs in your situation. Throw your “toughest” audio project on there and see how it does. Then make the project 2-3 times “heavier” and see how it fares.

If it only performs slightly better than what you normally need, or is already struggling to keep up, then you probably want to look at something else for your scratch/working storage as Drobo isn’t going to get any faster as it fills up.

So the question really is not so much whether it’s fast or slow but rather whether it’s fast enough and how long it’ll stay that way.

Thank you everyone for your responses. For now, I have decided to use the drobo to be my iTunes storage. I will test whether the device is useful for audio editing when I have some time this weekend.

Hi (sorry for my english i write from italy),

i’ve drobo from 2 days and suddenly my drobo 2 nd with 4 HD of 2 TB is very very slow.

is connected by FW 800 with macosx Lion.

2 days ago the trasnfer rate was ok, but now is terrible slowly.
Drobo is slow also with usb 2.0 connection.

With other external hd the trasnfer rate is fast, also with usb 2.0

thanks

@siryayo
It could be hard drive slowing down due to drive errors. Download the diagnostic log from Drobo Dashboard and send it to support - they will be able to tell if you there is a drive slowing things down.