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  #1  
Old 09-16-2019, 02:32 PM
juh juh is offline
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Default OWC dock data transfer rate

Hello

I'm planning to buy a thunderbolt2 dock (OWC double dock) to plug in my Macpro 2013, with two SSD drives inside (2To each).

First question, is it a good dock ? No disturbing noise ?

Then I need to know if the data transfer rate is the same with one or two drives ? Or is it divided by two with one drive in each bay ?

Thank you!
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  #2  
Old 09-16-2019, 04:40 PM
Darryl Ramm Darryl Ramm is online now
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Default Re: OWC dock data transfer rate

Can you provide a URL to the exact device you are looking at?

What will you use this storage for? Do you have performance needs/problems now?

Unfortunate that Trashcans have really crippled IO. The fastest storage you can can get on a trashcan is the internal SSD. If you need fast disk you are likely better off running sessions off that than any external drives.... if you have space. And then moving inactive sessions to external drives. Disk cache can also help greatly, so make sure that is enabled (set to size not “normal”).
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Old 09-17-2019, 12:45 AM
juh juh is offline
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Default Re: OWC dock data transfer rate

Hello Darryl

Here's the URL :
https://www.owcdigital.com/products/...-thunderbolt-2

Currently I'm working with 3 external drives (7200 plugged in 3 USB ports).
I'm a composer so I use many sample libraries, that's why I'd like to use SSD drives...
My sessions are located in one external drive, I could try to transfer the active ones in my internal SSD (almost full...)

So it's not a good idea to use thunderbolt ports with external drives using PT ?
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Old 09-17-2019, 07:55 AM
climber climber is offline
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Default Re: OWC dock data transfer rate

Quote:
Originally Posted by juh View Post
So it's not a good idea to use thunderbolt ports with external drives using PT ?
Why would you think that? I’ve been doing it for the past 6 years.
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  #5  
Old 09-17-2019, 09:24 AM
jwilkers jwilkers is offline
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Default Re: OWC dock data transfer rate

I use that dock with 5 different drives (all spinners) and no issues at ALL.
Connected to a 2014 MacBook Pro
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  #6  
Old 09-17-2019, 09:47 AM
juh juh is offline
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Default Re: OWC dock data transfer rate

Quote:
Why would you think that? I’ve been doing it for the past 6 years.
Quote:
I use that dock with 5 different drives (all spinners) and no issues at ALL.
OK so that's a good news for me.

Is a dock better than an external drive (with usbc output) plugged via a usbc/thunderbolt adaptator ?

And does the data transfer rate is the same with one or two drives in the dock ?

Thanks a lot
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  #7  
Old 09-17-2019, 12:10 PM
Darryl Ramm Darryl Ramm is online now
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Default Re: OWC dock data transfer rate

Quote:
Originally Posted by juh View Post
OK so that's a good news for me.

Is a dock better than an external drive (with usbc output) plugged via a usbc/thunderbolt adaptator ?
The dock internally is SATA III with a not great Thunderbolt to SATA III adapter chipset, which as you expected is actually going to give ~ the peak performance of a single drive. (bandwith and IO rates will be affected differently but I don't want to go down that rat hole).

These docks are not really intended for long-term use with drives. I have several of the similar Startech docks and they are very handy for cloning/swapping drives etc. I would personally not want one on my desktop for long term use, too fragile/bumpable. A bit too easy for other people to touch or remove the drive etc. .. and don't work for me wanting to have more easily portable external drives. You asked about noise... there is no fan, these are passively cooled, helped by the drives being vertical.

You are asking about performance and mostly for samples. But it's had to guess what is really going on/ what you really need here. Are you having problems getting samples to steam? Or startup/load time it too slow for cached samples? How much of a problem are you having and how much money do you want to spend?

You are looking at SATA SSDs, you can get more performance using PCIe/NVMe drives attached via Thunderbolt, you might still be able to find some enclosures, or maybe more likely end up using a PCIe expansion chassis... not a lot of choices compared to Thunderbolt 3.. where the market has gone, and unfortunately those devices are not backwards compatible with Thunderbolt 1/2. And expansion chassis have fans which might be a problem for you. But do you need to do all that messing around?

Sonnet had a nice Thunderbolt 1/2 PCIe NVMe based Fusion drive (awful name - not related to stupid Apple Fusion drives), but that's been replaced with a Thunderbolt 3 drive... and that's not compatible with the Trashcan. I wish Sonnet still made those for trashcan users. Other vendors had similar, I don't know of one still in production.

But again we are focusing on performance. And you can quickly end up building an exotic/complex storage system that you don't really need. How much performance do you need? How serious an issue are you trying to solve? How much space do you need? How much money do you want to spend?

If SATA SSD performance is all you want then my usual starting point would be to look at Samsung T5 SSDs. They are USB 3.1 Gen 2, you loose a little running them at USB 3/3.1 Gen 1 speeds. The Trashcan has four USB 3 ports and in yet another appalling IO design limitation they all share a single PCIe 2 lane, which will also might start to cap performance of two good SATA III drives. ... so as you asked, you could go for a Thunderbolt to USB adapter. Apple does not make a Thunderbolt 1/2 to USB adapter. You can find a third party dock that does Thunderbolt 1/2 to USB 3. I expect Thunderbolt 1/2 to USB docks/adapters you can find are likely to only do USB 3/USB 3.1 Gen 1 not USB 3.1 Gen 2, which again, will cap performance of a T5 slightly... but also be careful of cheaper docks/adapters and how much bus power they can pass to say two bus powered T5 drives.

And at the very simple extreme you might be able to start by just grabbing a 2TB single little Samsung T5 drive and sticking it into one of the USB 3 ports on the back of the trashcan. (But I suspect you need way more than 2TB). If nothing else that might be a good starting point and then if you need more performance in future look at a Thunderbolt to USB 3 dock to hang multiple of the T5 off. If you need lots of TB then the T5 will not be as practical as say using a 4TB Samsung 860 Evo in an enclosure/box.

You can look at larger "RAID" style enclosures, some of those have the same performance scaling issues as the dock mentioned. Thunderbolt 1/2 was a new frontier and lots of vendors did not do great performance designs. And if you are noise adverse the cooling fans may be an issue.

There used to be Thunderbolt 1/2 to SATA and Thunderbolt 1/2 to M.2 PCIe drive enclosures made, but the ones I were aware of/know worked for people are no longer available. Other folks may be able to recommend something.

Quote:
And does the data transfer rate is the same with one or two drives in the dock ?
No. It's going to be closer to the maximum performance of a single drive. Which will still likely be faster than two of your current HDDs. I was looking for the actual chipset that dock uses, could not find it but there are reports of this performance issues. e.g. https://macperformanceguide.com/Revi...DriveDock.html.

---

And back to the internal drive... You can upgrade that to 2TB or 4TB via OWC and maybe other vendors, and a 2TB PCIe 2 x 4 lane drive is the fastest you can get off the Trashcan. OWC are currently sold out of the 4TB drive. https://eshop.macsales.com/item/OWC/SSDA13MP4.0K might be worth asking them when they what is happening. You can get similar 4 x PCIe 2 lane performance if you could find a suitable Thunderbolt 2 to PCIe SSD adapter/enclosure.

Personally if I wanted maximum overall storage performance I'd be upgrading the internal SSD and then adding one or more AKiTiO Thunder2 PCIe Box with a Samsung 970 EVO 2TB M.2 SSD drive installed on on a PCIe slot card adapter... I like that as it give me choices of M.2 drives.. PCIe 3 M.2 drives will all work in the chassis. I could upgrade the M.2 drives later, and 4TB M.2 drives will not be far off. That's a nice high performance and relatively low cost but bulky and possibly noisy option.

It's weird that the old Cheesegrater now has much better PCIe/NVMe SSD expansion options than the trashcan. Apple unfortunately really lost the thread with the Trashcan.
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  #8  
Old 09-18-2019, 05:45 AM
juh juh is offline
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Default Re: OWC dock data transfer rate

Thank you Darryl for your detailed answer.

First I'd like to give you more precision about my configuration : as I said I have 3 external HDs plugged in 3 USB ports. The 4th USB port is used for 7 usb devices (via 2 usb hub).
I have 3 VGA computer screens connected to 3 thunderbolt ports (with VGA adaptor). And an Apollo 8 audio interface connected to a thunderbolt port.

My sessions regularly bug (PT quits, or the cursor becomes spinning rainbow and I have to force quit). I don't really know the reason, but it mostly happens with sessions containing a lot of samples loaded in several instances of Kontakt, or with some virtual instruments using high CPU. So maybe it's a cache memory problem or other reason ... I really have no idea.

My HD's sizes are 2x3To and 1x2To. I'd like to replace just one or two of them with SSD, and transferring my largest sample libraries on.

The reason why I want to change is the loading time, which sometimes is really too long.
And I believe that my system would be more stable by freeing some USB ports (but maybe I'm wrong..). So I'd like to avoid using SSD drives with USB ports...

Concerning the money I could spend, I would say between 500€ and 1000€, depending on the gain of performance...

I have a few more questions :

The 4 USB ports share only one PCI bus. Does it mean those 4 USB ports are the same than a hub ? So all usb devices have to share only one USB bus (500MB/s) ?? If so, data transfer rate is probably overloaded and may cause some of my bugs ?

Actually I don't really need a portable drive device. Does a Thunderbolt2 PCIe Box is really better than a SSD connected with an adaptor USBC->thunderbolt2, like the Samsung T5 ? (https://www.apple.com/fr/shop/produc...-thunderbolt-2)

Than you for your help
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  #9  
Old 09-18-2019, 12:58 PM
Darryl Ramm Darryl Ramm is online now
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Default Re: OWC dock data transfer rate

OK lots here. Let me answer your questions directly and then I'll reply with more handwaving to your general problem. And with what might be Kontakt related issues many others here will be able to help better than I can.

Quote:
Originally Posted by juh View Post
/snip/

I have a few more questions :

The 4 USB ports share only one PCI bus. Does it mean those 4 USB ports are the same than a hub ? So all usb devices have to share only one USB bus (500MB/s) ?? If so, data transfer rate is probably overloaded and may cause some of my bugs ?
Yes. That is one insanity of the trashcan. The design focus seemed to be "small and quiet" and dual GPUs... the GPUs ate 32 PCIe lanes leaving almost no other spare, including the IO chipset provided PCIe ports. So you end up with a single (500MB/sec) PCIe 2 lane hanging off the IO chip driving a USB 3 host controller. It's not quite a normal hub, they should be a little bit more efficient that say using a USB hub connected to a single USB 3 port, but yes we are really talking about ~500MB/sec maximum bidirectional bandwith for all the USB connected to those USB 3 ports on the back of the Trashcan.

Wether data transfer is currently "overloaded" or not: A single 7200 rpm SATA III hard disk drive (not SSD) can deliver at most around 150 MB/sec sustained performance. (That can burst up close to the SATA III limit of 500MB/sec if reading out of the on-disk cache. I do not expect the on-disk cache to be relevant here). So if all you have is 3 x 7,200 RPM drives connected to your trashcan it is unlikely the USB implementation there is going to cause you a slowdown, or any other problem to happen... except just slow load times for cached plugins or problems streaming plugins if you are doing a lot of stuff... but you are running into the limitations there of the HDD not the USB implementation.

Now if you go USB... yep a single little drive like a ~$100+ Samsung T5 could (when used with a program well written to do efficient IO) consume all the USB bandwidth on a Trashcan. So if I was looking at putting multiple SATA based SSD drives on a Trashcan and wanted to maximize performance I'd like to avoid having them all on USB.

That does not mean you might not see significant decrease in load time by going to say a single good SATA based SSD on a USB port. Not all you plugin libraries on different drives may be in use in a session, they may not all load at the same time etc. You might move the most frequently used library to say a single T5 drive attached to the USB and see a significant reduction in load times/increase in streaming performance. You are moving from high latency HDD to low latency SSD--and with sample load times disk "seek" latency can be a significant factor, it's not just bandwidth--and USB SSD have *much* better seek times than your USB HDD.

I'd probably want to do an experiment. Like grab a low cost but "good" USB SSD and try with one of your frequently used libraries on that. Again my starting point there would be a T5. But seem my later reply for more general comments. Even if you dont' end up using it for this, a T5 may be worth experiment with and then keeping as a transfer drive.

Quote:
Actually I don't really need a portable drive device. Does a Thunderbolt2 PCIe Box is really better than a SSD connected with an adaptor USBC->thunderbolt2, like the Samsung T5 ? (https://www.apple.com/fr/shop/produc...-thunderbolt-2)
I'm not following this question entirely. You linked to a Thunderbolt 3 to Thunderbolt 2 adapter. That's not relevant here, as although that is a bidirectional adapter, and could for example be used on your computer to connect to say Thunderbolt 3 audio interface, but unfortunately it cannot be used to connect Thunderbolt 3 PCIe/SSDs (like say a lovely Samsung X5) to your computer.

As I mentioned before, vendors like Sonnet Tech used to make Thunderbolt 2 PCIe SSDs. AFAIK they have all been discontinued and everybody is focused on Thunderbolt 3 SSD (none of which I am aware are backwards compatible). But what you can do is roll your own Thunderbolt to PCIe based system.. which is why I mentioned the Akitio PCIe expansion chassis, you can put a modern 4 x PCIe 3 lane SSD like a Samsung 970 Evo (~$400 for 2TB) in that (~$200) expansion chassis plus ~$20 for a PCIe slot to M.2 adapter card. The M.2 drive will run at PCIe 2 speeds and give you up to ~the performance of the internal drive... (but look at all the bandwith caveats below)... You may also be able to find other Thunderbolt 2 to PCIe expansion chassis still available, or maybe even find a Thunderbolt 2 to M.2 PCIe enclosure (be careful many of those are actually only USB). I'm not necessarily suggesting you do that, just explaining that option if you want the fastest possible externally connected SSD.

---

Thunderbolt 2 in principle sure is faster than USB 3, and the Thunderbolt 2 implementation on the Mac Pro is "better" than the USB 3 implementation. But to a point, and then is stuff still to know if you are pushing IO extremes (see below).

So the naive answer is a Thunderbolt 2 bus/chain can give up to 20 Gb/s (~2.5 GB/s) of IO, much faster that the ~500 MB/sec of USB 3/3.1 Gen 1.

(I know you know this, but I'll put it her for completeness). The first issue is lots of harm was done with folks who put SATA III SSD inside Thunderbolt enclosure of some sort ... then the SATA interface is the performance bottleneck and the drive basically delivers SATA III (i.e. ~USB 3) speeds anyhow, maybe just slightly faster, but nobody would notice. But in your case the question is would using something like that be better as it lets you avoid the trashcan's USB 3 bus bottleneck).

There are Thunderbolt drives that internally use PCIe (and more recently PCIe with NVMe) based SSD drives. There the simple view the is just a typical Thunderbolt 2 implementation takes 4 x PCie 2 lanes on the motherboard, turns them into Thunderbolt, and then inside the drive enclosure they are tuned back into 4 x PCIe 2 lanes (and can talk to a PCIe base SSD the same as if the PCIe SSD was plugged into a 4 x PCIe 2 slot in the computer.

That simple view gets more complex as you add more peripherals to the Thunderbolt bus, they all end up sharing the original bandwidth of those 4 x PCIe 2 lanes. And in the Trashcan you don't really have 6 separate Thunderbolt 2 busses. You have three busses, each connected to two ports. Again, this was a PCIe lane constrained design, bit its fairly standard for Thunderbolt to do this (e.g. my laptop has 4 Thunderbolt 3 ports, on two separate busses).

See details here https://www.techjunkie.com/mac-pro-t...lt-performance.

So you may want to make sure you connect high bandwith peripherals to ports on different busses

Another issue is Thunderbolt bandwidth is shared between PCIe/data and Thunderbolt display devices. Display devices have to share the same Thunderbolt cable bandwidth as the PCIe lanes, the controller chips at both ends multiplex/demultiplex these separate signals. I'm not aware of really good test measurements of the bandwith sharing, but a simple guess is to just subtract the raw display bandwidth from the total of 20 Gbit/sec upstream bandwidth in Thunderbolt 2. I would say avoid putting a 4K display on a Thunderbolt 2 connection that was also connected to super fast PCIe-based SSD drive(s). But not a problem say if connecting just a 500 MB/sec SATA SSD in a Thunderbolt dock/enclosure.

You mention having three SVGA displays. Did you really mean SVGA or HDMI? What resolution, refresh rate and color depth are those displays? ... with that you can guesstimate the bandwidth hit they might make. Only worry about that if they are high-resolution and you end up looking at PCIe based SSD connected by Thunderbolt.

---

I'll post later a more general suggestions for troubleshooting.

Last edited by Darryl Ramm; 09-18-2019 at 03:11 PM.
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  #10  
Old 09-18-2019, 05:40 PM
Darryl Ramm Darryl Ramm is online now
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Default Re: OWC dock data transfer rate

More comments on just debugging stuff. I do no use Kontakt, have played with it, and have helped solve issues on somebody else's system, but that is all. Others may have much better advice than me.

Quote:
Originally Posted by juh View Post
My sessions regularly bug (PT quits, or the cursor becomes spinning rainbow and I have to force quit). I don't really know the reason, but it mostly happens with sessions containing a lot of samples loaded in several instances of Kontakt, or with some virtual instruments using high CPU. So maybe it's a cache memory problem or other reason ... I really have no idea.
It seems fair to suspect disk performance is causing issues here, but I just want to make sure you don't miss something else. I expect you have already tried a lot of stuff, but I want to encourage you to take the tiem to have a clean go at troubleshooting stuff, even if you have tried that before. Starting with Trashing prefs (and doing so frequently as you try other stuff), making sure the system is fully optimized (go overboard: turn off bluetooth and networking etc at least for now, turn off Spotlight Indexing on all those HDD, etc.)

I would be turn off "ignore errors" if it happens to be on and see if Pro Tools throws any errors. That may give a clue.

How much memory is in your Trashcan? How large is your disk cache? That cache is only for timeline audio not samples but if you have it set too large and are using lots of VIs you may be running out of memory... a frequent cause of spinning beach balls and hanging type behavior. I would keep the Pro Tools CPU, memory and disk cache meters visible on the screen and see what they show when the system starts to misbehave. (and yes I'm normally not a fan of fixating on CPU meters, but just for now...). And a leading cause of memory exhaustion are memory leaks in plugins.... if you see Pro Tools memory usage keeping increasing you may have that... and you should make sure you are on all the latest compatible version of plugins installed.

I would sure go though updating all plugins. At some point (maybe after trying samples on an SSD if still stuck) and then try temporarily moving all .aaxplugin files from the plugin folder. Put them back in batches for just the VIs you want to use, leave all other plugins uninstalled, and see what happens.

Hopefully you have also able to use freezing and committing some tracks to reduce CPU load and overall startup time.

If Pro Tools hangs or quits with no Pro Tools error on the screen, then the logs in Console.app including in ~Library/Avid may give some clue what is going on. Look in System.log around that time as well for any other curious looking warnings or errors.

Quote:
My HD's sizes are 2x3To and 1x2To. I'd like to replace just one or two of them with SSD, and transferring my largest sample libraries on.
After some basic troubleshooting I'd be trying this as well. You have lots of choices...

Especially if I wanted to keep the Mac Pro for a while I'd be tempted to see if I could can get a 4TB internal SSD from OWC. But that's furtherest in the just nuke any problem out of existence category That internal drive will likely be usable for sessions or samples or both, and a fantastic test platform for playing with as it's easy to set up, and independent of anything else connected to USB or Thunderbolt. But it's probably expensive, these are custom drive made for OWC to work in the Trashcan, they are not standard M.2 drives, "thanks" Apple for that. These drives are in the ~2GB/sec range. The original price of that 4TB internal SSD from OWC was around $2k, but SSD costs have fallen a lot since then, I still expect it to be significantly more expensive that using say a Samsung 970 Evo in an external chassis (but they only go up to 2TB today). The available now in stock 2TB drive is ~$700. https://eshop.macsales.com/item/OWC/S3DAPT4MP20K/

One say T5 SSD (at a slower ~500MB/sec) should be OK on your USB3 ports, ... and usable for testing, and if you wanted to use more in future then you could get a Thunderbolt 2 to USB 3 hub/dock and connect several drives to that.

If you wanted to go high-end external then that PCIe expansion chassis and M.2 drive as mentioned in the last post. But that's clunkier and louder than the above options. The fan in the Akitio PCIe expansion chassis bugs some folks, and there are posts online about hacking them with a quieter fan).

You could also look at larger "RAID" style boxes for SATA SSD, but I'm just not that impressed by them and when looked at them in the details in the past, some suffer similar SATA bottlenecks as the dock that started this thread, and I never saw the benefit of investing lot into the associated metalwork/housing... but DAS and NAS boxes, especially with HDD absolutely have their places in larger studios, especially for archive/backup.


Quote:
The reason why I want to change is the loading time, which sometimes is really too long.
Kontakt has lots of possible optimizations, including using direct from disk to stream samples... (e.g. https://www.adsrsounds.com/kontakt-t...ze-kontakt-dfd) I'd probably spend some time just seeing if I could get that streaming to work reliably/shorten startup time. Certainly play around with that after switching to any SSD which should be able to stream much more than your HDD. Your other VI products may be similar.

Quote:
And I believe that my system would be more stable by freeing some USB ports (but maybe I'm wrong..). So I'd like to avoid using SSD drives with USB ports...
I'm not sure I'd say it quite that way... using the USB specifically won't make the system more or less stable... not with the current HDD you have... they are going to bottleneck well before the USB subsystem does. And I would sure be willing for example to do a quick test with say a T5 or other USB/SATA III based SSD drive connected to one port just to see.

Quote:
Concerning the money I could spend, I would say between 500€ and 1000€, depending on the gain of performance...
I think all the options above could fit into that price range for one or two drive, not all three (or four including audio/session?). The OWC 4GB SSD if still available might be at the top end.

Last edited by Darryl Ramm; 09-18-2019 at 07:04 PM.
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