Looking for a fast external drive (for Mac Pro 6.1)

CFartist

macrumors newbie
Original poster
Feb 4, 2020
22
2
Hi,

I'm not tech-savvy, so please bear with me. I'm looking for a fast external drive to store my data and as a scratch disk for PS. Don't know if it should be TB2, USB3, etc. I also don't know if I should be looking for an SSD, flash blade, RAID, etc. I just want it to be around 1400mb/sec r/w or faster. Could you point me to the right direction please?

Cheers!
 

fhturner

macrumors 6502a
Nov 7, 2007
588
369
Birmingham, AL & Atlanta, GA
If you require that sort of speed, you're going to have to use Thunderbolt 2 on that machine, and it will have a "practical" limitation of around 1300-1400MB/s. So, I'm not sure of exactly which model to recommend, but I can say that the "or faster" part will likely not be possible (unless maybe you stripe a pair of them together). The Samsung T3/T5 USB3 drives are very good, in my experience, but they are USB3. Still, the ~500MB/s is quite fast...although if you absolutely have to have 1400MB/s, it obviously won't suit.
 

kohlson

macrumors 68020
Apr 23, 2010
2,328
689
USB3 interface will have a limit in the 500-ish MBs range, as noted above. USB-C can go significantly higher if they are equipped with an NVMe drive. See this video.

Your speeds will only be as fast as the slowest component.
 

fhturner

macrumors 6502a
Nov 7, 2007
588
369
Birmingham, AL & Atlanta, GA
USB-C can go significantly higher if they are equipped with an NVMe drive.
Actually, they won't. USB-C is a connector type, not a protocol or speed. He's on a 2013 Mac Pro, which is limited to USB3 speeds of 5Gbps, no matter the connector type.

Wait, hang on. I see this is no longer in the MacPro6,1 subforum...it has been moved since my first reply. @CFartist, are you indeed using a Mac Pro 2013? The answer to your question greatly depends on what system we're talking about...
 

tpivette89

macrumors 6502
Jan 1, 2018
486
250
Middletown, DE
It should be for a Mac Pro 6,1. For some reason, it got moved out of the Mac Pro forum, but it still applies to a 6,1.

TB2 would probably be the fastest speed. Some kind of TB3 enclosure mated to an Apple adapter to a TB cable would probably be the fastest solution.
 

CFartist

macrumors newbie
Original poster
Feb 4, 2020
22
2
I am using the Mac Pro 6.1. I noticed that the thread has been moved, so I edited the title.

From what I understand the PCIe bus of a MP 6.1 is limited to about 2 GB/sec.

late-2013-mac-pro-system-block-diagram.png


I'm happy with the speed being around 1300-1400 Mb\sec. But if I could get closer to that 2GB threshold, why not? Don't know if that's possible though.

I alluded to your question re model in the previous thread you started. The OWC 4M2 enclosure with some M.2 in a RAID 0 will saturate the TB2 port. May not be the cheapest solution though!
https://forums.macrumors.com/threads/upgrades-to-boost-ps-performance.2222286/
I am considering that option. I just wanted to know if I have other options, because it's not the cheapest solution indeed!
 

fhturner

macrumors 6502a
Nov 7, 2007
588
369
Birmingham, AL & Atlanta, GA
From what I understand the PCIe bus of a MP 6.1 is limited to about 2 GB/sec.

I'm happy with the speed being around 1300-1400 Mb\sec. But if I could get closer to that 2GB threshold, why not? Don't know if that's possible though.
It's not possible, at least via a single Thunderbolt 2 port. The PCIe bus is not itself limited to 2GB/sec, but what you're referring to is the link each Thunderbolt 2 bus (there are 3 in the Mac Pro 2013) has back to the CPU, which is PCIe 2.0 x4 (4-lane), so 500MB/s per lane x 4 lanes = 2GB/sec. HOWEVER, the part about the "practical" limitation that I mentioned comes into play: you're only going to see around 1350MB/s over any single TB2 port, due to whatever overhead is going on from PCIe switching, encapsulation via Thunderbolt, or anything else. Check this (and several other) BareFeats article about that:


Even though two 512G Samsung XP941s in a RAID 0 set are capable of an aggregate speed of 2231MB/s, the Magma ExpressBox 3T Thunderbolt 2.0 connected to a single Thunderbolt 2.0 port (single bus) topped out at 1346MB/s. We saw the same limitation when we connected one LaCie Little Big Disk Thunderbolt 2.0 (with dual XP941s) to one Thunderbolt 2.0 port.

So, the fastest you can go over a single port is 1350MB/s or so. Note that I keep saying "single port"...if you want faster, you can bridge 2 or 3 TB ports together, as Rob states further down his article. I'm not sure how practical that might be, though— you'll probably be needing to use some of that TB and DisplayPort bandwidth to hook up some displays. And unless you're just doing massive transfers all day long between the internal and external storage, I'm not sure you'd notice that 1350MB/s speed being that much of a hindrance. For your Photoshop scratch disk use case, I'm not sure whether or not that 1350 would be noticeably slower than, say, 3GB/s on some of the more recent NVMe PCIe 3.0 SSDs.
 

sam80

macrumors newbie
Jan 16, 2020
16
4
Speed test of OWC 4M2 where read's reaching the limit @fhturner mentions.

I was also thinking about striping multiple drives via 2 TB2 ports but never tried it. 7,1 arriving soon so no need for that for me, will repurpose the M.2 drives in an internal card.

Screen Shot 2018-08-02 at 15.37.57.png
 

CFartist

macrumors newbie
Original poster
Feb 4, 2020
22
2
Thanks for the replies guys! Around 1300mb/sec works for me.

Regarding OWC Express 4M2: I did some research and found that OWC gave each slot 1 PCIe lane. That means if I want to install only one blade, I'll get around 500 mb/sec. So, if I wanted speeds around 1300 mb/sec, I'd have to buy at least 2 blades in a RAID 0 or RAID 1(?). A bit pricey.

A member on the other thread mentioned this setup:

The Samsung X5 is attached and powered from the TB3 dock, which is attached to the Mac Pro using Apple's TB3 to TB2 adapter. Edit: I assume the speed is also around 1300 mb/sec.

Do I have other options at around £400 (~$500)? Been searching the internet for the past couple of days and I couldn't find anything else.

Also, how can I stripe multiple drives via 2 TB2 ports? Are these ports on the same bus or different?
 

fhturner

macrumors 6502a
Nov 7, 2007
588
369
Birmingham, AL & Atlanta, GA
Also, how can I stripe multiple drives via 2 TB2 ports? Are these ports on the same bus or different?
You can use Disk Utility to make a RAID 0 out of 2 or more disks. Here's how the busses are arranged:

 

sam80

macrumors newbie
Jan 16, 2020
16
4
Regarding OWC Express 4M2: I did some research and found that OWC gave each slot 1 PCIe lane. That means if I want to install only one blade, I'll get around 500 mb/sec. So, if I wanted speeds around 1300 mb/sec, I'd have to buy at least 2 blades in a RAID 0 or RAID 1(?). A bit pricey.
Yes, that's correct, it's more around 700 MB/sec for one blade. So you'll need 2 blades in a RAID 0. They probably don't have to be the fastest / most expensive M.2 due to this limitation.
 

Fishrrman

macrumors Core
Feb 20, 2009
19,418
6,722
You DO NOT WANT the Samsung X5 thunderbolt3 drive.

It WILL NOT WORK with a thunderbolt2 port, even with the tbolt2 to tbolt3 adapter.

I believe this has something to do with "power", and the adapter doesn't "pass" power to the connected device.

If I'm wrong, perhaps others will jump in and correct me.
 

CFartist

macrumors newbie
Original poster
Feb 4, 2020
22
2
Are there any compatibility issues between OWC 4M2 and Mac Pro 6.1?
Is it as simple as installing the blades and connect it to my MP (using Apple's adapter of course)?
 

sam80

macrumors newbie
Jan 16, 2020
16
4
Are there any compatibility issues between OWC 4M2 and Mac Pro 6.1?
Is it as simple as installing the blades and connect it to my MP (using Apple's adapter of course)?
All working happily for me for 1.5 years: Mac Pro 6,1 + Apple TB adapter + the enclosure. Never had any issues.
Yes, plus you need to create the RAID drive using software (I use Softraid, OWC's software that came with it).
 

CFartist

macrumors newbie
Original poster
Feb 4, 2020
22
2
You DO NOT WANT the Samsung X5 thunderbolt3 drive.

It WILL NOT WORK with a thunderbolt2 port, even with the tbolt2 to tbolt3 adapter.

I believe this has something to do with "power", and the adapter doesn't "pass" power to the connected device.

If I'm wrong, perhaps others will jump in and correct me.
Like I said, you'd have to connect the X5 to a TB3 dock and then connect the TB3 dock to the Mac using Apple's adapter.

All working happily for me for 1.5 years: Mac Pro 6,1 + Apple TB adapter + the enclosure. Never had any issues.
Yes, plus you need to create the RAID drive using software (I use Softraid, OWC's software that came with it).
Thank you for the fast reply sam80!
 

CFartist

macrumors newbie
Original poster
Feb 4, 2020
22
2
I was going to buy an OWC Express 4M2. However, after reading tons of reviews, articles and comparisons I changed my mind. I decided to pull the trigger and order an OWC Thunderblade 1TB. The price is almost the same as the 4M2 + the additional cost of 4 NVMe drives. Furthermore, the Thunderblade has 3 years warranty, compared to 1 year of the 4M2, and the design is better. Does anyone have it?
 
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