16" M2 Pro Max - does it support USB 3.2. Gen 2x2?

[svenmany]

The tech specs say that the laptop supports USB4. But, from Wikipedia:

USB4 by itself does not provide any generic data transfer mechanism or device classes like USB 3.x, but serves mostly as a way to tunnel other protocols like USB 3.2, DisplayPort, and optionally PCIe.

The 13" M2 spec, https://support.apple.com/kb/SP870?locale=en_US, says it supports "USB 3.1 Gen 2 (up to 10Gb/s)". But, the 16" M2 spec, https://support.apple.com/kb/SP890?locale=en_US, is silent on that; all it says is USB4.

Does anyone know? I'm preparing to order an external SSD and I'd rather not spend more for USB 3.2 Gen 2x2 if it won't be utilized.

 

[dmccloud]

The tech specs say that the laptop supports USB4. But, from Wikipedia:



The 13" M2 spec, https://support.apple.com/kb/SP870?locale=en_US, says it supports "USB 3.1 Gen 2 (up to 10Gb/s)". But, the 16" M2 spec, https://support.apple.com/kb/SP890?locale=en_US, is silent on that; all it says is USB4.

Does anyone know? I'm preparing to order an external SSD and I'd rather not spend more for USB 3.2 Gen 2x2 if it won't be utilized.

By definition, USB specs are supposed to be backwards compatible. Looking at the most recent update to the USB 4.0 specification (from October 2022), I can't tell for sure what the status is of Gen 2 2x2, although Gen 2 in its initial spec is supported.

 

[svenmany]

By definition, USB specs are supposed to be backwards compatible. Looking at the most recent update to the USB 4.0 specification (from October 2022), I can't tell for sure what the status is of Gen 2 2x2, although Gen 2 in its initial spec is supported.

Thanks for that.

I've spent some time on https://en.wikipedia.org/wiki/USB4. There are a couple of charts. One chart says that USB 3.2 Gen 2x2 is a supported transfer mode. I might be misreading it somehow. Even if that mode is supported, it could be that the recent M2 Macs don't use that mode.

The M1 MacBook Pro's supported USB4, but they did not support the 2x2 mode. Which meant their USB speeds topped out at 10 Gb/s. The 2x2 mode tops out at 20 Gb/s.

I just got off the phone with a senior technical advisor at Apple. He is going to research this question for me via internal channels. He'll get back to me this coming Wednesday with the results.

 

[Chancha]

2x2 was an optional feature, and Apple refused to waste time implementing it, for better or worse. Some considers 2x2 a half measure only for temporary solutions.

And even though I haven't seen an explicit test, but seeing some speed test of generic type-C SSDs being plugged to M2 Macs I have not seen anyone reporting better than 10Gbps speed for the last weeks. So not a confirmation but that is that.

 

[svenmany]

2x2 was an optional feature, and Apple refused to waste time implementing it, for better or worse. Some considers 2x2 a half measure only for temporary solutions.

And even though I haven't seen an explicit test, but seeing some speed test of generic type-C SSDs being plugged to M2 Macs I have not seen anyone reporting better than 10Gbps speed for the last weeks. So not a confirmation but that is that.

Thanks for that info. I guess the full measure would be for me to buy a thunderbolt external SSD, but they are very expensive.

I was either going to buy a SanDisk Gen 2x2 drive or a slower SanDisk Gen 2 drive. For the second one, I'd only get 10 Gb/s, even if the mac supports 2x2. But, the first one would be a waste of the extra money if the mac doesn't support 2x2.

I'll certainly report it here if Apple gets back to me with more information.

 

[svenmany]

Got a call back from Apple support today. He doesn't know. The advisor put the question out to just one person and never got an answer. All the advisor was able to say was the it supports USB4 to 40 Gb/s.

USB4 supports various transfer mode. There's a great table of them at https://en.wikipedia.org/wiki/USB4. The Mac's 40 Gb/s is probably is USB4 Gen 3x2. And it might very well support 20 Gb/s, but it might do so with modes that don't match USB 3.2 Gen 2x2 specs (encoding and lane count).

I'm giving up waiting on an answer and going to make the assumption that 3.2 Gen 2x2 is not supported. I'm buying the cheaper drive.

 

[SpotOnT]

Supported or not Apple Silicon USB transfer speeds just aren't that great. Apple likes Thunderbolt, which works great....other than all the Thunderbolt devices out there are unreasonably expensive.

By definition, USB specs are supposed to be backwards compatible. Looking at the most recent update to the USB 4.0 specification (from October 2022), I can't tell for sure what the status is of Gen 2 2x2, although Gen 2 in its initial spec is supported.

I think 3.2 Gen 2×2 (20 Gbit/s) is optional in the USB 4 spec. Although 3.2 2x1 (10 Gbit/s) is supported.

 

[svenmany]

Supported or not Apple Silicon USB transfer speeds just aren't that great. Apple likes Thunderbolt, which works great....other than all the Thunderbolt devices out there are unreasonably expensive.

The cheapest way I found to get 40 Gb/s (signaling rate - data plus overhead) is by using an M.2 enclosure. I found one solution; the enclosure company advertises that, when paired with Samsung's 980 PRO SSD, it gets over 2500 MB/s. I priced it at around $290 for 2 TB. That's a bit expensive for me for my needs. I'll probably go that way one day for my "really active" files when my internal 2 TB drive's gets close to full.

 

[steve62388]

The cheapest way I found to get 40 Gb/s (signaling rate - data plus overhead) is by using an M.2 enclosure. I found one solution; the enclosure company advertises that, when paired with Samsung's 980 PRO SSD, it gets over 2500 MB/s. I priced it at around $290 for 2 TB. That's a bit expensive for me for my needs. I'll probably go that way one day for my "really active" files when my internal 2 TB drive's gets close to full.

Might want to update your firmware ASAP.

Samsung Issues Fix for Dying 980 Pro SSDs

Download the firmware fix ASAP if your 980 Pro is affected

www.tomshardware.com

 

[svenmany]

Might want to update your firmware ASAP.

Samsung Issues Fix for Dying 980 Pro SSDs

Download the firmware fix ASAP if your 980 Pro is affected

www.tomshardware.com

As it happens, I do have 980 Pro's in my Windows machine. I updated them this morning. Thanks for the heads up though.

 

[atonaldenim]

Does anyone know? I'm preparing to order an external SSD and I'd rather not spend more for USB 3.2 Gen 2x2 if it won't be utilized.

I just read a review of a Sandisk Gen 2x2 SSD that said it was able to get about 20Gbps speeds on a new M2 Max Macbook Pro. Searching for a second opinion to confirm the M2 Max now supports USB 3.2 Gen 2x2 lead me to this post, so I thought I'd let you know!

 

[svenmany]

I just read a review of a Sandisk Gen 2x2 SSD that said it was able to get about 20Gbps speeds on a new M2 Max Macbook Pro. Searching for a second opinion to confirm the M2 Max now supports USB 3.2 Gen 2x2 lead me to this post, so I thought I'd let you know!

Thanks so much for that information.

 

[atonaldenim]

Thanks so much for that information.

Before I spread too much disinformation, I specifically tested out a Sandisk Extreme PRO V2 1TB SSD at the Apple Store today, like the ones you asked about, and I found it got only 10Gbps USB speeds on M2, M2 Pro, and M2 Max computers.

I don't know what the difference is with the newer PRO-BLADE that let AppleInsider see 20Gbps speeds, while the older Extreme PRO doesn't seem to match it. But it seems that M2 doesn't necessarily have Gen 2x2 20Gbps support across the board.

Based on this test, I think your custom built USB4 enclosure idea is the best option right now for speed on a budget!

 

[hajime]

I just read a review of a Sandisk Gen 2x2 SSD that said it was able to get about 20Gbps speeds on a new M2 Max Macbook Pro. Searching for a second opinion to confirm the M2 Max now supports USB 3.2 Gen 2x2 lead me to this post, so I thought I'd let you know!

Why not M2 Pro Macbook Pro?

 

[svenmany]

Before I spread too much disinformation, I specifically tested out a Sandisk Extreme PRO V2 1TB SSD at the Apple Store today, like the ones you asked about, and I found it got only 10Gbps USB speeds on M2, M2 Pro, and M2 Max computers.

I don't know what the difference is with the newer PRO-BLADE that let AppleInsider see 20Gbps speeds, while the older Extreme PRO doesn't seem to match it. But it seems that M2 doesn't necessarily have Gen 2x2 20Gbps support across the board.

Based on this test, I think your custom built USB4 enclosure idea is the best option right now for speed on a budget!

Thanks again.

I've struggled to come to grips with USB4 and Thunderbolt. I've done a bit of reading, mainly Wikipedia and some of the USB4 spec (which I barely understand). But, I am most often confused by the casual and vague use of USB terminology in advertisements and conversation. Also, I wonder if some of the capabilities I've read about USB4 are ever found in mainstream products.

From what I've read, 20Gbps is achievable in USB4 in 3 different ways: USB 3.2 Gen 2x2, USB4 Gen 2x2, and USB4 Gen 3x1. The latter two are called "USB4 20Gbps". Is there any chance that the PRO-BLADE are actually hitting 20Gbps using USB4 20Gps?

Western Digital website is clear that the SanDisk Extreme PRO can use USB 3.2 Gen 2x2. But, they only say "USB-C (20Gbps)" for the PRO-BLADE. I downloaded the PRO-BLADE user manual. The picture there shows a port labeled "USB 20G". The picture for the PRO-BLADE Station shows 2 Thunderbolt 3 ports. It could be that the PRO-BLADE's are completely different beasts that the SanDisk Extreme PRO in terms of USB connectivity in that they support USB4 20 Gbps.

It's all clear as mud. USB4 version 2 was announced end of last year. I can just imagine seeing disks for sale on Amazon with "USB4 V2" in their description and customers having no idea what that means. At least I'll have the advantage of *knowing* that I have no idea what that means.

 

[SpotOnT]

USB really dropped the ball after 3.0 (5Gbps) and their labeling makes absolutely no sense now. This isn’t helped by the fact that most USB specs don’t have minimum real world requirements for the labeling, so manufacturers can call a lot of things whatever they want.

I am surprised there hasn’t been a stronger push for improved labeling and basic requirements. They just don’t seem to care.

 

[phrehdd]

USB really dropped the ball after 3.0 (5Gbps) and their labeling makes absolutely no sense now. This isn’t helped by the fact that most USB specs don’t have minimum real world requirements for the labeling, so manufacturers can call a lot of things whatever they want.

I am surprised there hasn’t been a stronger push for improved labeling and basic requirements. They just don’t seem to care.

Late response - agree. They should have a much simpler naming/code/speed list convention. I wouldn't have even minded USB 3.1 for 10, 3.2 for 20 and 3.4 for 40. Since a couple of these are already taken up, add zeros at the end to be specific 3.10, 3.20 and 4.00

 

[steve123]

I testing a Gen 2x2 enclosure today connected to a 16" MBP M2 Max and it only enumerated the port with a 10Gbps link speed.

 

[DRDR]

I testing a Gen 2x2 enclosure today connected to a 16" MBP M2 Max and it only enumerated the port with a 10Gbps link speed.

View attachment 2179876

I attached a Gen 2x2 NVMe enclosure to the OWC TB4 hub, connected to my M2 Mac mini. It shows up as USB 3.0 with 10 Gb/s. If a use a TB3 cable it achieves around 700 MB/s. If I use a not Thunderbolt certified cable it achieves around 400 or 500 MB/s. If I connect it to the TB3 daisy chain port of of TB3-device it also slows down, regardless of the used cable. So in summary: USB is still a mess, I will keep using TB3 enclosures.

 

[svenmany]

I attached a Gen 2x2 NVMe enclosure to the OWC TB4 hub, connected to my M2 Mac mini. It shows up as USB 3.0 with 10 Gb/s. If a use a TB3 cable it achieves around 700 MB/s. If I use a not Thunderbolt certified cable it achieves around 400 or 500 MB/s. If I connect it to the TB3 daisy chain port of of TB3-device it also slows down, regardless of the used cable. So in summary: USB is still a mess, I will keep using TB3 enclosures.

What do you get if you connect directly to the Mac, rather than through the hub?

 

[DRDR]

What do you get if you connect directly to the Mac, rather than through the hub?

Same speed as with the TB3 cable, but even when not using the TB3 cable. It is identified as USB 3.1.

 

[phrehdd]

Same speed as with the TB3 cable, but even when not using the TB3 cable. It is identified as USB 3.1.

I admit I am coming in rather later on all of this.
Bottlenecks -

• The enclosure itself
• The SSD within the enclosure
• the cable
• port connection on both sides of the cable

It might be wise to try another device that is known to have higher speeds or better yet, already measured on another system to be faster than the numbers you are getting now.

I have connected a Sabrent SSD directly to my system and got the expected numbers. I also put it on a hub using the same cable (provided) and get almost the same numbers. However, I had another SSD device that never got the numbers it was advertised as capable of, under any circumstances. My guess is there was somewhere in the device or cable a defect or misleading advertisement of the product. Last - yes, in some instances cables absolutely do make a difference contrary to the idea of either digital works or it does not.

 

[steve123]

I attached a Gen 2x2 NVMe enclosure to the OWC TB4 hub, connected to my M2 Mac mini. It shows up as USB 3.0 with 10 Gb/s. If a use a TB3 cable it achieves around 700 MB/s. If I use a not Thunderbolt certified cable it achieves around 400 or 500 MB/s. If I connect it to the TB3 daisy chain port of of TB3-device it also slows down, regardless of the used cable. So in summary: USB is still a mess, I will keep using TB3 enclosures.

macOS does not support USB 3.2 Gen 2x2. So, you can only connect at Gen 2 speed (10 Gbps). I am not certain if this is a hardware limitation or a driver issue.

 

[blamblam]

From what I have read on a reddit USB forum, it MAY be possible to get full speed on a USB 3.2 2x2 device with an M2 Mac with T4 ports. The trick seems to be you have to use an expensive "active" cable. I have not tried this. Has anyone out there done so?