Surprised. Port 2.0 can actually transfer faster speed than you thought !?!

[novetan]

It was widely known that if the computer USB port is 2.0, the speed of transfer will be limited to 2.0 even if you plug in a flash drive 3.0. Correct? Wrong !

I accidently happened to realise its not the case. I was transfering a 5GB photo files from my 2017 iMac with 2.0 port to a 2.0 flash drive and took 30 mins. Then I inserted a 3.0 flash drive just to check whether it take the same time. But hell no. It just took 12 mins. Not believing, I repeated the experiment and achieve the same timing of 30m and 12m respectively. Then out of curiosity, I plugged in a HDD with micro B superspeed wire (which presumably faster than flash drive 3.0, I think), and took a mere 4m30s. I yet to experiment with a SSD. Maybe even faster. I like to know whats the reason against all established theory before I spend that extra money on SSD

 

[jaytv111]

2017 iMac actually has USB 3.0 ports. Actually every iMac is all 3.0 after 2012.

https://en.wikipedia.org/wiki/IMac_(Intel-based)#Slim_Unibody_(2012–2017)

You might have confused it with 2.0 because Apple doesn’t color USB ports based on speed (blue for 3.0) like most other manufacturers do.

 

[arw]

Besides the point @jaytv111 already made, your stated speeds/times do in no way indicate a USB 3.0 connection.

Did you mean iMac 2011?

Btw, just because a USB medium is 2.0 or 3.0 does not mean it necessarily reaches those speeds:
Your USB flash drives for example are just awfully slow in comparison (which is nothing unusual).
But even your HDD mentioned last seems surprisingly slow - and that is even if it was a USB 2.0 device:

- 5 GB in 4,5 min results in 18,5 MB/s which is not even close to the speed of USB 2.0 (~30 MB/s in real life).
- A quality USB 3.0 HDD can reach ~150 MB/s which would have transferred your 5 GB file in 33 seconds.
- Current USB SSDs max out the USB 3.0 connection at ~450 MB/s, resulting in a transfer time of 12 seconds for 5 GB - assuming the target/internal drive is capable of those speeds.

Or was the 5 GB file a typo?

 

[novetan]

Besides the point @jaytv111 already made, your stated speeds/times do in no way indicate a USB 3.0 connection.

Did you mean iMac 2011?

Btw, just because a USB medium is 2.0 or 3.0 does not mean it necessarily reaches those speeds:
Your USB flash drives for example are just awfully slow in comparison (which is nothing unusual).
But even your HDD mentioned last seems surprisingly slow - and that is even if it was a USB 2.0 device:

- 5 GB in 4,5 min results in 18,5 MB/s which is not even close to the speed of USB 2.0 (~30 MB/s in real life).
- A quality USB 3.0 HDD can reach ~150 MB/s which would have transferred your 5 GB file in 33 seconds.
- Current USB SSDs max out the USB 3.0 connection at ~450 MB/s, resulting in a transfer time of 12 seconds for 5 GB - assuming the target/internal drive is capable of those speeds.

Or was the 5 GB file a typo?

My bad. Tks for pointing out my typo error. Indeed it was 2011 model. 5GB photo is correct.

So question still remain why a 2.0 port can deliver faster speed when flash drive 3.0 was used over 2.0. Thought the “weakest link” will override

 

[arw]

Alright, it all makes sense now.

Yeah, it can be confusing:
Your Mac's USB 2.0 port is capable of ~30 MB/s.
Your USB 2.0 flash drive writes data at ~3 MB/s which is typical for lower end (cheap) USB 2.0 flash drives.
Your "USB 3.0" flash drive has a slightly better controller/chip and writes data with ~7 MB/s.
But those speeds are still so low/slow that the flash drive is not bottlenecked by the USB 2.0 port of the Mac.

So while technically the weakest link is indeed USB 2.0, your "USB 3.0" flash drive is even slower than that.
But as it is still faster than your even slower USB 2.0 flash drive, it may lead to wrong conclusions.

The marketing of flash drives can be very misleading. Just because they are USB 2.0 or 3.0 "compatible" does not mean they are capable of reaching the corresponding speeds. Especially the write speeds are often only a fraction of it - as you did experience.
You have to study the data sheet and pay good money for USB flash drives that actually deliver acceptable speeds.

In general, USB HDDs offer significantly better speeds.
In your case, a USB 2.0 HDD, a USB 3.0 HDD and even a USB 3.0 SSD should all offer the same ~30 MB/s as USB 2.0 is the "weakest link".

Edit: Btw, there have been Thunderbolt 1 adapters for your iMac that add a USB 3.0 port:

Buy Delock 62634 Thunderbolt / USB Adapter [1x Thunderbolt plug - 1x USB 3.2 1st Gen port A (USB 3.0)] Black 15.00 cm | Conrad Electronic

Top Delock Selection | Order easily now: Delock 62634 Thunderbolt / USB Adapter [1x Thunderbolt plug - 1x USB 3.2 1st Gen port A (USB 3.0)] Black 15.00 cm | Fast delivery | Reasonable prices

www.conrad.com

But they are hard to come by nowadays from retail stores.

 

[Nguyen Duc Hieu]

My bad. Tks for pointing out my typo error. Indeed it was 2011 model. 5GB photo is correct.

So question still remain why a 2.0 port can deliver faster speed when flash drive 3.0 was used over 2.0. Thought the “weakest link” will override

You are looking at and thinking of USB 2.0 vs USB 3.0.
But actually, the issue is the read-writing speed of each flash drive.
To really test the difference, try a 2.5" SATA SSD in different USB enclosure (2.0 vs 3.0) instead.
Then there will be no surprise at all.
End of discovery.

 

[novetan]

Alright, it all makes sense now.

Yeah, it can be confusing:
Your Mac's USB 2.0 port is capable of ~30 MB/s.
Your USB 2.0 flash drive writes data at ~3 MB/s which is typical for lower end (cheap) USB 2.0 flash drives.
Your "USB 3.0" flash drive has a slightly better controller/chip and writes data with ~7 MB/s.
But those speeds are still so low/slow that the flash drive is not bottlenecked by the USB 2.0 port of the Mac.

So while technically the weakest link is indeed USB 2.0, your "USB 3.0" flash drive is even slower than that.
But as it is still faster than your even slower USB 2.0 flash drive, it may lead to wrong conclusions.

The marketing of flash drives can be very misleading. Just because they are USB 2.0 or 3.0 "compatible" does not mean they are capable of reaching the corresponding speeds. Especially the write speeds are often only a fraction of it - as you did experience.
You have to study the data sheet and pay good money for USB flash drives that actually deliver acceptable speeds.

In general, USB HDDs offer significantly better speeds.
In your case, a USB 2.0 HDD, a USB 3.0 HDD and even a USB 3.0 SSD should all offer the same ~30 MB/s as USB 2.0 is the "weakest link".

Edit: Btw, there have been Thunderbolt 1 adapters for your iMac that add a USB 3.0 port:

Buy Delock 62634 Thunderbolt / USB Adapter [1x Thunderbolt plug - 1x USB 3.2 1st Gen port A (USB 3.0)] Black 15.00 cm | Conrad Electronic

Top Delock Selection | Order easily now: Delock 62634 Thunderbolt / USB Adapter [1x Thunderbolt plug - 1x USB 3.2 1st Gen port A (USB 3.0)] Black 15.00 cm | Fast delivery | Reasonable prices

www.conrad.com

But they are hard to come by nowadays from retail stores.

Tks so much for the detail explanation. Ok I got it. Indeed the 2.0 flash drive was more than 12 yrs old, the 3.0 maybe 8 yrs old. But I’d hv thought 2.0 means 2.0 and 3.0 means 3.0 however old unless the technology of chip etc changed, then it shld be called 2.1. Likewise for 3.0. Am sure something has changed for 3.0 so now become 3.1 and 3.2

 

[novetan]

Alright, it all makes sense now.

Yeah, it can be confusing:
Your Mac's USB 2.0 port is capable of ~30 MB/s.
Your USB 2.0 flash drive writes data at ~3 MB/s which is typical for lower end (cheap) USB 2.0 flash drives.
Your "USB 3.0" flash drive has a slightly better controller/chip and writes data with ~7 MB/s.
But those speeds are still so low/slow that the flash drive is not bottlenecked by the USB 2.0 port of the Mac.

So while technically the weakest link is indeed USB 2.0, your "USB 3.0" flash drive is even slower than that.
But as it is still faster than your even slower USB 2.0 flash drive, it may lead to wrong conclusions.

The marketing of flash drives can be very misleading. Just because they are USB 2.0 or 3.0 "compatible" does not mean they are capable of reaching the corresponding speeds. Especially the write speeds are often only a fraction of it - as you did experience.
You have to study the data sheet and pay good money for USB flash drives that actually deliver acceptable speeds.

In general, USB HDDs offer significantly better speeds.
In your case, a USB 2.0 HDD, a USB 3.0 HDD and even a USB 3.0 SSD should all offer the same ~30 MB/s as USB 2.0 is the "weakest link".

Edit: Btw, there have been Thunderbolt 1 adapters for your iMac that add a USB 3.0 port:

Buy Delock 62634 Thunderbolt / USB Adapter [1x Thunderbolt plug - 1x USB 3.2 1st Gen port A (USB 3.0)] Black 15.00 cm | Conrad Electronic

Top Delock Selection | Order easily now: Delock 62634 Thunderbolt / USB Adapter [1x Thunderbolt plug - 1x USB 3.2 1st Gen port A (USB 3.0)] Black 15.00 cm | Fast delivery | Reasonable prices

www.conrad.com

But they are hard to come by nowadays from retail stores.

Another question. Is there a 2.0 to 3.0 adaptor where I can insert to the 2.0 port and outcome the speed of 3.0? My guess is even there is such an adaptor the speed is still limited to 2.0 right?

 

[arw]

Another question. Is there a 2.0 to 3.0 adaptor where I can insert to the 2.0 port and outcome the speed of 3.0? My guess is even there is such an adaptor the speed is still limited to 2.0 right?

Unfortunately not. No adaptor can magically increase the bandwidth if the source port does not provide it.
That it why I mentioned the Thunderbolt 1 to USB 3.0 adaptor:
- The USB 2.0 port has a bandwidth of 480 Mbit/s
- Thunderbolt 1 offers 10 Gbit/s
- USB 3.0 is 5 Gbit/s
> So Thunderbolt can easily provide the speeds necessary for USB 3.0.

 

[tsialex]

Alright, it all makes sense now.

Yeah, it can be confusing:
Your Mac's USB 2.0 port is capable of ~30 MB/s.
Your USB 2.0 flash drive writes data at ~3 MB/s which is typical for lower end (cheap) USB 2.0 flash drives.
Your "USB 3.0" flash drive has a slightly better controller/chip and writes data with ~7 MB/s.
But those speeds are still so low/slow that the flash drive is not bottlenecked by the USB 2.0 port of the Mac.

So while technically the weakest link is indeed USB 2.0, your "USB 3.0" flash drive is even slower than that.
But as it is still faster than your even slower USB 2.0 flash drive, it may lead to wrong conclusions.

The marketing of flash drives can be very misleading. Just because they are USB 2.0 or 3.0 "compatible" does not mean they are capable of reaching the corresponding speeds. Especially the write speeds are often only a fraction of it - as you did experience.
You have to study the data sheet and pay good money for USB flash drives that actually deliver acceptable speeds.

In general, USB HDDs offer significantly better speeds.
In your case, a USB 2.0 HDD, a USB 3.0 HDD and even a USB 3.0 SSD should all offer the same ~30 MB/s as USB 2.0 is the "weakest link".

Edit: Btw, there have been Thunderbolt 1 adapters for your iMac that add a USB 3.0 port:

Buy Delock 62634 Thunderbolt / USB Adapter [1x Thunderbolt plug - 1x USB 3.2 1st Gen port A (USB 3.0)] Black 15.00 cm | Conrad Electronic

Top Delock Selection | Order easily now: Delock 62634 Thunderbolt / USB Adapter [1x Thunderbolt plug - 1x USB 3.2 1st Gen port A (USB 3.0)] Black 15.00 cm | Fast delivery | Reasonable prices

www.conrad.com

But they are hard to come by nowadays from retail stores.

There is also the write throttling factor that even drives with performant controllers/NAND combo have.

It's very difficult nowadays to find a drive that does not throttle down when you do too much writes. Each new generation of NAND is worse for that. Most drives on the entry level will overheat after writing some GB.

The omnipresent Kingston A400 is one of the best examples of that, you can overheat it to the point of throttling down to less than 5MB/s writes even when connected to a USB2.0 port while installing macOS or doing big backups.

 

[novetan]

Unfortunately not. No adaptor can magically increase the bandwidth if the source port does not provide it.
That it why I mentioned the Thunderbolt 1 to USB 3.0 adaptor:
- The USB 2.0 port has a bandwidth of 480 Mbit/s
- Thunderbolt 1 offers 10 Gbit/s
- USB 3.0 is 5 Gbit/s
> So Thunderbolt can easily provide the speeds necessary for USB 3.0.

Ok I guess it right.

Although 2.0 transfer speed is touted to be 480mb/s and 3.0 at 4.8 gb/s, I read in some google articles in reality it rarely get passed a quarter of that speed. In fact its even lucky to achieve a quarter of the advertised speed. Where's the choking point?

 

[novetan]

You are looking at and thinking of USB 2.0 vs USB 3.0.
But actually, the issue is the read-writing speed of each flash drive.
To really test the difference, try a 2.5" SATA SSD in different USB enclosure (2.0 vs 3.0) instead.
Then there will be no surprise at all.
End of discovery.

Good suggestion !

 

[jaytv111]

Use the Blackmagic Disk Speed test to find out how fast your drive is.
https://www.theverge.com/23294234/blackmagic-disk-speed-benchmark-how-to

Sometimes file copying is slower than it can be, the Blackmagic disk test tells you how fast it is under ideal conditions.

I've used this and seen my 3.0 SSDs go up to 400 MB/s (3.2 Gb/s).

 

[joevt]

Ok I guess it right.

Although 2.0 transfer speed is touted to be 480mb/s and 3.0 at 4.8 gb/s, I read in some google articles in reality it rarely get passed a quarter of that speed. In fact its even lucky to achieve a quarter of the advertised speed. Where's the choking point?

USB 3.0 must be less than 4 Gbps since it uses 8b/10b encoding. A SATA III 6g SSD should be able to achieve max USB 3.0 speed ≈450 MB/s. A SATA III SSD can get slightly over 500 MB/s in a USB 3.1 gen 2 enclosure.

You can connect a Thunderbolt 3 device (with two Thunderbolt 3 ports) and connect a USB 3.1 gen 2 enclosure to get near USB 10 Gbps speed (< 9.7 Gbps since USB 3.1 gen 2 uses 128b/132b encoding) ≈1000 MB/s but less than that for a Thunderbolt 1 Mac.