2 ms·

Yes USB3.0 is 500 MB/s but are you sure your bus is 3.0? It would imply your machine is 10+ years old. Most likely it's 3.1 or newer which is 1000 MB/s. And aga

by mrb 3y ago

Yes USB3.0 is 500 MB/s but are you sure your bus is 3.0? It would imply your machine is 10+ years old. Most likely it's 3.1 or newer which is 1000 MB/s. And again, benchmarking /dev/zero is invalid anyway as I explained (transparent compression)

doubled112 3y ago
TIL they have been sneaking versions of USB in while I haven't been paying attention. Even on hardware I own. Thanks for that.
crote 3y ago
No, it wouldn't imply the machine is 10+ years old. Even a state-of-the-art motherboard like the Gigabyte Z790 D AX (which became available in my country today) has more USB 3 gen1 (5Gbps) ports than gen2 (10Gbps). The 5Gbps ports are just marketed as "USB 3.1" instead of "USB 3.0" these days, because USB naming is confusing and the important part is the "gen x".
- mrb 3y ago
  I didn't mean 5 Gbps USB ports have disappeared, but rather: most machines in the last ~10 years (~8-9 years?) have some 10 Gbps ports. Therefore if he is plugging a fast SSD in a slow 5 Gbps port, my assumption was that he has no 10 Gbps port.
- Arnavion 3y ago
  To be clear for everyone: USB 3.0, USB 3.1 gen 1, and USB 3.2 gen 1x1 are all names for the same thing, the 5Gbps speed. USB 3.1 gen 2 and USB 3.2 gen 2x1 are both names for the same thing, the 10Gbps speed. USB 3.2 gen 2x2 is the 20Gbps speed. The 3.0 / 3.1 / 3.2 are the version number of the USB specification. The 3.0 version only defined the 5Gbps speed. The 3.1 version added a 10Gbps speed, called it gen 2, and renamed the previous 5Gbps speed to gen 1. The 3.2 version added a new 20Gbps speed, called it gen 2x2, and renamed the previous 5Gbps speed to gen 1x1 and the previous 10Gbps speed to gen 2x1. There's also a 3.2 gen 1x2 10Gbps speed but I've never seen it used. The 3.2 gen 1x1 is so ubiqitous that it's also referred to as just "3.2 gen 1". And none of this is to be confused with type A vs type C ports. 3.2 gen 1x1 and 3.2 gen 2x1 can be carried by type A ports, but not 3.2 gen 2x2. 3.2 gen 1x1 and 3.2 gen 2x1 and 3.2 gen 2x2 can all be carried by type C ports. Lastly, because 3.0 and 3.1 spec versions only introduced one new speed each and because 3.2 gen 2x2 is type C-only, it's possible that a port labeled "3.1" is 3.2 gen 1x1, a type A port labeled "3.2" is 3.2 gen2x1, and a type C port labeled "3.2" is 3.2 gen 2x2. But you will have to check the manual / actual negotiation at runtime to be sure.
  - crote 3y ago
    > There's also a 3.2 gen 1x2 10Gbps speed but I've never seen it used. It's not intended to be used by-design. Basically, it's a fallback for when a gen2x2 link fails to operate at 20Gbps speeds.

by mrb 3y ago

doubled112 3y ago

TIL they have been sneaking versions of USB in while I haven't been paying attention. Even on hardware I own. Thanks for that.

crote 3y ago

No, it wouldn't imply the machine is 10+ years old. Even a state-of-the-art motherboard like the Gigabyte Z790 D AX (which became available in my country today) has more USB 3 gen1 (5Gbps) ports than gen2 (10Gbps). The 5Gbps ports are just marketed as "USB 3.1" instead of "USB 3.0" these days, because USB naming is confusing and the important part is the "gen x".

mrb 3y ago
I didn't mean 5 Gbps USB ports have disappeared, but rather: most machines in the last ~10 years (~8-9 years?) have some 10 Gbps ports. Therefore if he is plugging a fast SSD in a slow 5 Gbps port, my assumption was that he has no 10 Gbps port.
Arnavion 3y ago
To be clear for everyone: USB 3.0, USB 3.1 gen 1, and USB 3.2 gen 1x1 are all names for the same thing, the 5Gbps speed. USB 3.1 gen 2 and USB 3.2 gen 2x1 are both names for the same thing, the 10Gbps speed. USB 3.2 gen 2x2 is the 20Gbps speed. The 3.0 / 3.1 / 3.2 are the version number of the USB specification. The 3.0 version only defined the 5Gbps speed. The 3.1 version added a 10Gbps speed, called it gen 2, and renamed the previous 5Gbps speed to gen 1. The 3.2 version added a new 20Gbps speed, called it gen 2x2, and renamed the previous 5Gbps speed to gen 1x1 and the previous 10Gbps speed to gen 2x1. There's also a 3.2 gen 1x2 10Gbps speed but I've never seen it used. The 3.2 gen 1x1 is so ubiqitous that it's also referred to as just "3.2 gen 1". And none of this is to be confused with type A vs type C ports. 3.2 gen 1x1 and 3.2 gen 2x1 can be carried by type A ports, but not 3.2 gen 2x2. 3.2 gen 1x1 and 3.2 gen 2x1 and 3.2 gen 2x2 can all be carried by type C ports. Lastly, because 3.0 and 3.1 spec versions only introduced one new speed each and because 3.2 gen 2x2 is type C-only, it's possible that a port labeled "3.1" is 3.2 gen 1x1, a type A port labeled "3.2" is 3.2 gen2x1, and a type C port labeled "3.2" is 3.2 gen 2x2. But you will have to check the manual / actual negotiation at runtime to be sure.
- crote 3y ago
  > There's also a 3.2 gen 1x2 10Gbps speed but I've never seen it used. It's not intended to be used by-design. Basically, it's a fallback for when a gen2x2 link fails to operate at 20Gbps speeds.