USB 3.0 card reader vs. USB 2.0 card reader ; worth it?

[CuriousMike]

Seems like everything I copy off my various memory cards hits the 15-20MB/sec rate.
I'm using a Sandisk Extreme card, rated at 30MB/s with a Sandisk Mobilemate USB 2.0 reader.


Has anyone else upgraded to a USB 3.0 card reader and noticed an appreciable difference in read speed... or am I simply limited to the read speed of the SD card?

[blastingcap]

USB 2.0 maxes out at about 35 MB/s so you will see no improvement unless you have a faster SDHC card in the first place

[CuriousMike]

My card is rated at 30MB/sec -- reading or writing ?

If it's reading, and USB 2.0 maxes out at 35... and I'm only seeing 15-20... then that tells me either
a) my card has a max read speed of 15-20
or
b) the reader, for whatever reason, maxes out at 15-20

The most likely answer appears to be the card is physically limited to 15-20MB/sec read speed.

[blastingcap]

*gets on soapbox* I only use Sandisk Extreme IIIs. Their ratings are for reading AND writing. None of that garbage where the write speed is slow... slow write speeds doesn't help with taking lots of photos in a burst. *gets off soapbox*

Read the fine print on your SDHC card; it could be 30 MB/s only on UHS-1. If you have a device that doesn't support UHS-1 (which is most devices made prior to 2012.. and even in 2012 there are some devices that don't support UHS-1), then I bet you your card has a lower rating when NOT using UHS-1, because there are few products out there that go all the way to 30 MB/s without using UHS-1.

I have a USB 3.0 reader that presumably can read UHS-1 and my 30 MB/s (with UHS-1 only) SanDisk Extreme III card gets 26 MB/s.

On a USB reader that can't read UHS-1, I would expect it to get about 19 MB/s, consistent with others' testing.

[Vdubchaos]

Unless you are doing LOTS of CONSTANT copying and making money while doing so......no it's not worth it.

[AkumaX]

I'm assuming you are using the SanDisk Extreme 45MB/s

In this case (and most UHS-I cards) you will see a very big difference on a USB 2.0 reader vs 3.0 Reader, even if you only have a USB 2.0 port

Yes, even though USB 2.0 maxes out @ 35MB/s, there is something fundamentally wrong with USB 2.0 card readers that have it so that it only maxes out @ 20MB/s

I will post examples soon! (out and about)

Here's the example, using the SanDisk Extreme 45MB/s.

If you can't see the image:

USB 2.0 port / USB 2.0 reader = 20MB/s read, 20MB/s write
USB 2.0 port / USB 3.0 reader = 36MB/s read, 30MB/s write
USB 3.0 port / USB 3.0 reader = 46MB/s read, 43MB/s write

[peonyu]

Personally I would buy a 3.0 card reader, sooner or later you will want one anyways. USB 2.0 is flaky above 20 MB/s most times as it is, there are alot of ways to chip at that "supposed" 35 MB/s and knock it down lower and lower from what I have seen. It could be the USB port is dirty, the cable is not to good etc. USB 3.0 has more than enough bandwidth to cover that up, and as far as the USB 3.0 card readers go right now, they are good quality so even on a USB 2.0 port you would likely see a increase in speed compared to a 2.0 card reader.

[AkumaX]

Originally Posted by CuriousMike

My card is rated at 30MB/sec -- reading or writing ?

If it's reading, and USB 2.0 maxes out at 35... and I'm only seeing 15-20... then that tells me either
a) my card has a max read speed of 15-20
or
b) the reader, for whatever reason, maxes out at 15-20

The most likely answer appears to be the card is physically limited to 15-20MB/sec read speed.

Do you have the SanDisk Ultra 30MB/s

I really really hate SanDisk for misleading customers like this.... they should definitely emphasize that the Ultra series' write speeds WILL BE LOWER!


32GB Extreme 45MB/s
32GB Ultra 30MB/s*write speed WILL be lower

In a USB 2.0 card reader (maxes out @ ~20MB/s)
======== Read |=| Write
Ultra ---- 20MB/s | 13MB/s
Extreme - 20MB/s | 20MB/s

In a USB 3.0 card reader, but in a USB 2.0 Port:
======== Read |=| Write
Ultra ---- 36MB/s | 13MB/s
Extreme - 36MB/s | 30MB/s

In a USB 3.0 card reader + USB 3.0 Port:
======== Read |=| Write
Ultra ---- 44MB/s | 13MB/s
Extreme - 46MB/s | 43MB/s

[shortylickens]

I got a USB 3 reader cuz it was cheap and I figured someday I'd need the speed. But today, no.
Also have a USB 3 hub, and again, really cant tell the difference.

[alkemyst]

Sandisk Extreme III have been superseded by the Sandisk Extreme now. Sandisk Extreme Pro is the current speed leader, but requires UHS-1 compatible devices to take advantage of that speed.