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USB vs SD Card for Mac

Z

ZacT94

macrumors regular
Original poster
Jun 25, 2012
196
0
Hi everyone,

I'd like to ask you if I should get either a USB flash drive or SD Card for my MBPr. It's mainly for documents and music. I want to get 64 or 128GB and I am trying not to use up all my USB ports (one of the USB ports will be used by a USB modem).

Any help would be greatly appreciated.

Thanks everyone.
 
It depends. If you want transfers to be fast, get a USB thumb drive.

If you want something that doesn't stick out and doesn't use a USB port, I suggest getting a microSDXC card and a Nifty MiniDrive.

Note that any SD card will be way slower than a USB thumb drive, but for playing music and opening Office documents it shouldn't really make a difference. However if you want to make large transfers (GBs) of data at once the SD card is going to be really slow.
 
pgiguere1 said:
It depends. If you want transfers to be fast, get a USB thumb drive.

If you want something that doesn't stick out and doesn't use a USB port, I suggest getting a microSDXC card and a Nifty MiniDrive.

Note that any SD card will be way slower than a USB thumb drive, but for playing music and opening Office documents it shouldn't really make a difference. However if you want to make large transfers (GBs) of data at once the SD card is going to be really slow.
Click to expand...

But I've read that some SD cards like the 133x and 400x have much faster transfer speeds.
 
ZacT94 said:
But I've read that some SD cards like the 133x and 400x have much faster transfer speeds.
Click to expand...

I thought the same thing too ... please correct me if I am wrong ...

Also can you install Windows on the SD card? I might consider a 32 GB+ SD card and install my windows/bootcamp etc on it.
 
Ope said:
I thought the same thing too ... please correct me if I am wrong ...

Also can you install Windows on the SD card? I might consider a 32 GB+ SD card and install my windows/bootcamp etc on it.
Click to expand...

I am pretty sure that Windows can be installed on it, but I don't plan on using Windows on my Mac, even though this is my 1st Mac after growing up with Windows.
 
ZacT94 said:
I am pretty sure that Windows can be installed on it, but I don't plan on using Windows on my Mac, even though this is my 1st Mac after growing up with Windows.
Click to expand...

I understand what you mean being in essentially the same position.

I'm avoiding any use of Windows, however if I must use it I rather it not eat into my SSD.
 
It's not just the storage for me. I want to totally switch. What's the point of switching to a Mac if I use Windows on it? I take it that you have the base MBPr as well?
 
ZacT94 said:
But I've read that some SD cards like the 133x and 400x have much faster transfer speeds.
Click to expand...

133x is still nowhere near USB 2.0 speed. You must not confuse class ratings (Ex: Class 4, Class 10) with X ratings (Ex: 32x, 100x).

The class rating represents the maximum number of MB/s the card can transfer at, and the X rating is basically the same thing but divide it by 7 to get an approximation of the speed in MB/s.

For example, a 133x SDXC card will transfer at around 19 MB/s, while the theoretical maximum speed of USB 2.0 is 60 MB/s and USB 3.0 is 600 MB/s.

However you will not really get the max theoretical speed with any of those, a USB 2 drive will go at around 20 MB/s, a USB 3 one at around 60 MB/s and a 133x SDXC card at around 8 MB/s.

A 400x (UHS) SDXC is pretty fast though. You will get faster speeds than USB 2.0 but maybe not as fast as USB 3.0.

You could technically boot a virtual machine from any of those but expect it to be slow. As for an actual OS install I imagine it's doable but a little more complicated.
 
Last edited:
Aren't all the USB flash drives (the stick ones) USB 2.0 anyway?
 
Really? I obviously haven't been paying attention then because I didn't realise until so said so.
 
pgiguere1 said:
133x is still nowhere near USB 2.0 speed. You must not confuse class ratings (Ex: Class 4, Class 10) with X ratings (Ex: 32x, 100x).

The class rating represents the maximum number of MB/s the card can transfer at, and the X rating is basically the same thing but divide it by 7 to get an approximation of the speed in MB/s.

For example, a 133x SDXC card will transfer at around 19 MB/s, while the theoretical maximum speed of USB 2.0 is 60 MB/s and USB 3.0 is 600 MB/s.
Click to expand...

Class rating of SD cards represents the minimum speed they must run at. Class 10 card writes at 10MB/s at its slowest.
 
I use a 128gb SDXC 133 card, and you can find the review I wrote on this forum.

It's not very fast, yet for watching movies and using it as your download folder, it's enough.

I'd recommend a USB 3 drive if you need speed and storage, but if you need portability, a SD card is the way to go.
 
Does anyone know when a 128GB micro SDXC card will come out as I am looking at buying a Nifty Minidrive as it doesn't stick out of the slot.
 
Hrim said:
I use a 128gb SDXC 133 card, and you can find the review I wrote on this forum.

It's not very fast, yet for watching movies and using it as your download folder, it's enough.

I'd recommend a USB 3 drive if you need speed and storage, but if you need portability, a SD card is the way to go.
Click to expand...

I think I will likely do the same and use the SD card for storing tempory downloads, etc before sorting them. I don't keep videos and pictures on my laptop just music.
 
Different Macs deal with SD card differently

My Mid 2012 MBA SD card slot is connected to the USB port internally, so data max transfer rates are constrained by USB.

I don't know on the MBPr - if you do into system information, and look under SD card and USB, you will figure out which is on your system.

If it is under SD Card, it is a PCIe connection, so the interface will not be the speed constraint, but the card I/O rate will. SD cards in iMacs are this PCIe bus connected device.

The transfer rate is no better than the slowest link in the chain. A USB 3 stick is very fast, but if all you have is USB 2 in the computer, there is no benefit.
 
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