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I use a 64 GB Class 10+ microSD card with the computers' built-in card reader (sometimes requires a microSD to SD adapter), in place of a pen drive. This allows me to connect the card to devices without available USB ports.
Are microSD cards the same "under the hood" as a USB pen drive, or are there any advantages or disadvantages of using it compared to using a USB pen drive?
rahuldottech
Posted 2015-06-08T17:13:42.413
Reputation: 5 095
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Are microSD cards essentially the same inside the shell as a flash drive?
SD cards have their own communication standard and command set. A microcontroller in the SD card implements these, with possibly hackable firmware and vendor-specific commands.
A flash drive will implement the USB mass storage protocol in a microcontroller instead. These also have firmware that can be hacked/flashed/changed but aren't implementing the same standard as SD cards.
Both USB and SD cards have a similar internal overall architecture (not internal architecture - you can't hack a USB microcontroller to work as an SD card microcontroller, for example), but different external interface and different protocols.
There's no practical difference from an end-user standpoint other than:
On the hardware side ...
LawrenceC
Posted 2015-06-08T17:13:42.413
Reputation: 63 487
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Assuming you mean advantages over standard USB jump drives, there is no major dis/advantage seeing as how they are, more or less, the same technology. The only caveat is read/write speed. However, the same argument can be said for both.
Also assuming that you connect your Micro SD's using either a SD Card card adapter (computers) or Micro USB to Micro SD (tablets/phones), you can make sure that the cable/adapter/port are of the same speed class. See the following for more information: SD Card Speed Class
BiTinerary
Posted 2015-06-08T17:13:42.413
Reputation: 1 141
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Very few USB "flash-drives" have the feature on every standard SD card and microSD to SD holder: a READ ONLY switch. Whenever I use someone else's machine, I ALWAYS put the SD's mechanical switch into Read Only.
As for "speed" (and my USB-3 adapters to U3-Standard cards aren't "slow") security seems more important when I consider ... "BAD USB", which has NOT gone away. Many certified devices are vulnerable to this. How fast can YOUR USB "flash-drive" infect your network and compromise ALL your personal data? "Convenience is the opposite of security (and privacy)."
DrWattsOn
Posted 2015-06-08T17:13:42.413
Reputation: 49
Thank you fixer1234! Edited Nov 9. Any better now? – DrWattsOn – 2017-11-09T23:32:26.793
Note that those mechanical switches are strictly a suggestion; the controller ultimately decides whether or not the card can be written to. – Ignacio Vazquez-Abrams – 2017-11-09T23:39:42.727
@DrWattsOn, much better as far as the rant. However, I'm not familiar with the "bad USB" reference. Are you referring to the fact that larger form-factor pendrives can contain malevolent custom circuitry that isn't practical to hide in SD cards? That's true, but it isn't typically a problem with store-bought drives, which seems to be what the OP was referring to. The issue of infecting a system/network from a "certified" device (what is that?) being possible from a USB device but not a card isn't clear. Consider making the 2nd paragraph more explicit, maybe add a citation. – fixer1234 – 2017-11-10T01:52:00.753
2"This allows me to connect the card to devices without free or no USB ports" - How does the card reader connect to the devices? Anyway I don't see any disadvantages really except perhaps lower speeds and limited write cycles, but the same plagues USB sticks too (especially of the cheaper variety). – Karan – 2015-06-08T17:19:08.117
Basically, I can use it with a reader on most devices but a with an sd card adapter on others... – rahuldottech – 2015-06-08T17:28:31.320
Besides the fact micro sd cards were not design to be used as a flash drive and doing will reduce their lifespans? – Ramhound – 2015-06-08T17:29:58.357
1FWIW there are several SBCs (single board computers), e.g. Raspberry Pi & Wandboard, that employ a SDcard as its sole mass-storage R/W device. So whatever disadvantages there may be, it would seem that they were not significant enough to deter its use. Note that such SBCs access the SDcard through a MMC interface (rather than USB) which is a low-cost & simple interface (esp compared to USB or SATA). – sawdust – 2015-06-08T22:12:10.027