SDHC card compatibility, Class 10/UHS I?


batfastad

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Hi everyone


Just wondering what capacities and speeds of SDHC cards the Pandora supports?


Is it worth me buying a Sandisk Extreme 32GB Class 10 UHS I?


Or is there a limit on what the Pandora actually supports?


Cheers, B
 
Pandora suports SDHC so there's no poblem with buying a 32Gb SD-Cad.


We don't support UHS cards so Class 10 is far enough.
 
Just wondering what capacities and speeds of SDHC cards the Pandora supports?
A theoretical max of 45MB/s. Practical transfer speeds have been benchmarked at 16MB/s read and 12MB/s writes.

Is it worth me buying a Sandisk Extreme 32GB Class 10 UHS I?
Depends on your use case. The class doesn't dictate average speeds, it simply gives a guaranteed minimum sustained write speed. A class 10 and a class 6 might both average 20MB/s write speeds, the key difference is that a Class 6 might drop to 6MB/s very briefly before getting back to full speed whereas the Class 10 will never drop below 10MB/s.


Assuming that's not the case, however, that the Class is tied to averages, a Class 2 can load a song in a second (or two), a class 4 is enough to playback a video about 40 times faster than normal. The aforementioned benchmarks were repeated with both class 10 and class 6, so unless you absolutely need to ensure your write speeds never drop below 10MB/s (such as recording raw HD video) there's no need to use a Class 10 over a Class 6, and you can probably even get away with Class 4.


Even if the averages are slower, as I said, all playback of whatever you're doing are well below the expected playback rate of whatever you're doing (Music, videos, PSX emulation, all have nominal requirements well below the 2MB/s gauranteed by Class 2). The only time a faster speed will offer benefit is if you're running the OS off an SD card (where faster loads is always a good thing) or when writing a lot of data to the card and waiting really isn't an option.

Or is there a limit on what the Pandora actually supports?
I seem to recall the only people who had any problems were those using exFat formatted cards, and one person who found their card to be just slightly too thin and needed to wedge it with a folded piece of paper. I could be wrong about that, but there's no practical reason other than these two (both of which are solvable) that any SD card wouldn't work.
 
Pandora suports SDHC so there's no poblem with buying a 32Gb SD-Cad.


We don't support UHS cards so Class 10 is far enough.

Clarifying that a bit - the Pandora is limited to about 17MB/sec on the card ports. UHS-I cards seem to work fine (for me anyway) so long as they are re-partitioned and re-formatted to something other than the proprietary Microsoft exFAT that they ship with.


No, the additional speed from a UHS-I card will not make a difference to the Pandora - it gets capped out.


I have used a Lexar 128GB 600X UHS-I card and a Lexar 128GB 400X UHS-I card in my Pandora without issues - once they're re-partitioned and re-formatted.


The UHS-I exFat formatted cards do not work, 'out of the box'.
 
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^


It was sorry, I had some wrong information then.


Didn't know that Pandora has such fast SD-Slots.


Thanks for clarifying.
 
Higher speeds than what the Pandora supports can also be useful if you're using the same card in other devices (which might achieve higher speeds). For instance if you have a music/movie collection on your brand new laptop which happens to support UHS SD, then it could be nice to have a fast card when you're copying over dozens of gigabytes worth of stuff.
 
then it could be nice to have a fast card when you're copying over dozens of gigabytes worth of stuff.
If waiting isn't an option. UHS class are significantly more costly than Class 4: some people don't have a problem paying that cost or have needs for more immediate feedback, and all power to them; personally I would rather save the money, start the copy, and do something else while it copies in the background, I usually have no problem waiting.
 
Thanks for the info.


So that's given me another question... what format do I need to re-format/re-partition a UHS card to?


Looking on Amazon just now there's 16GB Sandisk Ultra (30MB/s) Class 10 UHSI for £6.50... http://www.amazon.co.uk/SanDisk-Ultra-UHS-I-Class-Memory/dp/B007BJHETS/


I was thinking of going for a pair of those. God knows how I'll fill them up though.


Maybe I'll go with one of those and another MicroSD in an adaptor just so I can swap it in to a tablet/phone if needed.
 
I just use 32GB Sandisk SDHC cards and I am fine with them.


I have all my essential programming on one card, and it takes up about 16GB. The other card is reserved for all my Media...music, movies, etc.


The reason for this is because the second card can then be swapped for whatever media happens to be wanted at the time.


I copy all my music onto every Media card, so that, no matter what media card I'm using, my music will work. The movies are the only thing different on any SD card.
 
Anyone had any experiences with MicroSD cards in an adaptor?


Do they work with the Pandora?


Anyone know what sort of speed overhead the adaptor has?


Cheers, B
 
Yes, microSD works. The adapter is just wires connecting the pins, there is absolutely zero overhead as a result, a Class 6 micro card benchmarked at 20MB/s will behave exactly the same as a similar Class 6 regular size card with the same benchmarks.


The only difference is that the newest and fastest cards tend to only be available at regular sizes first, with microSD only coming out a year or so later for some reason.
 
I have a question along similar lines, would my 64GB UHS-1 microSDXC perform better in the SD slot or using a USB adaptor?
 
I don't think anyone has done any benchmarks, but according to Wikipedia "The theoretical maximum data rate in USB 2.0 is 480 Mbit/s (60 MB/s) per controller" so at least the theoretical limit is 33% higher. Wikipedia then goes on to say "Typical hi-speed USB hard drives can be written to at rates around 25–30 MB/s, and read from at rates of 30–42 MB/s" so about twice as fast as our SD speed. But ultimately the only way to know for sure is to try it.
 
In terms of power consumption, it's better to put it in the SD slot since you don't have the overhead of USB. Also for convencience you probably don't want to have a USB SD adapter plugged in all the time. In terms of speed, it depends on how fast the USB microSD reader is; in theory (like WizardStan said) it could be faster than the Pandora's SD slots.
 
Cool thanks, in terms of convenience I have a mini microSD reader which only sticks out 5-6 mm from the usb port.


How to test read/write speeds and power consumption on a pandora?


Also, is it possible to start up off USB?
 
I just bought a UHS1 microSD with reguler size adapter to test it on the Pandora. Fist used it to run Pandora OS from SD. It works pretty well, but not earth-shattering. Also tested transfer speeds on my PC. My regular SD cards read at about 11MB/s and write at about 9MB/s. The UHS1 card reads at about 14MB/s, but writes only around 8MB/s.


I have not sen any way to boot from USB.
 
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Looking for some larger SDXC cards and I'm wondering if anyone has tried any of these models on the Pandora?


7dayshop brand 64gb class 10 £27.99


http://www.7dayshop....d-64gb-class-10


(I currently use 2 x 32gb class 10 7dayshop cards without issue, so I reckon these should be okay aswell)


Kingston 128Gb class 10 £77.99


http://www.7dayshop....-128gb-class-10


(I'd like to try this one due to the low price but the SD compatibility list, shows smaller Gb Kingston cards have been a problem for some people http://pandorawiki.o...patibility_list so thats a bit worrying!)


Any advice/experience with these?
 
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