pi 3 max sd size

hello,

max size for pi 3 B plus is 32Gbite or 64Gbite ? And the speed ? It's convenable use SD UHS II or III ?

Regards

Reply to
Mirko
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64GB certainly works. I've not used a larger SD card as I move to using a USB3 memory stick or SSD for better reliability.

Prior to the Pi 4B the SD card interface is quite slow, so UHS-I is more than sufficient.

So I would just go with a Samsung or SanDisk 64GB UHS-I. Smaller sizes don't tend to be any cheaper now, and I'm not finding class 4 or 6 cards have any better random access speeds than a good UHS-I these days.

---druck

Reply to
druck

I haven't tried it but I don't believe there is a size limit, at least up to the 2TB of the SD standard. You'll have to reformat >32GiB cards to not be ExFAT - writing an image with dd or Etcher (rather than installing via NOOBS) will do that.

Look for IOPS or 4K random write benchmarks for a card. That's generally the performance bottleneck for running an OS on it, rather than raw MB/s.

Theo

Reply to
Theo

My old RPi2 recently refused updates using the old default 100MB FAT32 partition and a 4GB EXT4 partition (on a 4GB Sandisk SD card so I transferred both partitions to a new 16 GB SD card:

- used gparted, on a laptop running Fedora Linux 32, to create a 1GB FAT32 partition and a 15GB EXT4 partition. This step could also be done on an RPi using cfdisk

- Downbloaded the latest ISO image for Clonezilla (2.7.0) from

formatting link
and burnt it to a CD.

- Used clonezilla to copy both partitions from the old SD card to the new one.

- swapped SD cards in the RPi and it booted immediately from the new card.

This should work just fine if you're running Windows on your PC because the Clonezilla CD is a complete, bootable Debian system. Partition the new SD card on the RPi if your Windows partitioning tool doesn't understand Linux disk formats and then populate the new card using Clonezilla.

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Reply to
Martin Gregorie

See here:

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"If you're planning to use a card of 64GB or more with NOOBS, see this page first.

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Note: Because of a constraint in versions of SoC's used in the Raspberry Pi Zero, 1 and 2, the SD card partition size limit is 256GB. From the Raspberry Pi 3 onwards this limitation does not apply."

With speed, it's a case of how fast do you need it? But they note that the "class" ratings aren't an exact measure for general usage.

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Reply to
Computer Nerd Kev

sdxc_formatting.md

not only are they not an exact measure some manufactures either do not know what they mean or simply lie (I have seed cards claiming class 10 but then in the specifications quoting transfer rates that were barely class 2!)

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Reply to
alister

On Thu, 03 Dec 2020 21:59:13 GMT, alister declaimed the following:

One: all the SD card ratings assume one of the FAT file systems is in use. That means no journaling of file changes to the media.

Two: Class-10 rating is based on streaming a SINGLE file (video) on freshly formatted card -- absolutely no file fragmentation. Class-2/4/6 is based upon multiple small files (still image photos) on a possibly fragmented (if one has deleted some photos but not all) card.

Three: Card makers support differing numbers of "open allocation units". The cheaper Class-10 cards may only have two open AUs -- one holds the FAT and the other buffers the single file data. Better cards may support up to 6 open AUs. Since flash memory requires a full erase (to all

1 bits) and then can write 0-bits to the block, but can not convert a 0-bit back to a 1-bit without doing the entire block, every time the card has to jump to a different block it has to perform an erase and merge of "old" data from a different block, before writing new data into the block. Having 6 AUs allows the card to keep some blocks open for random I/O access without committing them to the flash memory and running an erase cycle. This really helps for journaling file systems, since any write ends up with changes to at least three blocks -- write data , write meta-information to journal, sometime later commit journal to actual file system meta-data. On a 2 AU card, every toggle from write data (presume, say, a log file that gets a new line every so often) to update journal would trigger an erase operation on the card.
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Reply to
Dennis Lee Bieber

is in

on

yes but the card I refereed to not only tested as slow transfer rates the makers small print also quoted the same (class2) data rates. the class 10 branding on the card was blatantly false.

The obscure/cheap brands are simply not to be trusted

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Reply to
alister

The bigger concern with cheap cards is often whether they even deliver the advertised capacity. Consider this:

formatting link

$16 for 1 TB? You can't even get spinning rust that cheap. If it sounds too good to be true, that's because it is.

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$230 for 1 TB is closer to what you'd expect, with 512-GB options ranging from $65 to $100. (It's also SanDisk, instead of a company you've never heard of.)

_/_ / v \ Scott Alfter (remove the obvious to send mail) (IIGS(

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Top-posting! \_^_/ >What's the most annoying thing on Usenet?

Reply to
Scott Alfter

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