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A comment on Mistakes to Avoid When Buying a MicroSD Card (2018). Parent comment

Re:Mistakes to Avoid When Buying a MicroSD Card (2018) by stefan_ on Monday August 19, 2019 @10:43AM (#20738165)
The article mistakenly says "microSDXC slots" when it means "microSD" slot. Because SD, SDHC and SDXC all have the same physical form factor and slot you put them into, but vastly different electrical interfaces and protocols.

And yes, older versions like SD literally did not have the bits to even communicate cards with 512 GiB.

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Re:Mistakes to Avoid When Buying a MicroSD Card (2018) by makomk on Monday August 19, 2019 @11:19AM (#20738512)
SD, SDHC, and SDXC are all electrically the same (though newer cards can also optionally support higher-speed interface variants with different signalling voltages), it's just that the original SD protocol didn't have enough bits in the protocol to support higher capacities. SDHC and SDXC are basically the same except that one uses FAT32 and the other uses exFAT as its standard format. You can often use cards above the official 32GB limit in SDHC devices if you can format them as FAT32. A lot of older SD card slots can also be made to support SDHC with a suitable firmware or driver upgrade because the protocols are really similar, but with some fields just being interpreted slightly differently.
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Re:Mistakes to Avoid When Buying a MicroSD Card (2018) by muterad_murilax on Monday August 19, 2019 @10:52AM (#20738237)
> The article mistakenly says "microSDXC slots" when it means "microSD" slot.

No, I think it's correct. From Wikipedia [0]:

SDSC: 1 MiB to 2 GiB

SDHC: 2 GiB to 32 GiB

SDXC: 32 GiB to 2 TiB

SDUC: 2 TiB to 128 TiB

[0] https://en.m.wikipedia.org/wiki/SD_card

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Re:Mistakes to Avoid When Buying a MicroSD Card (2018) by stefan_ on Monday August 19, 2019 @10:56AM (#20738283)
Yes, all four of those as "micro" go into the same "slot".
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Re:Mistakes to Avoid When Buying a MicroSD Card (2018) by muterad_murilax on Monday August 19, 2019 @11:00AM (#20738322)
My point is that a "400 GB" card and a 512 GB card both are SDXC cards...
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Re:Mistakes to Avoid When Buying a MicroSD Card (2018) by wyldfire on Monday August 19, 2019 @11:19AM (#20738511)
But the reference is to a slot and not a card.
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Re:Mistakes to Avoid When Buying a MicroSD Card (2018) by muterad_murilax on Monday August 19, 2019 @12:15PM (#20739063)
So it's a microSDXC slot that doesn't support all microSDXC cards. Q.E.D.
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