Aura H2O Firmware on MicroSD?

[ProDigit]

I've heard that the H2O has an SD card inside as main memory.
Not sure if that info was correct though...
SD cards tend to go corrupt a lot faster than flash memory.

In case my device breaks down/bricks, is there a way to upload Kobo firmware on another (micro)SD card and insert it in the device?
Or have I understood it completely wrong, on the memory issue?

[GeoffR]

Originally Posted by ProDigit

I've heard that the H2O has an SD card inside as main memory.
Not sure if that info was correct though...

That is correct.

SD cards tend to go corrupt a lot faster than flash memory.

Not true. SD card storage IS flash memory, just mounted on a removable card. So if you are not inserting and removing it frequently then the service life should be the same as other flash memory.

In case my device breaks down/bricks, is there a way to upload Kobo firmware on another (micro)SD card and insert it in the device?

Yes you can do this. This is one of the main benefits of having the internal storage on a removable card. Another one is that you can ugrade to a larger card by copying the old card to the new one and expanding the user partition to fill the extra space.

[ProDigit]

SD, and MicroSD cards are much more prone to wear than regular flash memory, which has a controller built in.
I've ran operating systems from SD cards, and they usually go bad after a good month to 4 months.

USB memory sticks last lots longer for some reason. The memory on SD cards has lower EEC, AND usually is pressed on a print board, while USB memory sticks have the memory built in their own chip, with controller and everything.
Running an operating system from USB memory sticks usually lasts a good year to two years.


Concerning copying the old card info to a new one,
Is it regular copying, or are there any boot flags that need to be set?

[meeera]

Originally Posted by ProDigit

SD, and MicroSD cards are much more prone to wear than regular flash memory, which has a controller built in.
I've ran operating systems from SD cards, and they usually go bad after a good month to 4 months.

I've run a number of Kobos for years, and not one has "gone bad". Nor is "usually go bad within months" the norm here, at all.

[GeoffR]

Originally Posted by ProDigit

SD, and MicroSD cards are much more prone to wear than regular flash memory, which has a controller built in.
I've ran operating systems from SD cards, and they usually go bad after a good month to 4 months.

So you expect Kobo ereaders will only last 1-4 months too? Kobo would have gone broke long ago if that was true, as most of them (all the current ones except the Aura) have their operating system on removable micro-SD cards.

Of course if you buy poor quality or counterfeit cards then they will fail sooner, but there is no reason to expect that a good quality micro-SD card will fail within 10 years if it is not being frequently inserted and removed. [EDIT: 10+ year typical lifespan according to SD Association]

Concerning copying the old card info to a new one,
Is it regular copying, or are there any boot flags that need to be set?

You need to copy the raw image, not just the filesystem. In Linux you'd use the dd command. [EDIT: There is a thread describing the process in detail: Memory Upgrade Mod Guide (With Pictures), but for the H2O there is the added complication that you would need to re-seal it afterwards it you want it to remain waterproof.]

[ProDigit]

I'm not saying 4 months. I was running Windows and Ubuntu on these memory devices, which have significantly more writes than the small mobile OS of Kobo.

When SD cards go bad, they could have bad flash memory sector (which indeed takes years to turn bad). If it's one sector, that's located where an ebook is placed, you can delete, and re-download the book, so no harm done there.
If the bad sector is on a boot sector, that's another story.

There's also the possibility of a bad sector caused by a software error; which if any boot or operating system file is being written while the error occurs, could lead to a buggy or failing device.
Software errors could happen because of a variety of problems, and are probably the leading cause of buggy programs (next to buggy programming).

[GeoffR]

Originally Posted by ProDigit

I'm not saying 4 months. I was running Windows and Ubuntu on these memory devices, which have significantly more writes than the small mobile OS of Kobo.

When SD cards go bad, they could have bad flash memory sector (which indeed takes years to turn bad). If it's one sector, that's located where an ebook is placed, you can delete, and re-download the book, so no harm done there.
If the bad sector is on a boot sector, that's another story.

There's also the possibility of a bad sector caused by a software error; which if any boot or operating system file is being written while the error occurs, could lead to a buggy or failing device.
Software errors could happen because of a variety of problems, and are probably the leading cause of buggy programs (next to buggy programming).

All that applies to other flash memory too, not just micro-SD cards. The only fundamental difference between removable cards and other flash memory is that removable cards can fail as a result of physical wear when being inserted and removed, but that is not a problem when used as internal storage because they are usually only inserted once and not removed until they are to be replaced.

Micro-SD cards have their own firmware that includes error correction, wear balancing, fault management etc. so a single bad sector is not usually fatal, it just gets marked as bad and another one used instead, same as on a hard disc or other storage. The device firmware doesn't need to know anything about this, it is handled by the firmware on the SD card itself.

[ProDigit]

Originally Posted by GeoffR

All that applies to other flash memory too, not just micro-SD cards. The only fundamental difference between removable cards and other flash memory is that removable cards can fail as a result of physical wear when being inserted and removed, but that is not a problem when used as internal storage because they are usually only inserted once and not removed until they are to be replaced.

Micro-SD cards have their own firmware that includes error correction, wear balancing, fault management etc. so a single bad sector is not usually fatal, it just gets marked as bad and another one used instead, same as on a hard disc or other storage. The device firmware doesn't need to know anything about this, it is handled by the firmware on the SD card itself.

From my understanding, SD cards (and micro SD cards) do not have the controller on their cards. The controller is on the SD card reader.
USB FLash drives, have them on the chip.

Most of the errors on an SD card happens when 2 interactions at the same time happen (like a read and write, or 2 writes). That's one of the reasons that on many phones you can only do one transaction at a time, and when you're copying a large file from or to your phone, you will not be able to do other actions on the phone memory, like renaming, moving, copying, or deleting files or folders, while you can from a USB drive.

At least, that's my understanding of it.

[GeoffR]

Originally Posted by ProDigit

From my understanding, SD cards (and micro SD cards) do not have the controller on their cards. The controller is on the SD card reader.
USB FLash drives, have them on the chip.

Micro-SD cards have their own onboard microcontroller too, just like non-removable flash memory chipsets, USB sticks, etc. See this article for some of the gory details.

There are some very poor quality micro-SD cards available for sale, and naturally if you buy one of them you can expect all sorts of problems. But exactly the same applies to non-removable flash memory.

[frostschutz]

I don't care if the card breaks, I can just replace it, but so far it hasn't been a problem. While there have been some users in these forums who stated their card went bad, I would not worry too much about it.

[ProDigit]

Sd cards aren't as fast as flash chips either.
Their average 4k IOs are very low.
If this device had the memory of a flash drive, it would boot at least 2x to 3x faster.

[frostschutz]

The card that came with my H2O was actually quite fast, a lot faster than the cheap sandisk cards I had at home.

I'm not sure why you are whining about cards. Even if they had only half the lifetime and half the speed of a soldered chip, I'd still choose the card. Having an unbrickable device is a huge bonus.

[meeera]

Originally Posted by frostschutz

The card that came with my H2O was actually quite fast, a lot faster than the cheap sandisk cards I had at home.

I'm not sure why you are whining about cards. Even if they had only half the lifetime and half the speed of a soldered chip, I'd still choose the card. Having an unbrickable device is a huge bonus.

Definitely. I'm supremely unbothered by boot time, as I only ever turn my device off when troubleshooting.

[GeoffR]

Originally Posted by ProDigit

Sd cards aren't as fast as flash chips either.
Their average 4k IOs are very low.
If this device had the memory of a flash drive, it would boot at least 2x to 3x faster.

I'm not sure exactly what you mean by a flash drive*, but it would be very easy to test whether having internal storage on a micro-SD card rather than non-removable flash memory chips (which is what the thread was about to begin with) has a significant effect on boot speed: The Kobo Aura has the latter while other devices of the same vintage (Glo, AuraHD) have the former, so if someone has one of each (with the same setup) then they could time how long they take to boot.

Do you think the Aura would be 2x-3x faster than the Glo or AuraHD?

* If you mean a SSD drive then you might well be right, not sure how you could test it though. Some of us have tried replacing the micro-SD cards in our Kobos with faster ones, I think the general result is that it has some minor effect on things like boot speed, time to open large books for the first time, and a larger effect on the time to transfer large files (or many files) from computer to device via USB, etc. but not on anything important to what most people use their ereaders for, reading ebooks.

[DNSB]

Originally Posted by ProDigit

Sd cards aren't as fast as flash chips either.
Their average 4k IOs are very low.
If this device had the memory of a flash drive, it would boot at least 2x to 3x faster.

Just for the heck of it, I compared two Kobo Touch ereaders. One (N905C) has a removeable uSD card for internal storage, the other (N905) has non-removable flash memory. Using a pinhole reset to restart the ereader and a stopwatch to record the time from releasing the reset switch to the home screen appearing, the boot time was virtually identical for both devices.