Mini Kobo Mini best Hack/Mod

[Quoth]

But how much time do you spend sending ebooks to the ereader rather than reading?

I agree it makes some difference and there are some old very slow 4G cards out there. I was suggesting that A2 not being available for 8, 16 or 32G cards wasn't an issue if it's a decent card anyway.

[DNSB]

Originally Posted by Quoth

But how much time do you spend sending ebooks to the ereader rather than reading?

I agree it makes some difference and there are some old very slow 4G cards out there. I was suggesting that A2 not being available for 8, 16 or 32G cards wasn't an issue if it's a decent card anyway.

Umm... the issue is not with sending books to the Kobo, the problem is with the normal operations of the Kobo where the underlying Linux OS uses a lot of small block read/writes. This discussion was beaten to death close to a decade ago and I lack any desire to re-fight that war. I've attached a DiskMark test on a local hard drive. The first 3 rows of numbers don't matter that much but the bottom row is, for my purposes, the important numbers. You will notice that in this case, the sequential read is about 100 times the random 4K block with queue width 1/single thread number. Testing a µSd card for a Kobo ereader, that last row has the most effect on the performance of the Kobo during reading.

[JSWolf]

Originally Posted by Cootey

From my searches, 32gb microSD cards don't come in A2. Only 64GB cards and up offered that. If they exist, I can't find them. Do you know where I can get an A2 32GB microSD card?

I haven't been able to find specs on the microSD card slot inside the Kobo mini. However, since the original 2GB microSD is formatted FAT32, not exFAT, the slot probably only supports SDHC with a maximum capacity of 32GB, just like FAT32.


Sent from my iPad using Tapatalk Pro

I didn't know a2 only started at 64GB. There's no A2 32GB.

What I suggest is that if you do have a spare 64GB microSDXC card, try that in the mini and if it works, get a Sandisk A2 64GB card.

[Cootey]

Originally Posted by DNSB

Actually, the speed of the card can be quite important to a Kobo ereader. Sadly, it is not the sequential write speed which the one most heavily advertised but the small block write speed that is critical. Over the years, I've found that Samsung and SanDisk cards tend to have the best small block write speeds.

To quote a message I wrote back in 2014:

Now that is very interesting. I have noticed that my Kobo Mini is considerably slower now with the 8 gigabyte microSD card. It's not unusable, but it is a Kingston card, and now I have a reason why it's so much slower. I'll make sure to pick up a SanDisk card when I upgrade to 32 GB.

These microSD cards aren't just for storage. They're the internal hard drives that hold the operating system. Slow performance will affect everything, which is why I became keen on card speed.

[Cootey]

Originally Posted by JSWolf

I didn't know a2 only started at 64GB. There's no A2 32GB.

What I suggest is that if you do have a spare 64GB microSDXC card, try that in the mini and if it works, get a Sandisk A2 64GB card.

I had two Sandisk A2 64GB microSD cards on hand. After using “dd” to clone the original 2GB card, I used Gparted to resize the partition (dd clones everything exactly—2 Linux and the FAT32 Kobo partitions, including their original partition sizes). I copied my Mini’s backup files onto the KOBOeReader partition, put it back into the SD card slot, then booted it up. Voilà!

It took a bit to boot, but it got there in the end, and I repaired my Kobo account to get rid of any corruptions.

It *is* faster than the 8GB Kingston microSD card that I had, but it’s not turbo charged. After all, it’s formatted FAT32, not exFAT, so it can’t take advantage of all the "new" speed enhancements. Still, though, it’s a nice hack for the Kobo Mini which originally shipped with just a 2GB drive. Things are snappy again AND I have plenty of room to grow.

Next I’ll stick more than 32GB of ebooks on it to see if things still work when storage exceeds the original 32GB microSD card limitation. It that works, I might consider a larger microSD card upgrade in the future. Thank you, everyone, for your input.

Update: I’ve used up over half of the storage now, and the Mini is still zippy and responsive. At this point, I would recommend upgrading your internal microSD card to a Sandisk A2 64GB microSDXC card. If I see a good sale on 128GB or higher SDXC cards in the future, I may play around with them and report back here.

[JSWolf]

@Cootey, your welcome. Happy to help.

[rpxcv]

1) So for sd upgrade what do you recommend? Sandisk and samsung? fat32 or exfat? A1 or A2? I would like at least 8 gb.

2) Since it has the same hardware as kobo glo (kobo4), is there any technical reason for blocking the official updates to 3.19.5761-s?
Has anyone else had problems with 4.35.20400? If so, which version do you recommend?

Thanks

[Cootey]

Originally Posted by rpxcv

1) So for sd upgrade what do you recommend? Sandisk and samsung? fat32 or exfat? A1 or A2? I would like at least 8 gb.

2) Since it has the same hardware as kobo glo (kobo4), is there any technical reason for blocking the official updates to 3.19.5761-s?
Has anyone else had problems with 4.35.20400? If so, which version do you recommend?

Thanks

I can answer the first part. I have had excellent results with Sandisk. As for the Mini’s microSD card format, it has to be Fat32. That’s the format the original microSD cards come in.

[rpxcv]

Originally Posted by Cootey

It *is* faster than the 8GB Kingston microSD card that I had, but it’s not turbo charged. After all, it’s formatted FAT32, not exFAT, so it can’t take advantage of all the "new" speed enhancements. Still, though, it’s a nice hack for the Kobo Mini which originally shipped with just a 2GB drive. Things are snappy again AND I have plenty of room to grow.

Is it faster because it is sandisk instead of kingstone or because it is sdxc A2 (exfat) format instead of sdhc (fat32)? Both?

I don't need a lot of memory however if a 64 gb sdxc A2 (formatted FAT32) improves performance significantly I might consider it.

[DNSB]

Originally Posted by rpxcv

Is it faster because it is sandisk instead of kingstone or because it is sdxc A2 (exfat) format instead of sdhc (fat32)? Both?

I don't need a lot of memory however if a 64 gb sdxc A2 (formatted FAT32) improves performance significantly I might consider it.

It is faster because SanDisk and Samsung both seem to care about small block read/write speeds so their µSD cards are pretty consistently the best in small block read/write speeds. The partition must be FAT32—minor correction, you can use ext4 if you use a Linux computer but that's a rather small segment of the market and it does require some tweaking.

If you want to see some results from a decade ago, check:

https://www.mobileread.com/forums/sh...2&postcount=17

https://www.mobileread.com/forums/sh...3&postcount=26

Oddly enough, the situation hasn't changed much over the decade. The sequential read/write speeds have improved but the small block results are definitely the red-headed stepchildren.

[rpxcv]

Originally Posted by DNSB

https://www.mobileread.com/forums/sh...3&postcount=26

Interesting. Here you were comparing a lexar/Patriot c10 to a sandisk c4. What about sandisk c10 vs sandisk c4 today? Has c4 still best performance in small block writes?

Could a 32 gb sandisk extreme microSDHC (Class 10, UHS-I, U3, V30) be a good solution today for my kobo mini or should I look for older microsd?

Originally Posted by rpxcv

2) Since it has the same hardware as kobo glo (kobo4), is there any technical reason for blocking the official updates to 3.19.5761-s?
Has anyone else had problems with 4.35.20400? If so, which version do you recommend?

Can anyone help here too?

[DNSB]

In my latest tests, SanDisk and Samsung are still the best choices for small block read/write performance. The last time I tested high speed µSD cards, the sequential read/write numbers were greatly improved but sadly the small block numbers were not any better than a decade ago.

Using that SanDisk card in your Mini would likely work quite well if you are looking for extra storage.

I've tested all the firmware releases up to the current 4.35.20400 on my Mini. The worst I've seen was some display oddities. OTOH, I've seen those on all my Kobo ereaders at one time or another.