What's important in a memory card upgrade

[Derf]

So, I know that the standard 8GB in the Clara HD can hold thousands of books. Which is quite a few thousand more than I currently own/have.

However, if I were so inclined, what would I look for in a memory card to make the loading/reading of ebooks faster?

I see lots of benchmarks on micro SD cards, and they have basically 6 categories : sequential read, sequential write, 512K read, 512K write, and 4k read, and 4K write.

The small 4K read/write are always slower than sequential read/write. And I wonder, with a ePub that is maybe half a MB, would the 4K read/write be an important factor?

And does anyone know if the hardware in the Kobo devices will be limiting to take advantage of a $50 top-speed card?

[DNSB]

Originally Posted by Derf

So, I know that the standard 8GB in the Clara HD can hold thousands of books. Which is quite a few thousand more than I currently own/have.

However, if I were so inclined, what would I look for in a memory card to make the loading/reading of ebooks faster?

I see lots of benchmarks on micro SD cards, and they have basically 6 categories : sequential read, sequential write, 512K read, 512K write, and 4k read, and 4K write.

The small 4K read/write are always slower than sequential read/write. And I wonder, with a ePub that is maybe half a MB, would the 4K read/write be an important factor?

And does anyone know if the hardware in the Kobo devices will be limiting to take advantage of a $50 top-speed card?

The sequential read/write and 512K read/write seem to have little influence on the performance of Kobo ereaders where I have upgraded the internal card. the 4K read/writes seem to have much more effect. The large block performance numbers make a difference on videos and photos where you are dealing with multi-megabyte files. The average ereader filesize is much smaller.

Also remember that part of the card is used by the operating system and Linux and it's descendants are very fond of reading and writing small blocks.

[ilovejedd]

Originally Posted by Derf

So, I know that the standard 8GB in the Clara HD can hold thousands of books. Which is quite a few thousand more than I currently own/have.

However, if I were so inclined, what would I look for in a memory card to make the loading/reading of ebooks faster?

I see lots of benchmarks on micro SD cards, and they have basically 6 categories : sequential read, sequential write, 512K read, 512K write, and 4k read, and 4K write.

The small 4K read/write are always slower than sequential read/write. And I wonder, with a ePub that is maybe half a MB, would the 4K read/write be an important factor?

And does anyone know if the hardware in the Kobo devices will be limiting to take advantage of a $50 top-speed card?

4K read/write. You want one with at least 1MB/s. With cards that have slow 4K, you might experience OS hanging/stalling.

Yes, the internal card reader is slow. Something like the Samsung EVO should do quite nicely. No need to get the PRO.

[Derf]

Thanks,
I decided to try a Samsung EVO Plus 32GB. It actually has pretty speedy 4K read/write speeds. I'm thinking of making the upgrade more for the operating system, returning search results, sideloading transfer speeds, opening books, etc, rather than the sheer number of books stored.

In case anyone wants to look at some reviews of cards, I found one site with a nice comparison.
https://www.cameramemoryspeed.com/re...icro-sd-cards/

And here is the site that gave me info on the Samsung Evo Plus.
https://www.jeffgeerling.com/blog/20...omparison-2018

[Atilla]

Does not have to be an expensive one. My 32gig Sandisk class 10 (old model solid black)
reads 9.2 and writes 1.7 with CrystalDiskMark 6 (4kb) tests.

[frostschutz]

dunno about the clara hd, but my aura h2o came with a very fast card out of the box

it was faster than any other cards I had at home at the time

pretty much all cards you can buy today, should be fast enough for ebook readers. it won't change some things being slow...

a lot of operations will run from ram (cache) anyway, the devices have plenty of ram (for ebook reader) which is rarely ever actually used.

[ilovejedd]

Originally Posted by frostschutz

pretty much all cards you can buy today, should be fast enough for ebook readers. it won't change some things being slow...

a lot of operations will run from ram (cache) anyway, the devices have plenty of ram (for ebook reader) which is rarely ever actually used.

There are cards that may do fast sequential (necessary for high resolution photos or videos) but still have abysmal 4K performance. Like way below HDD level: 0.05MB/s or less. The good ones tend to perform at HDD level as far as small block goes.

Granted, I can be a bit exacting as I need my cards to deal well with apps and full Linux OS (well, Raspberry Pi and before that, Nook Color and Android devices). You may be right that even 0.05MB/s suffices for the Kobo. After previous experience with constant crashing though, I wouldn't take a chance on a card/flash drive that needs to run an OS when the price difference is usually just a couple of bucks.

[DNSB]

Originally Posted by frostschutz

pretty much all cards you can buy today, should be fast enough for ebook readers. it won't change some things being slow...

a lot of operations will run from ram (cache) anyway, the devices have plenty of ram (for ebook reader) which is rarely ever actually used.

The last time I did some testing during February, I found that there are still quite a few SD cards that have totally abysmal small block read/write performance. And I can and do notice the effect on my ereaders, Raspberry Pi and 3-D printer when using those cards -- the blasted 3-D printer is slow enough without timeout errors reading from the SD card. Basically, Samsung and SanDisk are still the two manufacturers with consistent small block performance.

[Incanus]

Originally Posted by DNSB

The last time I did some testing during February, I found that there are still quite a few SD cards that have totally abysmal small block read/write performance.

As of now (December 26th, 2018) has anyone got a better recomendation for the Clara SD card replacement (read speedwise) other than the 32Gb Samsung EVO (Plus)?

What about 64Gb cards? It's Samsung EVO (Plus) the best / easier to find alternative or is another one recomended (read speedwise) for Clara SD card replacement?

Awaiting your kind reply,

[INCANUS]

[ilovejedd]

The Samsung Pros are faster but it's not worth the price premium. I doubt the card reader on the Clara can do UHS, in the first place.

Any of the Samsung EVOs at whatever capacity you require is a good choice. Just make sure you buy a genuine card. Plenty of counterfeits on ebay and even from Amazon Marketplace sellers.

[Incanus]

Originally Posted by ilovejedd

The Samsung Pros are faster but it's not worth the price premium. I doubt the card reader on the Clara can do UHS, in the first place.

Duly noted.

Originally Posted by ilovejedd

Any of the Samsung EVOs at whatever capacity you require is a good choice. Just make sure you buy a genuine card. Plenty of counterfeits on ebay and even from Amazon Marketplace sellers.

A prompt and clear response: good advice.

EDIT: If you have any input on a related question, I'd be much obliged to read it.

Gratefully yours,

[INCANUS]

[ilovejedd]

Originally Posted by Incanus

EDIT: If you have any input on a related question, I'd be much obliged to read it.

Alas, can't help you on that one. Reason I upgrade my storage is for manga (~100-200MB per 200 page volume). Even if I fill up the 64GB card, I've still only got less than a thousand books on my e-reader.

[Incanus]

Originally Posted by ilovejedd

Alas, can't help you on that one. Reason I upgrade my storage is for manga (~100-200MB per 200 page volume). Even if I fill up the 64GB card, I've still only got less than a thousand books on my e-reader.

Fair enough.

Again, thankyou for your prompt reply.

Best regards,

[INCANUS]

[Stridr]

Is this also possible on the Kobo Forma?

[HarryT]

Originally Posted by Stridr

Is this also possible on the Kobo Forma?

No. It doesn’t contain an SD card.