[PeterT]

Try searching on "Small block writes".

For instance this post: (click on the blue symbol to see the original post with images).

Spoiler:

Originally Posted by DNSB

In the case of the Glo, that is what happened when I tried a factory reset.

When I was playing with the Glo, I found that selecting a uSD card with better small block writes made a very noticeable improvement in the speed of the device. Small block reads also seem to have a noticeable effect but the small block write speed is the one that varies horribly. I found that the SanDisk Class 4 cards gave me the best results.

Very often the Class 10 cards have done optimization for speed with large data blocks (writing 10MB on my digital camera). They seem to sacrifice small block speeds to obtain the better large block speeds.

I'm one of the people mentioning the lower class cards as being better in some circumstances. This originally came out of a Nook related discussion where some people found their Nook booted from an SD card performed well and others complaining this made their Nook run slower than molasses running uphill in Tuktoyaktuk in January.

I've attached 3 images from various Crystal DiskMark tests I ran on microSD cards (Lexar Class 10, Patriot Class 10 and a SanDisk Class 4 all 8GB) using the internal card reader on my laptop. In my digital and video cameras, the two Class 10 cards worked well. In my Glo, they made it noticeably slower. I suspect this is due to the small block writes where the Class 4 SanDisk was 65 to 171 times faster. The similarity of the sequential read speeds is, I suspect, a limitation of the Ricoh chip used for the card reader.

Regards,
David

Spoiler:

Originally Posted by DNSB

I'd suggest looking at a SanDisk class 4 uSD card instead. Do a search on small block writes for the reasons why. I posted some stuff in the memory upgrade with pictures thread in the Developer's Corner.

Regards,
David

Spoiler:

Originally Posted by DNSB

I played with the internal memory upgrade and have found that I needed to be selective with the SD card I used. I originally tried a Kingston class 10 16GB card but found that my Glo was noticeably slower than the original card.

So I had fun with testing various uSD cards and found the best one I had on hand was a Sandisk class 4 16GB card. Crystal DiskMark said it was much faster (1.81MB/s vs 0.019MB/s)* than the Kingston on small block random writes and 1.5x (3.1MB/s vs 2.03MB/s) faster on small block random reads. With that card, the Kobo is back to what seems to me to be the same speed as the original 2GB card.

* I ran the write test 4 times before I accepted the results. 95x was hard to believe.

Makes sense in a way since the original thread where I ran into the discussion of SD card speeds was installing CyanogenMod 7 on a Nook booting from the external SD card slot.

Regards,
David

Before you say it's just DNSB saying this, try searching via Google for people doing similar experiments on different devices.