[Nook Color General] Blue6IX:
This is one of the things i'm trying to take a closer look at.

I was surprised to note that my class 10 card performed so poorly in testing. The packaging touted it as "for high performance and fast transfer speeds", essentially screaming it was class 10 sitting on the shelf.

At the time, that was exactly what I thought I needed, and i'm still glad to have it for testing. It's benched pretty decent so far for large file transfer, which is i'm sure what they had in mind behind the advertising and focus of the card.

I'm going to refrain from commenting just yet on the idea that they all have equivalent read speeds - but that is a good observational question to ask.

I need more test data to form an opinion. I put this thread up now because others can get real use out of the data i've collected so far.

Tentatively, with knowledge from the parent thread and this one i'll say:

- SanDisk class 2 or 4 in 4 or 8 gig capacity is the ideal MicroSD card for running an operating system on the Nook from the sdcard.

- Right now, knowing what specific cards are manufactured to the specs necessary for OS-level file operations between the device and the memory card are the only way to know what you need.

Using a class or size as a general "go get this" isn't good enough, you have to know what manufacturer makes the card that will do what you want, since different companies have different levels of quality expectation. SanDisk is our winner at the moment.

- Most memory card manufacturers don't focus on small block read/write. Probably due to the fact that unless you run operating systems or programs from the sdcard, it doesn't really matter.

A majority of the small digital electronics in the consumer market are digital/video cameras and mp3/media players. (that take MicroSD) E-book readers are still kind of niche devices, though that's changing fast.

The tablet market is basically a new thing just coming into it's own, and the mp3/media players benefit from the same specs as the cameras.

I think it'll be a little while before we start seeing memory cards optimized for small block read/write, but it's coming. This time next year a thread like this won't have the same level of importance as it does now, you'll probably be able to go by class rating to know what you need.

Right now the best we can do is try to figure out what cards/manufacturers have actually put effort into that aspect of data transfer in their memory cards.

The more we share our test results from the same program, the more we'll be able to go spend our money on what works, and not waste time and frustration fighting with the device we are trying to enjoy.

I'll be picking up a couple of things to test on wednesday, and I go on vacation on friday. Not sure if i'll have net access when I get there, but if not i'll have plenty of time to run a whole new set of tests and then play with the data.

I still have to pull my original benchmarks from the parent thread, and compare them to the new results. I have already seen some huge discrepancies without even looking.

Asking the kind of questions like you just did are precisely how we figure this out. Once the data is there, you can make whatever comparisons you want to it.