Re: Bad microSD
 

I am still waiting for Patriot Memory to get back to me about my RMA, but unfortunately, it seems like I will be stuck with this useless microSD.
Has anyone had any luck getting it to work?

Re: Bad microSD
 

I have exactly the same problem with Transcend 8GB Class 6 card and Adata 16GB class 10 card. They work and test just fine on multiple PCs in multiple card readers, but in N900 they are bad news.

So far the only one that works reliably for me is Sandisk 16GB class 2, but it is extremely slow (as the class 2 rating would indicate).

It's really disappointing and I've spent a lot of money on SD cards.

I suspect maybe the N900 isn't providing enough voltage to the SD card and some cards are less tolerant of low-voltage situations than others. Does anyone know if it's possible to tell what voltage or change the voltage of the SD card in N900?

Re: Bad microSD
 

Here's an example of formatting with badblocks check on a ~2GB partition on my Adata card:

Re: Bad microSD
 

It's not really a class 10 problem, as much as it's a Patriot Transcend Adata problem. I consider these to be very poor companies to buy from, and will only usually do so if a specific card has stunning reviews and also has a good price, otherwise it's usually not worth it. In the case of Transcend and Patriot 32GB class 10, the reviews on Newegg and Amazon are very awefull, I didn't even look at Adata as I have had way to much bad luck with them. Many of the reviews have bad problems getting them to work with Android devices.

I have a 32GB, class 10, Lexar, which I just made an ext2 partition and transfered the Easy Debian Image to the file system, and used it without any errors whatsoever. The performance of this card is really good.

Sandisk is usually very conservative with their class ratings, and most of my Sandisk class 2 cards perform easily within class 4 specs or even higher. The one exception is the 32GB class 2 Sandisk, while it does performs within the class 2 spec, strangely it's read speed is very very poor compared to other Sandisks, which are usually quite high. It's write speeds are actually very good, but strangely average read speed are actually lower than average write speeds, which is pretty bizarre, but max read speeds are higher than max write speeds, but not by much. It's OK performance, but some people have complained about stuttering when playing back video on it on Android devices, I haven't had this problem on the n900.

There was briefly a Sandisk 32GB class 4 microsd, on the market, but I couldn't find it anymore, this one might perform really well.

Re: Bad microSD
 

New kernel patches seem to alleviate this issue.
Please see http://talk.maemo.org/showthread.php?p=1000405 for details.