[fedora-arm] 1ghz ARM Laptop (12in 1280x800 LCD)

[Nicolas Pitre]

On Wed, 2 Feb 2011, Gordan Bobic wrote:

> >  gordon is right about the SD/MMC card thing, but the "level 10" ones
> > can at least guarantee above 10mbytes/sec *read* capability.   so
> > _yes_ to the SATA interface.
> 
> The 10MB/s is _supposed_ to be for worst-case sequential writes. There 
> is, however, no defined benchmark, and manufacturers are free to do 
> their own testing. Most fail any sane real-world measurements of the 
> specification.
> 
> Just about every SD card I have seen apart from high end Lexar and 
> SanDisk manage a whopping 1-3 4KB write IOPS. Team Class 10 32GB SD card 
> is among those. So the class rating is pretty much completely 
> meaningless for anything except (at most) digital camera use where you 
> are sequentially writing large files to a FAT32 file system.

I'd suggest you have a look at the work being done by Arnd Bergmann on a 
new device mapper target to overcome typical SD card misbehavior:

https://wiki.linaro.org/WorkingGroups/KernelConsolidation/Projects/FlashDeviceMapper

This is based on a survey of card behavior analysis compiled here:

https://wiki.linaro.org/WorkingGroups/KernelConsolidation/Projects/FlashCardSurvey


Nicolas