----- Ursprüngliche Mail ----- > Von: "Christian Loehle" <CLoehle@xxxxxxxxxxxxxx> > Your eMMC likely treats the boot partitions differently than the user area, e.g. > in regards to cache. > Is this reproducible for more 4k writes? What about larger writes? Yes. So far every write size I tried is slow. Sometimes (1 out of 50) small writes are fast, that's most likely a caching effect of eMMC internals. > The eMMC might not even have the mapping available after boot and first has to > internally switch to it, in contrast to at u-boot stage? Wouldn't that explain only the first slow write? I see poor write speed also on repeated runs. > Anyway this is probably more a question to your eMMC manufacturer and nothing > the host is to be blamed, as you mentioned yourself, the time is spent at > CMD25. The eMMC manufacturer says there is nothing special about the boot area and write speed should be equally fast. Can it be that rcar-gen3-sdhi changes some timings after switching? Either in software or on hardware. Thanks, //richard