Is the RPI SD card clocking speed established at startup?

Hi,

My RPI crashes after a while....

1. Is the SD card clock speed "discovered" by RPI at start up by it trying to find the fastest clock which works or is this speed fixed?

2. Does the working maximum clock rate for an SD card drop as it warms up?

3. I note that cooling the RPI SD card but not the RPI from a crashed RPI with freezer spray seems to make it much more likely the RPI will reboot successfully.

Thanks,

Nick

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wallarug over 13 years ago

Currently the SD card slot is not using the maximum spec of the SD card. There are people who have fixed this problem and are trying to get the foundation to incorporate the performance of the SD card into the next image.

See this: http://www.raspberrypi.org/phpBB3/viewtopic.php?p=91559 for more information.

I can not answer Q2 and Q3. Sorry.
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Former Member over 13 years ago in reply to wallarug

Fergus Byrne wrote:

Currently the SD card slot is not using the maximum spec of the SD card. There are people who have fixed this problem and are trying to get the foundation to incorporate the performance of the SD card into the next image.

See this: http://www.raspberrypi.org/phpBB3/viewtopic.php?p=91559 for more information.
As the instigator of that thread, I'll point out that most of the fixes are already incorporated in the current Raspbian image. In essence the driver now uses the maximum speed that the R-Pi hardware can support in combination with your card.
You're correct that this may not be the maximum the card can support, but this is largely due to the faster modes requiring the interface to run at 1.8v and the R-Pi only being capable of running the sd interface at 3.3v.

There's still work to be done - seems that some people are having data corruption problems. The latest changes to try to sort that have recently been pulled, see https://github.com/raspberrypi/linux/pull/70 but this may take some time to appear in a released image. In the meantime you may get the updates uring the 'rpi-update' command if it's in your chosen distro. If it's not, get it here https://github.com/Hexxeh/rpi-update
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Former Member over 13 years ago in reply to wallarug

Fergus Byrne wrote:

Currently the SD card slot is not using the maximum spec of the SD card. There are people who have fixed this problem and are trying to get the foundation to incorporate the performance of the SD card into the next image.

See this: http://www.raspberrypi.org/phpBB3/viewtopic.php?p=91559 for more information.
As the instigator of that thread, I'll point out that most of the fixes are already incorporated in the current Raspbian image. In essence the driver now uses the maximum speed that the R-Pi hardware can support in combination with your card.
You're correct that this may not be the maximum the card can support, but this is largely due to the faster modes requiring the interface to run at 1.8v and the R-Pi only being capable of running the sd interface at 3.3v.

There's still work to be done - seems that some people are having data corruption problems. The latest changes to try to sort that have recently been pulled, see https://github.com/raspberrypi/linux/pull/70 but this may take some time to appear in a released image. In the meantime you may get the updates uring the 'rpi-update' command if it's in your chosen distro. If it's not, get it here https://github.com/Hexxeh/rpi-update
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