[NTLK] Storage card specifications

Andrei Chichak newton at chichak.ca
Wed Apr 6 11:18:04 EDT 2011

On 2011-April-05, at 9:35 PM, Bradley Loeding wrote:

> The theoretical value would be in the access time. Static RAM can be
> accessed at around 10-20ns, about 5-6 times as fast as flash, and the write
> time blows flash out of the water.

This doesn't quite cover it. Flash needs to be erased before its values can be changed. The erase operation is done on a page basis, typically 1/16 of the capacity of the chips and takes about 1 second per sector, thats about 8 orders of magnitude slower if an erase operation is necessary.

I suspect that the erase overhead is hidden by judicious double buffering, but it has to happen at some point.

More information about the NewtonTalk mailing list