No surprise on memory
wad at laptop.org
Thu Dec 18 10:52:19 EST 2008
The soldered in NAND is also 14 times slower on writes and half
the speed of a good SD card.
On Dec 18, 2008, at 5:51 AM, John Gilmore wrote:
>> What about using a NAND partition as swap? Has this ever been done?
>> Given that partition support is a recent development it seems
> Swapping to the soldered-in NAND chips is a very bad idea. It will
> tend to wear them out rapidly. Even if you use load-leveling software
> (e.g. swapping to a file in a jfffs2 filesystem), the problem is that
> if you do start wearing out serious numbers of flash blocks, the
> laptop becomes toast; it requires a soldering iron and spare chips to
> fix it.
> A much more reliable scheme would be to swap to an SD card, if one is
> plugged in and contains a swap partition (or a file in its root called
> SWAPFILE). See http://dev.laptop.org/ticket/8410. Even a small,
> cheap SD card could double or triple the available virtual RAM space.
> And if an SD card gets worn out, you merely pull it out of the laptop,
> throw it away, and buy a new one (for a fraction of the original cost,
> since Moore's Law has been working in your favor in the intervening
> This doesn't solve the least-common-denominator problem of people
> SD cards -- but it does offer a user, or a deployment, a very
> simple and
> relatively cheap way to solve most problems related to physical RAM
> On the topic of memory overload in general:
> Older XO releases did much better things when they ran out of physical
> memory: they tended to rapidly kill off some process, leaving the
> largely functional. In 767, the system instead goes from usable to
> molasses-like in a period of seconds, then freezes totally for minutes
> or hours. As far as I know, nobody has debugged why that changed.
> prior behavior was infinitely preferable.
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