__/ [ Aaron Gray ] on Thursday 02 March 2006 21:54 \__
>>> What are the step by step ... well, steps, to try out that thing that
>>> Window$ Vi$ta is going to have called "superfetch" where you use a USB
>>> device as extra Ram ... I know its a silly Window$ idea ... a USB device
>>> is waaaaaaay slower than Ram but I would like to see what's involved
>>> and if it makes any difference at all ... say with a 1gig USB memory
>>> Would it make any difference on Linspire/Linux ... I would like to know.
>> May make a good swap drive you could probably try it on Linux, if there
>> are Linux drivers for the USB device.
> Apparently there are problems with using a USB RAM Stick as a swap drive :-
> 1) USB stick flash memory does not like to be written very often. When
> written in the same location too much it will break. The manufacturere use
> a secial internal mechanism to recycle write locations in order to avoid
> this. However a swap disk usahe will most likely reduce its life span
> 2) The latency on the USB transactions is somehow big when compared
> with a HDD.
> 3) Also the internal architecture of the FLASH RAM is more suited for a few
> bigger reads/writes that many small writes and reads.
> Clued up and cut from alt.os.development :)
Intersting. That was my initial thought: latency. If it is not located on the
motherboard, then you essentially slow down the entire system until the USB
device becomes available and is able tom send large chunks of data back.
This which may be good under certain circumstances (e.g. storing images and
volumes), but not for programs that repeatedly swallow and spit out data to
USB storage as swap would be an intersting idea, provided it is quicker than
the hard-drive. I suspect it isn't so with SCSI interfaces and modern
storage devices, with proximity to the motherboard. Using USB would be
almost on par with using remote storage via Ethernet as virtual memory.
Silly yet deceiving 'selling point' for Windows Vista, I suppose.
Roy S. Schestowitz
http://Schestowitz.com | SuSE Linux | PGP-Key: 0x74572E8E
11:25am up 2 days 7:03, 8 users, load average: 0.62, 0.46, 0.45
http://iuron.com - next generation of search paradigms