Sujet : Re: Another security vulnerability
De : terje.mathisen (at) *nospam* tmsw.no (Terje Mathisen)
Groupes : comp.archDate : 11. Jun 2024, 10:39:50
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <v49617$102nd$1@dont-email.me>
References : 1 2 3 4 5 6 7 8 9 10 11 12 13
User-Agent : Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Firefox/91.0 SeaMonkey/2.53.18.2
Stephen Fuld wrote:
MitchAlsup1 wrote:
>
Do SSDs have their own cache ??
Usually, yes.
It has to have a substantial amount of RAM in order to coalesce writes, after applying all those remapping/wear leveling layers. This write-back cache has a limited amount of dirty buffers, preferably low enough that they can all be flushed to persistent storage in case of power loss.
Every single thumb drive produced (so not just SSDs) contain a little 32-bit CPU which does all that behind the curtain processing.
The main task however is that when first turned on, the CPU will run a substantial amount of burn-in testing, and then decide how many flash pages are actually usable. This way (according to "Bunny" Chang) every single flash chip manufactured is sold, be it at full or some much reduced capacity.
Terje
-- - <Terje.Mathisen at tmsw.no>"almost all programming can be viewed as an exercise in caching"