-------- Original-Nachricht -------- > Datum: Thu, 13 Jan 2011 10:17:20 +0100 > Von: "Miha Vrhovnik" <miha.vrhov...@cordia.si> > An: dovecot@dovecot.org > Betreff: Re: [Dovecot] SSD drives are really fast running Dovecot
> >"As a sanity check - I found some data from Mtron (one of the few SSD > oems who > >do quote endurance in a way that non specialists can understand). In the > data > >sheet for their 32G product - which incidentally has 5 million cycles > write > >endurance - they quote the write endurance for the disk as "greater than > 85 > >years assuming 100G / day erase/write cycles" - which involves > overwriting the > >disk 3 times a day." > > > >That was written in 2007. SSD flash cell life has increased > substantially in > >the 3-4 year period since. > Stan you are wrong on that... > flash cell life decreases when they shrink process in which they are made. > > With the new generation of 25nm flash it's down to 3000/programming > cycles. So the drive manufactures have to battle that with increasing a ECC > length and better wear leaving. Or if I quote anand > "When I first started reviewing SSDs IMFT was shipping 50nm MLC NAND rated > at 10,000 program/erase cycles per cell. As I mentioned in a recent SSD > article, the move to 3xnm cut that endurance rating in half. Current NAND > shipping in SSDs can only last half as long, or approximately 5,000 > program/erase cycles per cell. Things aren’t looking any better for 25nm. > Although > the first 25nm MLC test parts could only manage 1,000 P/E cycles, today > 25nm MLC NAND is good for around 3,000 program/erase cycles per cell. > > The reduction in P/E cycles is directly related to the physics of > shrinking these NAND cells; the smaller they get, the faster they deteriorate > with > each write." > I would not use MLC in a server environment. SLC has much better program/erase cycles per cell. > Please read the article on annandtech [1] > > 1 - > http://www.anandtech.com/show/4043/micron-announces-clearnand-25nm-with-ecc > > Regards, > Miha -- NEU: FreePhone - kostenlos mobil telefonieren und surfen! Jetzt informieren: http://www.gmx.net/de/go/freephone
