Re: [9fans] just an idea (Splashtop like)

[erik quanstrom <quanstro@quanstro.net>]

> For the Intel SSD one must also consider:
>
> > 3.5.4 Write Endurance
> > 32 GB drive supports 1 petabyte of lifetime random writes and 64 GB drive supports 2 petabyte of lifetime random writes.
> That is equivalent to writing the capacity of the SSD 31250 times.  At
> the specified random 4K write rate of 3300 IOPS one could wear out the
> SSD in 876 days.  Non-random writes could cause more rapid wear,
> depending on their pattern and the wear leveling algorithms in the SSD.

do you think this is a serious limitation?  by my calculation, assuming
that you read everything written at least once and 10x faster read than
write leading to 3300 iops taking 1.1s
	1000^5 bytes /(3300 s^-1 * 1.1^-1 * 4*1024 bytes)/86400s/day
		= 942 days
this is 153 days short of the product lifetime.  by the way, one
would expect ~8 ures during this test (8e15 bits/1 ure/1e-15 bits).
(http://download.intel.com/support/ssdc/hpssd/sb/english_ssd_3_year_warranty.pdf)

do you really think its reasonable that someone could run this
drive at 100% of capacity for 2½ years?  even allowing for shipping
and installation time will get you pretty close to the warranty.
can you think of how this could be done with a plan 9 application
that's doing something useful?

it's hard to know if non-random writes create more wear than intel
specifies or not.  strictly sequential i/o should create similar wear
because 16 4k writes can be combined into one flash cycle and
16*3300*4k is about 216 mb/s.  so i don't see how you can get in
more flash cycles than 3300/s and increase the wear rate.

- erik