[Discuss] Notebook Recommendations?

[richard.pieri at gmail.com (Rich Pieri)]

On 5/2/2016 11:31 AM, Kent Borg wrote:
> As reliable? Maybe, but the flash product the industry has most
> commonly put in consumer hands, SD cards, die left and right. (A
> quite new Samsung SD card instantly died on me just a few months
> ago.)

SD cards are to SSDs as floppies are to hard drives. Don't use one to
measure the other.

> Mechanical drives, being mechanical, frequently give warnings
> before completely dying. Flash? <poof!> And it's gone. Finally, I

I've had mechanical drives fail suddenly, without warning. On the other
hand, flash drives can provide warnings. Depends on the failure mode.

Media fails. This is why we do backups.

> have personally watched the underlying technology go from an admitted
> life span of 100,000s of writes (was it more, 15+ years ago?) down to
> I forget how few we are at now. Yes, I know about wear-leveling.

That 100K figure is not writes per block. It is writes per entire
device. As in a 1MB flash card can be written about 100K times before
all of the blocks are worn out. Given that each block in an old 1MB card
is 512 bytes that is about 2K writes per block or about 50GB total data
with perfect wear leveling. Without wear leveling, which was common to
Cisco routers for example, you could burn out a flash card very quickly.

Today's consumer MLC NAND is 2-3K writes per block or upwards of 50%
better than old style linear flash. With wear leveling and garbage
collection the write life of consumer MLC SSDs is literally petabytes of
data written. 3D NAND looks to improve wear life by 3-4 times due to
improvements in the manufacturing process which are necessary to make 3D
NAND.

> Finally, the higher levels of the software stack were built with
> disks in mind, flash doesn't necessarily swap in seamlessly. (See
> wear leveling.) I'm going flash, but warily.

Irrelevant on SSDs. The controllers on SSDs manage I/O distribution,
error correction, wear leveling, garbage collection, etc. Don't go by
the MMC/SD cards in tablets and phones which lack dedicated I/O controllers.

> Many are soldered. Removable is important to me when dealing with
> consumables. My Lenovo X230 had a few years left in it, until this
> unfortunate event. A bit of modularity helps in that.

Again, this is a tablet thing. Even Apple's SSDs in Macbooks aren't
soldered down except I believe the first generation Air.

-- 
Rich P.