On Tue, Jan 27, 2015 at 08:20:36AM -0800, Yasha Karant wrote:
> There are hybrid disk drives that have a "small" SSD flash memory
> along with the regular spinning media, typically to serve as a cache
> for lower latency.  Does anyone have long term experience with these
> units?  Most flash memory is not designed for the long term repeated
> read/write/erase cycles of a primary disk drive -- how are these
> holding up?  Is the flash configuration totally transparent to the
> Linux file systems and formatting operations?
> 

This type of device is not useful for DAQ applications:

- for bulk data storage (4TB and bigger), the SSD cache is not useful,
- for OS, everything fits on a normal SSD,
- for user home directory, maybe useful, but the standard computer
  already has 1 SSD (OS) and 2 HDD (raid1 mirrored for bulk data storage),
  adding 2 more hybrid HDDs just for user home dir makes no sense (would
  make it 5 devices grand total).

Also I notice that all hybrid HDDs listed at newegg.ca have only 8GB of SSD,
this is very small, one is better off adding 8GB of RAM -
RAM is faster than SSD and the linux kernel data cache is more effective
than firmware data cache. (If your OS is Windows or MacOS with brain dead
data caching, then sure, hybrid HDD may be a good idea).

-- 
Konstantin Olchanski
Data Acquisition Systems: The Bytes Must Flow!
Email: olchansk-at-triumf-dot-ca
Snail mail: 4004 Wesbrook Mall, TRIUMF, Vancouver, B.C., V6T 2A3, Canada