Re: i5 Cache Battery

[Pat Barber <mboceanside@xxxxxxxxxxxxxxxx>]

Disk drives have always had a form of cache since that
is the effective way to use high speed devices.

The "newer" disk cache is MUCH larger and allows the I/O
to be greatly reduced. The high performance cache is
coming from the disk controller, which takes the load off
the operating system. This "feature" is $$$ upgrade.

When the battery dies, the OS has to carry the load and
I doubt it would be considered slow, it is for anybody
accustomed high speed cache.

Disk I/O has always been the "speed factor" in midrange boxes.
With these new "jumbo drives" and fewer arms, disk cache is a
big deal.


Most pc's don't have a high performance disk controller since
they are NOT I/O bound. Large web servers would be the reverse
of that and would need some disk cache for decent performance.

You put your money down and you take your chances....


albartell wrote:


> Forgive my ignorance on the subject, but would that be one of the benefits
> to iSeries I/O vs. regular PC IDE drives?  That being they have buffered
> mechanisms built into both the hardware and OS/400 that provide significant
> performance increases.  When the cache battery dies is one experiencing I/O
> performance similar to what a PC IDE HD would give?