Re: Windows 7 and all my Java stuff.

From:

Patricia Shanahan <pats@acm.org>

Newsgroups:

comp.lang.java.programmer

Date:

Thu, 07 Jan 2010 06:32:30 -0800

Message-ID:

<IYydnW7-84PibdjWnZ2dnUVZ_rydnZ2d@earthlink.com>

Roedy Green wrote:

On Wed, 06 Jan 2010 21:09:49 -0800, Peter Duniho
<NpOeStPeAdM@NnOwSlPiAnMk.com> wrote, quoted or indirectly quoted
someone who said :

I wonder how long before mass-storage and virtual RAM are unified so
that mass storage is accessed as a dedicated part of virtual RAM.

You've been able to do that for years. It's called memory-mapped files.

That is not what I mean. I mean at a hardware level, that the
hardware CPU (not the application program) sees as what it thinks is
245TB bank of RAM. However the RAM "chips" fake this with a firmware
managed virtual RAM system of several layers of cache, perhaps even at
the lowest level accessing the net.

....

What advantage do you see to managing this from firmware rather than
operating system software, as is done in current implementations of
memory-mapped files?

Hardware and firmware are less flexible and harder to update than the
operating system. Hard wired decisions have to be kept simple.
Performance is the usual reason for moving memory hierarchy layer
management into hardware or firmware, despite those disadvantages. That
does not apply to the disk layer, given disk access times and block sizes.

Patricia