"Rita Berkowitz" <ritaberk2...@[EMAIL PROTECTED]
> wrote:
> -hh wrote:
> > Since contem****ary OS's run virtual RAM and swaps out to the Hard
> > Drive (HD) whenever the user has more stuff running than physical RAM,
> > the system's performance takes a hit from the I/O access speed
> > differences between RAM and HD.
>
> That's your misunderstanding of how CS3 manages these files and utilizes
> memory. =A0In a batch process of 150 D3 RAW files you will never break
the=
> 1.5GB memory barrier if you have acceptable disk I/O.
But unfortunately, when your total system only has 1.5GB, the overhead
from other activities will never let Photoshop reach this 1.5GB limit.
YMMV on what else you choose to leave running, but between the OS,
Mail, Browser & background tasks, its not unusual to have 800MB-1GB of
real memory allocated. With the Rita 1.5GB system, this only leaves
~700MB of Real memory available for Photoshop...roughly half of the
above claimed limit.
> > This is why there's a performance gain from adding more physical RAM,
> > and that this is more significant than Disk I/O - - simply put, RAM I/
> > O is faster than any hard drive configuration in existance today.
>
> I agree with you when one upgrades from 1GB to 2GB or RAM. =A0
Well, you had better go tell that to the "Other Rita", who on 3/25/08
claimed that even 2GB of RAM is a waste:
"You can have 10GB of memory and it aint making any
difference....Anything past 1.5GB of RAM is a waste for Photoshop."
> RAM I/O speed is irrelevant because you have to get your
> filed from and back to the disk.
Disk I/O is relevant only when opening & closing the file. For all of
the other image manipulating actions, its CPU and RAM that determine
how long it will take. It depends on what you're doing as to which
ultimately takes "longer", but the fact remains that substituting Disk
Swap for Physical RAM **always** increases the timeline.
> > Granted, these performance gains will be an area of dimini****ng
> > returns, since the RAM is displacing Disk I/O. =A0Dimini****ng returns
> > means that the first +1GB of RAM has more benefit than the next +1GB
> > of RAM added, etc.
>
> Well, 1.5GB is the sweet spot for CS3.
2^30 =3D 1GB and 2^31 =3D 2GB; 1.5GB is approximately 2^30.5.
Now how can a non-integer value of bits to have rationality as a
memory addressing limit? Or was it simply an arbitrary value written
into a Photoshop subroutine that's intended to avoid it from hogging
some perceived value of "too much" from the OS's RAM?
Unfortunately, without Rita providing a URL to a Geocities webpage
that is a screenshot of Rita's "Activity Monitor" screen, to see RAM &
VM allocations, Page In/Out values, etc...this is an empty claim.
> > Thus, when someone like "Rita" claims that anything more than 1.5GB of
> > RAM is a "waste", they're merely speaking for their level of personal
> > need. =A0Thus, I'm not surprised to hear "Rita" claims.
>
> Could be since batching 150 D3 RAW files really is just a blip on the
old
> SCSI I/O.
If you're running a batch on 150 files that's doing just one or two
simple actions and then resaving the file, then disk I/O might be your
predominant time factor. However, it is trivial to determine how much
difference physical RAM contributes to your process: time how long it
takes to do a batch of 100, then open the PC's lid, pull some RAM and
time how long it takes to run another batch of 100 (ideally the same
100). If your system isn't already choked, it will be obvious when
you start to get into serious disk-swapping...and if you don't see any
difference, your system needs more RAM. Re****t back your results,
with nice PowerPoint Charts.
> > For everyone else, the metric to use is to examine one's Page-In/Page-
> > Out ratio after a period of typically serious use of Photoshop, etc,
> > to then decide if the frequency with which the OS hits the HD due to
> > lack of Physical RAM is acceptable to them or not.
>
> I haven't broke the 1.5GB barrier yet and don't know anyone else that
has.=
It might be rare, but not impossible:
<http://www.huntzinger.com/photo/2008/activity.jpg>
> If a person is breaking the 1.5GB barrier they are doing something
serious=
ly
> wrong.
Or merely something different than 'Rita'.
FYI, the above do***ented use of 1.6 real + 2 VM (3.7GB total) was
from just two Photoshop files being open from the same project, namely
the full scan of a Kodachrome @[EMAIL PROTECTED]
200 MP (17,433 x 11,551) and its
first downsample to 8674 x 5776 (50 MP).
-hh
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