Hi,
I'd ask two questions:
1) how much spare CPU is available?
If there's a lot, but you feel performance is slow,
then you might be memory bound. If there's
little CPU available, then adding more memory probably won't
gain much performance (except for a small amount of savings in
slightly reduced amount of CPU used for page fault handling) because
there isn't spare CPU horsepower available to take advantage of
the extra memory.
You can check for free by going to the hardware console (ldev 20),
and pressing Control-B, so you can see the status line ...
Note that the left edge alternates between FFFF and FxFF. That
'x' * 10 is how busy your CPU was for the last second or so.
Thus, F3FF means your CPU was 30% busy.
2) How is your memory being used now?
You can get the free RAMUSAGE utility from:
http://www.allegro.com/software/
or directly at: http://www.allegro.com/software/stuff/RAMUSAGE.LZW
It will tell you how your memory is used by "category", and
tell you how much more "user" memory would be available if you
added more memory. Example:
:run ramusage.pub
RAMUSAGE [2.29] - LPS Toolbox [A.01j] (c) 1995 Lund Performance Solutions
SERIES 968RX
MPE/iX 5.0
#CPUS: 1
Memory size: 128 MB (134,217,728 bytes; 32,768 logical pages)
Memory usage by "type" of Object Class:
Class #LogicalPages #MB % total
------------- ------------- --- -------
SYSTEM_CODE 5,784 22 17.7%
SYSTEM_DATA 11,428 44 34.9%
UNUSED 608 2 1.9%
USER_CODE 7,665 29 23.4%
USER_DATA 614 2 1.9%
USER_STACK 817 3 2.5%
USER_FILE 5,851 22 17.9%
Totals: 32,767 127 100.0%
"User" pages are 47.5% of memory (61 MB out of 128 MB)
If you added:
32 MB, you'd have 1.5 times as much "User" memory. ( 160 total MB)
64 MB, you'd have 2.0 times as much "User" memory. ( 192 total MB)
96 MB, you'd have 2.6 times as much "User" memory. ( 224 total MB)
128 MB, you'd have 3.1 times as much "User" memory. ( 256 total MB)
160 MB, you'd have 3.6 times as much "User" memory. ( 288 total MB)
192 MB, you'd have 4.1 times as much "User" memory. ( 320 total MB)
224 MB, you'd have 4.7 times as much "User" memory. ( 352 total MB)
256 MB, you'd have 5.2 times as much "User" memory. ( 384 total MB)
288 MB, you'd have 5.7 times as much "User" memory. ( 416 total MB)
320 MB, you'd have 6.2 times as much "User" memory. ( 448 total MB)
352 MB, you'd have 6.8 times as much "User" memory. ( 480 total MB)
384 MB, you'd have 7.3 times as much "User" memory. ( 512 total MB)
This report is a small subset of the data provided by PAGES, one of the
utilities in the Toolboxes from Lund Performance Solutions.
Lund Performance Solutions can be reached at (503) 926-3800.
OTOH, there's the short answer:
> Advice, please, as to how much memory we should have.
Money_available / price_per_MB = Amount of MB to buy
--
Stan Sieler [log in to unmask]
http://www.allegro.com/sieler.html
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