QUESTION:
What is the correct -qcache option for the M390 (both with and without)
the optional L2 cache?
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A: The model 390 does not have an entry in the tables in Appendix C
of the "Optimization and Tuning Guide for FORTRAN, C, and C++"
(SC09-1705-00), but we have determined that the values would be:
Data Cache Size: 64K
Data Cache Set Associativity: 4
Data Cache Line Size: 64
Data Cache Number of Lines: 1024
Instruction Cache Size: 32K
Instruction Cache Set Associativity: 2
Instruction Cache Line Size: 128
Instruction Cache Number of Lines: 256
Data TLB Entries: 512
Set Associativity: 2
Instruction TLB Entries: 128
Set Associativity: 2
The level 1 cache for the 390 comprises an independent data cache and
instruction cache. This is true for all POWER2 machines. Therefore,
one should specify for type=D and type=I on separate -qcache
command lines, if the user figures it to be worthwhile, given his
particular application. This has no dependence on whether the
machine has a level 2 cache or not.
The level 2 cache can also be specified, but on a separate line.
The level 2 cache contains both instructions and data and therefore
one should use type=C in the -qcache command line as below:
-qcache=type=C:level=2:size=512:line=256:assoc=2
If one does not have a secondary cache, simply do not include the
above line.
Thank you.
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This item was created from library item Q676521 FFJJF
Additional search words:
AUTO AUTOMATIC CACHE COMPILERS CORRECT CORRECTION CORRECTIVE DEC94
FFJJF IX L2 M390 OPTION OPTIONAL OPTIONS OZIBM OZNEW QCACHE RISCL
RISCSYSTEM SOFTWARE
WWQA: ITEM: RTA000052830 ITEM: RTA000052830
Dated: 10/1996 Category: RISCL
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