home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Power CD-ROM!! 8
/
Power CD-ROM 8.iso
/
os2
/
perf31
/
optimize.hlp
(
.txt
)
< prev
next >
Wrap
OS/2 Help File
|
1994-10-29
|
28KB
|
741 lines
ΓòÉΓòÉΓòÉ 1. General Help ΓòÉΓòÉΓòÉ
General Help for the Config.Sys Optimizer
The Optimizer has all of the performance oriented Config.Sys parameters on a
single page (screen).
The values shown in black are the values from your Config.sys file. They may
be modified individually by changing the entries either directly by using the
tab key or mouse pointer and changing the value, or by using the spin arrows,
check boxes or radio buttons.
The Optimizer has recommended values for your system indicated in red. These
values are specific to your system type and memory size. These values can be
applied by pressing the Set button (red). This action will place all of the
recommended values into their corresponding entry fields.
After changing the fields to your preference, pressing the Apply Changes button
(also in red) will update your Config.Sys. It will optionally make a copy of
your Config.sys, if you check the box marked Create backup.
Additional help is available for each parameter. Tab to the parameter in
question, and press the F1 key. There are also hints about each field that
appear on the bottom of the screen as you move the mouse pointer over the field.
Feel free to explore all of the fields. Remember, changes are not applied to
Config.Sys until you press the Apply Changes button. All of the values are
validated, so you can be assured that an invalid parameter can't be entered.
ΓòÉΓòÉΓòÉ 2. Processor Type ΓòÉΓòÉΓòÉ
OS/2 V2 & V3 both exploit the processor instruction set of the Intel 386
processor. Computer processors that include the 386 instruction set should be
able to run OS/2. The Intel 486 and Pentium processors certainly qualify and
are the most pervasive. Please specify your processor type as a 386, 486 or
Pentium.
ΓòÉΓòÉΓòÉ 3. Speed ΓòÉΓòÉΓòÉ
CPUs are available with different clock speeds, often referred to as Megahertz
(Mhz). The clock determines the time it takes the processor to cycle through
one operation, for example, the execution of a single instruction. Some
instructions do require multiple cycles so this is not always the most accurate
way to measure the performance of a processor, but it will serve our
discussion. A faster clock speed indicates a faster CPU within that processor
family, (e.g. a 386-33Mhz is faster than a 386-25Mhz but not faster than a
486-25Mhz). When the 586, or Pentium as it is currently being named, becomes
available it will be 386 compatible and faster
than a 486.
Another group of processors available that use technique called clock doubling
or tripling. This means that the CPU operates at two different speeds depending
on the operation it is performing. Internal operations execute at the faster
speed. This includes all instruction operations that are internal to the CPU
chip. The cache located on the 486 chip makes this an effective technique for
improving performance, since it also operates at the faster speed. For
external (to the CPU chip) operations, the processor operates at the slower
cycle speed. This reduces the speed requirements of the components directly
interfacing with the CPU, (and thus their cost). System board memory and local
bus components will interface at this slower cycle speed.
An example of one of these processors is the Intel 486DX2/66. It has an
internal processor speed of 66MHz. When this processor accesses memory on the
system board it does so at 33MHz or half the internal rate.
Please choose the clock speed that your computer executes. If its rate is not
shown, then choose a rate that is close.
ΓòÉΓòÉΓòÉ 4. Memory ΓòÉΓòÉΓòÉ
The place that programs and data must be at the time when the CPU needs them.
Often called RAM (Random Access Memory), it is a set of very fast electronic
chips that temporarily stores data and programs for the computer's use. When
you power down your system, RAM memory is cleared. A minimum of 4MB of this
memory is needed for OS/2 to effectively operate. Many people get confused
between memory and disk storage because both are measured in MBs and both hold
your programs and data. Unlike memory, your data and programs remain on disk
storage even after you power down your system.
OS/2 can use between 4 and 64 MBs of memory.
ΓòÉΓòÉΓòÉ 5. Cacheing ΓòÉΓòÉΓòÉ
This is the best technique you can use to improve the effectiveness of your
CPU. Our testing shows that cache memory for HPFS and/or FAT is a great use of
memory. Always keep in mind that memory used this way is taken away from
overall memory, and while it may improve your CPU's effectiveness, overall
performance could be reduced due to increased page swapping.
ΓòÉΓòÉΓòÉ 6. HPFS Partition Cacheing ΓòÉΓòÉΓòÉ
IFS=C:\OS2\HPFS.IFS /CACHE:xxx /CRECL:yyy /AUTOCHECK:d,e,f
This parameter is only specified in CONFIG.SYS. Its presence activates the
HPFS file system and it must be present for you to access your HPFS partitions.
If you have no HPFS partitions, then delete this statement and save 500+KB of
your system memory.
ΓòÉΓòÉΓòÉ 6.1. CACHE ΓòÉΓòÉΓòÉ
HPFS CACHE
This is the best technique you can use to improve the effectiveness of your
CPU. Our testing shows that cache memory for HPFS is a great use of memory.
Always keep in mind that memory used this way is taken away from overall
memory, and while it may improve your CPU's effectiveness, overall performance
could be reduced due to increased page swapping.
/CACHE:xxx, where xxx specifies the amount of memory in KB that is used for
HPFS cache. The default is 10% of the available system memory, and the maximum
is 2048KB.
ΓòÉΓòÉΓòÉ 6.2. CRECL ΓòÉΓòÉΓòÉ
HPFS Cache Maximum Record Length
/CRECL:yyy, where yyy specifies the maximum record size in multiples of 2KB
that will be eligible for caching. The Minimum is 2KB, the Maximum is 64KB and
the default is 4KB.
This value can be an important performance parameter as it represents the
largest size an I/O activity can be, and still be read into cache. Setting this
too small could limit the usage of your cache. We recommend that you chose as
large a Cache and CRECL as you can afford.
ΓòÉΓòÉΓòÉ 6.3. AUTOCHECK ΓòÉΓòÉΓòÉ
HPFS Autocheck
/AUTOCHECK:d,e,f specifies any additional drives, (other than the boot drive),
that OS/2 should check at startup to determine if the file system associated
with that particular drive(s) is in an inconsistent state.
This might occur because of improper shutdown. If inconsistencies are found
the operating system will execute the CHKDSK command with the /F option to
attempt to correct any problem.
This is highly recommended that you include every HPFS drive in this list!
ΓòÉΓòÉΓòÉ 6.4. REMOVE IFS=HPFS ΓòÉΓòÉΓòÉ
You'll only see this check box if your system has NO HPFS Partitions and the
IFS=HPFS.IFS statement appears in your CONFIG.SYS. If this is the case, the
High Performance File System is being loaded into your memory during the boot
process. A cache is allocated and set aside for HPFS exclusive use. IN OTHER
WORDS - valuable memory is being wasted because you have NO HPFS PARTITIONS! A
half MB or more of your expensive memory is being lost. All you need to do to
regain the use of this memory is remove the IFS=HPFS.IFS statement from your
CONFIG.SYS or let the Optimizer do it for you by checking the Remove
IFS=HPFS.IFS check box.
ΓòÉΓòÉΓòÉ 7. FAT Partition Cache (DISKCACHE) ΓòÉΓòÉΓòÉ
DISKCACHE=xxx,LW,threshold,AC:cdef This command may only be placed
in CONFIG.SYS. It creates a cache for use by those fixed disk partitions
formatted as FAT. It will not provide a caching facility for diskette or
network disk drives. HPFS does not use memory allocated for FAT cache. If
there are no FAT partitions in your system, deleting or REMing this statement
from your CONFIG.SYS will save memory.
ΓòÉΓòÉΓòÉ 8. FAT Partition Cacheing ΓòÉΓòÉΓòÉ
ΓòÉΓòÉΓòÉ 8.1. CACHE ΓòÉΓòÉΓòÉ
FAT CACHE
DISKCACHE=xxx
xxx is the amount in KB to set aside for the cache. For OS/2 version 2 it may
be a value between 64 and 14400.
There is a new minimum value of 48KB for OS/2 Version 3. Version 3 also has an
alternate choice of "D" for this value. "D" stands for a dynamically allocated
default. The default varies based on total system memory. 48KB is used for a
4 MB system, for 5-6 MB system 128KB cache size is set, 6-8MB systems are set
to 512KB, and for systems with more than 8MB of memory the cache size allocated
is 10% of system memory.
The Performance PLUS V3 Optimizer is more conservative than the system defaults
for systems with 5-8MB. In systems this size memory is better used for
applications than for cache.
On larger systems the Optimizer recommends larger cache sizes than the default.
This is a good parameter to tinker with as each system has different needs -
and changes will surely affect performance (either positive or negative).
Remember to run SimpleCount before and after each change to measure the effect
of the change.
ΓòÉΓòÉΓòÉ 8.2. LAZY ON/OFF ΓòÉΓòÉΓòÉ
FAT LAZY WRITE
DISKCACHE=xxx,LW
Lazy Write (LW) is a highly recommended performance feature of the DISKCACHE
statement. It tells the FAT file system to delay writing data to the disk
until the drive has idled.
This means that when your application asks the file system to write the data,
OS/2 responds as soon as the data is placed into the memory cache rather than
wait until the data is actually written onto the disk drive. This will
dramatically improve the performance of most applications.
Many people have fears that lazy write will increase the likelihood of lost
data. The delay mentioned above is usually measured in seconds. Should a
power failure occur, only the data not written from the cache to disk would be
lost (the past few seconds of data (if any). In other words, the potential for
additional lost data is minimal when lazy write is ON.
Unless your program is a mission critical program that uses a transaction
logging scheme for data recovery, I recommend taking advantage of the
performance improvements offered by lazy write.
ΓòÉΓòÉΓòÉ 8.3. THRESHOLD ΓòÉΓòÉΓòÉ
FAT Record Threshold
DISKCACHE=xxx,LW,ttt
ttt is the threshold size, which specifies the number of disk sectors that will
be placed into cache when an I/O operation is initiated by your application
program.
The threshold should be as large as possible but not larger than ╨╝ of the total
size of the cache. Since most disk drives have a sector size of 512 bytes, 2
sectors equal 1 KB.
A value of 10 for ttt equates to 5 KB (for most disk drives).
For example, a cache (xxx) of 64 should have a ttt value of 32 (resulting in a
16KB threshold size or ╨╝ of the 64KB Cache) . Vary this with sector size.
The maximum value for ttt is 128, and should be used if your cache is 256K or
larger.
ΓòÉΓòÉΓòÉ 8.4. AC: ΓòÉΓòÉΓòÉ
FAT Autocheck
DISKCACHE=xxx.LW,ttt,AC:defg
AC:defg specifies any additional drives, (other than the boot drive), that
OS/2 should check at startup to determine if the file system associated with
that particular drive(s) is in an inconsistent state.
This might occur because of improper shutdown. If inconsistencies are found,
the operating system will execute the CHKDSK command with the /F option to
attempt to correct any problem.
It is highly recommended that you include every FAT drive in this list!
The Optimizer checks all drives available on your system and recommends that
the FAT drives be placed into this list.
ΓòÉΓòÉΓòÉ 8.5. D - Dynamic DISKCACHE Default ΓòÉΓòÉΓòÉ
FAT Diskcache
DISKCACHE=D,LW,ttt,AC:defg
D is a new option for DISKCACHE with OS/2 Warp Version 3. "D" stands for a
dynamically allocated default. The default varies based on total system
memory.
48KB is used for a 4 MB system.
128KB is set for a 5-6MB system.
512KB is set for a 6-8MB system.
10% of memory set for systems with more than 8MB.
ΓòÉΓòÉΓòÉ 8.6. Remove DISKCACHE ΓòÉΓòÉΓòÉ
The Optimizer detected a DISKCACHE statement in your Config.Sys and NO FAT
Partitions. This means that a Cache has been set aside for FAT partitions but
will not be used for anything. The FAT cache does not cache diskette drives
nor LAN Network drives. Remove this DISKCACHE from your Config.Sys to reclaim
this memory or check this box for the Optimizer to remove it for you.
ΓòÉΓòÉΓòÉ 9. Program Management ΓòÉΓòÉΓòÉ
Program Management
This group of settings allow you to control the execution of the various
applications being multitasked in your system. Included are:
o MAXWAIT
o
o THREADS
o
o PRIORITY_DISK_IO
o
o PRIORITY
o
o IOPL
o
o TIMESLICE
ΓòÉΓòÉΓòÉ 9.1. MAXWAIT ΓòÉΓòÉΓòÉ
MAXWAIT - Task Management
MAXWAIT=xxx sets the length of time, in seconds, that a thread waits before the
system will assign it a higher priority.
The default is 3 seconds, you may specify a number from 1 through 255. Setting
this to 1 could help applications with a significant I/O orientation, but it
could also increase the overhead processing of OS/2 since OS/2 would check
every 1 second rather than the default of 3.
Under certain circumstances very fast processors (Pentium and 486DX4) can
benefit from a setting of 1 since a fast processor will be less likely to be
adversely affected by an increase in OS/2 overhead. Likewise a slow 386sx -
16Mhz processor might benefit from increasing this value to 5, which would
reduce the OS/2 overhead.
ΓòÉΓòÉΓòÉ 9.2. THREADS ΓòÉΓòÉΓòÉ
THREADS - Task Management
THREADS=xxxx sets the maximum number of tasks OS/2 will allow to be
concurrently activated. This can be between 64 and 4095. The default is 256.
This setting might be modified as your application habits change from DOS based
to OS/2 based applications. Since many OS/2 applications implement
multithreading the value will need to be increased as you migrate from DOS
applications. This parameter does set aside fixed resources for the maximum
number of threads. Start with a setting of 64 if your system is a minimum
memory system (4MB).
ΓòÉΓòÉΓòÉ 9.3. PRIORITY_DISK_IO ΓòÉΓòÉΓòÉ
PRIORITY_DISK_IO - Task Management
PRIORITY_DISK_IO=yesno
PRIORITY_DISK_IO allows you to change the default setting of YES that provides
priority disk access to the foreground application.
You may change it to NO to give equal disk I/O priority to all tasks.
Under special circumstances, such as a LAN file or application server, you
might want a background application to have better performance than the
foreground application; setting this to NO will enable this possibility.
Setting it to NO will probably adversely affect the performance of your
foreground application.
ΓòÉΓòÉΓòÉ 9.4. PRIORITY ΓòÉΓòÉΓòÉ
PRIORITY=DYNAMIC is the default method of OS/2 priority assignments. OS/2
varies the priority of tasks dynamically, as their I/O and processor usage
change. You may specify ABSOLUTE to keep OS/2 from changing the priority of
tasks as they are running. DYNAMIC is our recommendation for all cases.
ΓòÉΓòÉΓòÉ 9.5. IOPL ΓòÉΓòÉΓòÉ
IOPL - Task Management
IOPL=YES
or
IOPL=list
IOPL allows you to grant all applications (YES), or a list of application names
(list), the I/O privilege level 2, rather than the default level 3.
The privilege level 2 gives an application the right to directly communicate
with a device. This might be a necessary performance requirement of an
application. Being assigned privilege level 3 restricts an application's
ability to directly communicate with a device.
The Optimizer recommends that this command be set to YES.
Example:
IOPL=YES
IOPL=FAXWORKD,QSYSTEM
ΓòÉΓòÉΓòÉ 9.6. TIMESLICE ΓòÉΓòÉΓòÉ
TIMESLICE - Task Management
TIMESLICE=nnn,xxx
Sets the (minimum,maximum) length of time a thread will be given to use the CPU
before it is interrupted by a thread having the same priority. All threads
having the same priority are scheduled in a round-robin algorithm.
OS/2 2.1 has implemented dynamic timeslicing to minimize the impact of
interrupt processing due to timeslicing. TIMESLICE=, when present in
CONFIG.SYS, overrides the OS/2 timeslicing default which uses a dynamic
algorithm. That is, the default timeslice period is dynamically changed as
system conditions change.
This dynamic algorithm is very efficient for most systems - override this
default only if you have a compelling reason.
ΓòÉΓòÉΓòÉ 10. BUFFERS ΓòÉΓòÉΓòÉ
BUFFERS
BUFFERS=xxx
This parameter may only be placed in CONFIG.SYS. The value indicated by xxx
specifies the number of 512 byte buffers to be setup at system startup for
reading and writing to files with data blocks smaller than your disk's sector
size also 512 bytes.
This parameter is very important if you are not using cache.
It is also important for improving the performance of disk partition directory
management.
The value for xxx, may be between 1 and 100. If you have HPFS and FAT
partitions, an equal number of buffers are allocated for each file system, that
is specifying BUFFERS=80 will allocate 160 buffers - 80 for your FAT partitions
and 80 for your HPFS partitions.
ΓòÉΓòÉΓòÉ 11. DOS ΓòÉΓòÉΓòÉ
The following set of values, when found in Config.Sys, become the default
values for all DOS sessions started. (You may override defaults for each
individual DOS program using that program object's settings.)
o FILES
o
o RMSIZE
o
o FCBS
o
o HIGH
o
o UMB
ΓòÉΓòÉΓòÉ 11.1. FILES ΓòÉΓòÉΓòÉ
FILES
FILES=xxx
This sets the maximum number of files that the DOS program may open using file
handles (as opposed to FCBS).
It sets aside 45 bytes of memory per file handle.
The default FILES=20 sets aside 900 bytes. Set this higher for those programs
that document a higher requirement.
Remember that setting this in CONFIG.SYS to the max of 255 will set aside
11.5KB of memory for each VDM started.
ΓòÉΓòÉΓòÉ 11.2. RMSIZE ΓòÉΓòÉΓòÉ
RMSIZE
RMSIZE=xxx
When a DOS program starts under OS/2 it runs in what is know as a VDM or
Virtual DOS Machine. RMSIZE defines the size of conventional memory for that
"virtual" machine. Valid values are 0 to 640KB.
Rarely will a program dictate that this value be other than 640KB. I have seen
a few situations when a value of 639 was needed.
ΓòÉΓòÉΓòÉ 11.3. FCBS ΓòÉΓòÉΓòÉ
FCBS - DOS only
FCBS=(xxx,yyy)
In the early days of DOS an application program used FCBS (File Control Blocks)
to control files (today most programs use file handles). The xxx value
specifies how many FCBS are to be put aside for your DOS program. If your
program uses FCBS it is usually documented. The default of 16 is usually
plenty and only wastes a small amount of memory, (44 bytes for each FCB).
Don't go overboard though for such a rarely used DOS parameter, after all 255 X
44 is over 11KB!
The yyy value tells DOS that a subset of the xxx FCBS are to be kept open.
This setting is rarely needed by today's DOS programs. The default of 8 is
more than plenty for most situations.
ΓòÉΓòÉΓòÉ 11.4. HIGH ΓòÉΓòÉΓòÉ
DOS=HIGH
DOS=(high,umb)
Use HIGH to provide your DOS program with additional available conventional
memory (below the 640KB barrier).
Specifying HIGH moves about 24KB of the DOS kernel to XMS (Extended Memory).
DOS=HIGH can also be set for each DOS program using the settings for that
individual program object. (Use the Performance PLUS V3 DOS BlackBox program
to vary the DOS settings.)
DOS=LOW is the default.
Setting DOS=HIGH requires that you have XMS_HMA_MIN set to at least 64.
DOS=HIGH is a good idea since many DOS programs need as much room below the
640KB line as they can get.
ΓòÉΓòÉΓòÉ 11.5. UMB ΓòÉΓòÉΓòÉ
DOS=UMB
DOS=(high,umb)
DOS=UMB is another technique to increase the available conventional memory
space for your DOS programs. This tells DOS to load TSRs and Device Drivers
into the Upper Memory Block area.
DOS=NOUMB restricts DOS from loading device drivers into the UMB area.
If you need a more detailed explanation than this, refer to the book.
ΓòÉΓòÉΓòÉ 12. Swap Management ΓòÉΓòÉΓòÉ
Setting Swapper Initial Size and Path
SWAPPATH=drive&path,xxxx,yyyy
This is another parameter placed in CONFIG.SYS. The values you can specify
are:
drive&path
This is shown in the normal manner, e.g. C:\OS2\SYSTEM. This will tell OS/2
where to allocate the SWAPPER.DAT file at startup.
ΓòÉΓòÉΓòÉ 12.1. SWAPPATH ΓòÉΓòÉΓòÉ
SWAPPATH
SWAPPATH=drive&path,xxxx,yyyy
This is another parameter placed in CONFIG.SYS. The values you can specify
are:
drive&path
This is shown in the normal manner, e.g. C:\OS2\SYSTEM. It tells OS/2 where to
allocate the SWAPPER.DAT file at startup.
Place SWAPPER on the most active partition of the least active physical drive.
This will improve the probability that the read/write heads will have a closer
proximity to the SWAPPER file. Additional advise on SWAPPER location is to
place it on a partition with plenty of free space - see additional information
about this with the MinFree parameter.
NOTICE: After changing the drive&path and after re-booting, remember to delete
the SWAPPER.DAT file from its old location to reclaim that disk space!
MinFree
xxxx specifies when OS/2 should warn you that the disk space available for
Swapper expansion is low.
If the Swapper needs to expand, and there is not enough room, OS/2 will stop.
The default value is 2048KB and probably should be higher - try 4096 or 5120.
Remember, if space on your swapper partition becomes full and the swapper needs
to expand the system will STOP COLD. You will need to reboot, losing work in
process and a long wait for your drive partitions to be checked.
If you are warned that this value is reached... stop what you are doing, and
immediately reduce your multitasking level. You should also perform some
housekeeping by deleting some nonessential files in this partition.
Initial Value
yyyy sets the initial size of the Swapper file at OS/2 startup. OS/2 sets the
default value based on your system's total RAM memory. Set this to the total
size Swapper expands during a normal session. This will insure contiguous file
space for Swapper, which is the most efficient allocation technique, and will
provide you the best page swapping performance.
Use the Performance 3.0 SeeSWAP Monitor utility to find the proper value for
this parameter.
ΓòÉΓòÉΓòÉ 12.2. MinFree ΓòÉΓòÉΓòÉ
ΓòÉΓòÉΓòÉ 12.3. Initial ΓòÉΓòÉΓòÉ
ΓòÉΓòÉΓòÉ 13. Controls ΓòÉΓòÉΓòÉ
The control buttons help simplify the manipulation of the values. They include:
o Set
o
o Clear
o
o Reset
o
o Apply Changes
o
o Exit
o
o Create Backup
ΓòÉΓòÉΓòÉ 13.1. Set ΓòÉΓòÉΓòÉ
Set
Pressing the Set button will apply the Optimizer recommendations to the entry
field values. That is, those values in RED will be chosen.
Toggle the values back by pressing the Reset button.
Press the Clear button to reset the values to their initial setting (when you
started the Optimizer).
ΓòÉΓòÉΓòÉ 13.2. Clear ΓòÉΓòÉΓòÉ
Clear
Pressing the Clear button will change the entry field values to the initial
settings (when you started the optimizer).
Once again, you may toggle the values with the reset button.
ΓòÉΓòÉΓòÉ 13.3. Reset ΓòÉΓòÉΓòÉ
Reset
Toggle the entry fields to the values prior to the last Set or Clear operation.
ΓòÉΓòÉΓòÉ 13.4. Apply Changes ΓòÉΓòÉΓòÉ
Apply Changes
Press the Apply Changes Button to capture all of the setting values on the
screen and apply them to Config.Sys and end the Optimizer.
A backup copy of Config.Sys will be made if the Backup check box is marked.
ΓòÉΓòÉΓòÉ 13.5. Exit ΓòÉΓòÉΓòÉ
Exit
End the Optimizer without applying any changes to Config.Sys.
ΓòÉΓòÉΓòÉ 13.6. Create backup ΓòÉΓòÉΓòÉ
Create backup
Optimizer will make a copy of your current Config.Sys before modifying its
values when the Apply Changes button is pressed.
Optimizer checks the root directory of your system boot drive for other
versions of your Config.XXX. It increments the largest value for the next
backup copy and displays that name next to the check box.
Optionally you may specify the name of the config.sys backup by entering the
name in the field.