5.1 Suggested minimum system configurations for MLWorks on Windows

We recommend that you use an SGVA monitor with a resolution of 800x600 pixels or greater.

To run the Windows 95 version of MLWorks 2.0 we recommend at least 20 MB RAM. For running on Windows NT, we recommend at least 24 MB RAM.

The distribution directory for Windows 95 and Windows NT is 9 MB; the installed system takes up around 23 MB. Therefore, during installation you will need around 32 MB of free disk space.

The following notes present suitable system settings for running MLWorks on Windows. They should help you optimize the performance of MLWorks on your Windows system.

Ensure a reasonable amount of disk space. 64MB would be plenty for most applications.

You can control the memory usage by the -limit n option to the MLWorks runtime itself, and also by setting the swap characteristics of Windows. The settings depend on the sort of work you are doing, for example student work, running a medium-sized application, or large-scale software development (all figures in MB):

Table 1 Recommended Windows memory settings (in Megabytes)
	Personal	Professional (medium)	Professional (large)
~live data	16	24	32
~max. heap size	32	48	48 (no `-limit`)
suitable `-limit` value	32	48	64
~max. heap size	24	32	40 (with `-limit`)
suitable RAM	16	24	32
reserved swap	64	64	128
minimum swap	23	32	32

The -limit in Table 1 refers to the -limit n option to the MLWorks runtime, which specifies an advisory arena extent size in MB. The default is 100. If you have problems with memory usage, try this setting first, using the suggested n from the table above. To change it, edit the mlworks shortcut by choosing Start > Settings > Taskbar, then in the Taskbar properties dialog, choose Start Menu Programs and click on the Advanced ... button. This explores the start menu programs. Find and select the mlworks shortcut and choose File > Properties. Then choose Shortcut. The shortcut is presented in the Target text box, and can be edited there.

Reserved swap is how much disk space you should have available to your virtual memory system. This is what determines whether MLWorks will die from lack of memory.

Minimum swap is the smallest size you should allow your swap file to become. You can set this in the Control Panel under System. The operations necessary differ between Windows 95 and Windows NT.

On Windows 95, select the Performance page, then click on the Virtual Memory... button in the Advanced Settings pane. Then select the Let me specify radio button and fill out the fields appropriately.

On Windows NT, select the Performance page, then click on Change... in the Virtual Memory pane. Then fill out the fields appropriately.

If you still have trouble, we suggest using the Windows 95 System Monitor or Windows NT Performance Monitor.

In the Windows 95 System Monitor (Start > Programs > Accessories > System Tools > System Monitor), select Edit > Add Item. In the Category list, select Memory Manager, then from Items choose "Swapfile in use" and "Swapfile size". Click OK.

In the Windows NT Performance Monitor (Start > Programs > Administrative Tools [ Common ] > Performance Monitor), select Edit > Add to Chart. Choose "Paging File" from the Object drop-down list and "%Usage" from the Counter drop-down list. Click Add.

The next thing to do is to monitor the chart while you are performing typical tasks in MLWorks. There is a danger that readings will disappear from the chart too quickly for you to interpret them. To avoid this, slow down the display by selecting Options > Chart and changing the "Update interval" slider setting (Windows 95) or Update Time interval setting (Windows NT).

Diagnosis again differs between Windows 95 and Windows NT. On Windows 95, if the swapfile size goes up and down a lot, the minimum swapfile size should be increased. If the swapfile size does not go up and down at all, the minimum swapfile size could be reduced. A suggested number in either case is 4/3 of the peak value of "Swapfile in use".

On Windows NT, if the paging file usage stays very low, your PC is not paging very much and you need not make changes. If the usage gets very high, you need to reduce the value of -limit used by the MLWorks runtime, or reduce the maximum paging file size, or do fewer tasks at once.

Also of interest for monitoring on Windows NT is the "Memory" object and its "Page Faults/sec" counter. If this remains high (over 100, say; though the exact number depends on your PC) for a prolonged period, you are thrashing and need to reduce your -limit, get more physical memory, or do fewer tasks at once. Note that the Performance Monitor graphs are scaled independently of each other.