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	Memory Usage There are a number of things you can do to increase system performanceand productivity. One of the first things we usually think of is simply to plug in more memory. While this willlikely boost your system performance, there are settings in Windows NT that can enable more efficient use of yoursystem's memory. Here are some of the most significant ones that we have found workable: L2 Cache If you have more than 256 kilobytes of L2 cache, Windows NT may notbe using all of it. To correct this: Run Regedt32.exe Bring up the window HKEY_LOCAL_MACHINE (on the local machine) Select SYSTEM \CurrentControlSet \Control \Session Manager \MemoryManagement On the right side of the window you will find SecondLevelDataCache.This defaults to 0, which is the correct value for 256 kilobytes of L2 cache. Double-click SecondLevelDataCacheto bring up the DWORD Editor. Click the Decimal radio button, enter the amount of L2 cache you have, then clickOK. Exit RegEdt32, and your machine should be a lot faster. If you don't know how much L2 cache you have, you may be able to findout during boot-up. Each brand of BIOS has its own display format, but look for "L2 Cache", "SecondaryCache", or something like that. The value should be 256, 512, or 1024. I/O Rate If your system is fairly I/O intensive, you may benefit from raisingthe I/O Page Lock Limit, which can increase the effective rate at which data is read from or written to the harddisks. First, benchmark your common tasks. See how long it takes to loadand save large files, how long it takes to search a database or run a common program; just do your normal tasks,timing them to record how fast they are. Then follow these steps: Run Regedt32.exe. Bring up the window HKEY_LOCAL_MACHINE (on the local machine) Select SYSTEM \CurrentControlSet \Control \Session Manager \MemoryManagement On the right half of the window, double-click IoPageLockLimit Click the Decimal radio button This value is the maximum bytes that can be locked for I/O operations.A value of 0 defaults to 512 kilobytes. Raise this value by 512-kilobyte increments, exiting regedt32 and benchmarkingyour system after each increment. When an increase does not give you a significant performance boost, go back andundo the last increment. Caution: There is a limit to this. We recommend you do not set thisvalue (in bytes) beyond the number of megabytes of RAM times 128. That is, if you have 16 megabytes RAM, do notset IoPageLockLimit over 2048 bytes; for 32 megabytes RAM, do not exceed 4096 bytes, and so on. That's the safe method. You may be adventurous or impatient and wantquick results. If so, try this: Benchmark Calculate your maximum IoPageLockLimit value (megabytes of RAM times 128) Set IoPageLockLimit to half this value Benchmark again. If you get little or no improvement, work down by 512 byte decrementsuntil you note a drop in performance, then go back up 512 bytes. If you did see an improvement, continue with step5. Raise IoPageLockLimit to ¾ of the maximum Benchmark again If you get little or no improvement in the third benchmark, work downin512 byte decrements. If you do get improvement, work up from ¾ maximum. And if the first increase from ¾shows little improvement, work down from ¾. Unless you don't do much I/O, this should give you a significant boostin performance. Printer Memory Windows NT may be set up for more printer memory than it really has.If you get error messages, or printouts are sometimes incomplete, check this out. Also, if you add memory to yourprinter, you will probably have to change Windows NT settings. Click Start and select Settings then Printers. Double-click the iconfor the printer. In the box that opens, click Printer, Properties, then the Device Settings tab. Select InstalledMemory. If the value displayed is different from the amount of memory in your printer, change it, then click OKand exit to the desktop. If this does not fix your printing problems, check the other settingsin Print Manager. If everything is OK there, you may need an updated printer driver. These are usually availablefor free download from the manufacturer's web site. If all else fails, uninstall and re-install the printer driver. What is Using Your Memory? To find out how much memory each application is using, the first thingto do is click Start, then go to Programs, Administrative Tools and Windows NT Diagnostics. Click the Memory taband look at Physical Memory in the upper right hand section. This tells you how much memory you have and how muchis available. Also note the section below this, Kernel Memory; this is what Windows NT itself is using. Then pressCTRL+ALT+DEL and click the Task Manager button, then the Processes tab. This lists the existing processes. If itdoes not have columns titled Mem Usage and VM Size (Virtual Memory), go to the menu bar and click View, then SelectColumns and check the boxes for Memory Usage and Virtual Memory Size. Now you can see just how much memory eachprocess is currently using. Add the VM Size value and you have the amount of memory the process actually uses.If the Physical Memory is low (a few thousand or less), you definitely need more RAM. Incidentally, in the same Windows NT Diagnostics window, you willfind Pagefile Space. If the Peak Use value is anywhere near the Total value, you should make a larger paging file,or create another paging file on another partition; a large single paging file is generally faster than two smallpaging files.   If you have any comments about this article orany requests for new technical articles e-mail
	Executive Software Europe