Getting the Most Out of the Classic Mac OS

Dan Knight - 2004.07.16

Although initially geared to optimizing use in a prepress house, most of these suggestions are universally applicable. Many of the suggestions also apply to using the classic environment in OS X, especially the tips for reducing the number of extensions and control panels as much as possible.

This has been floating around the Internet without attribution for some time. I know it originated with Low End Mac because of the comment with my initials. Searching our archives, I find no trace of this article, so I'm editing, updating, and (re)posting it for those who continue to use the classic Mac OS. Opinions are those of the original author. dk

Optimizing for General Use

Set the maximum disk cache in the Memory control panel. The larger the disk cache, the more of the system file is stored in memory, and the larger a section of a large application is also stored in memory.

Use Extensions Manager to eliminate all unnecessary extensions and control panels. Elimination of unneeded extensions and control panels reduces the amount of overhead and interrupts on the machine - toys and neat desktop tricks can easily slow down a machine 5-10% or more.

Especially important is disabling any unused printer drivers - the Mac OS constantly scans for these extra printers, even when no printer using it has been selected. By reducing the search and not loading those resources on startup, you can visibly increase performance.

Use CD-ROM Toolkit for machines with CD-ROM drives. Apple's driver is crap - bulky and slow, constantly polling and taking up resources. CDT is written correctly.

Find, buy, steal, beg or borrow Conflict Catcher - not only is it a good way to easily manage extensions on your Mac, but it also has the ability to add to the system heap (using the "guarantee system heap" option). This is very important, because it's not addressed properly in any Mac OS release - the system heap should be set to 512k (ignore the percentage). This visibly increases system performance.

Be vigilant in optimizing the hard drives - keep them clean and running fast. Just 1% fragmentation of system files can lead to a 10% slowdown in performance. Drives in a prepress house should be optimized and checked every Friday before everyone goes home. The first two two will take a couple of hours - after this it will probably take just 15 minutes. Make it the last thing done before anyone goes home for the weekend, which also gives them 15 minutes off the computer to tidy things up and get ready to head home. [Norton Speed Disk 3.5 and later is much faster than older optimizers. dk]

Reduce the number of menu patches, especially in PPC mode. If you look at the Conflict Catcher (CC) report, you'll be able to see how patches to the menu bar end up slowing down PPC functions because they're PPC code patched over with 68k code. Even CC does this, so remove the pull down menu for CC and try to make sure no one else is using menu patches like this.

Using Mac OS 7.6.1 or lower, Now Menus (part of Now Utilities) is a good menu solution, while every other menu option I've found is a literal disaster. If you're using 8.1, then FinderPop is a better solution, using the Contextual Menu Manager (Pop up menu). [Editor's note: I still love and use MenuChoice, which is fast, works with System 7 right through 9.2.2, and doesn't seem to have any stability problems. dk]

For machines without a PowerPC processor, remove all PPC code from the System file using a program called PowerPCheck. It will remove roughly 1.6 MB of the System file, making the system run 30% faster. Of course, if this is a PPC upgraded Mac, you need that code! For all conventional 68040 machines, OS 8.1 is a real boon. Mac OS 8.1 is closer to pure '040 code and routinely acts much faster than System 7.5.5 or OS 7.6.1. If possible, standardize on this version.

If you have '030 machines, don't go beyond System 7.5.5 - 7.6 and 7.6.1 are a disaster.

Optimizing for Photoshop

If you run Photoshop, you should create a 4 MB RAM disk that is always active. Set the Primary Scratch disk to this 4 MB RAM disk and the Secondary to whatever hard drive you desire. The reason for this is simple: Photoshop has it's own virtual memory scheme, and even though you might have 80 or 90 MB set aside for Photoshop, it will always store it's toolboxes and filters in the scratch file, no matter what. The organization of this file is unique - all the sort headers, plus the active tools, are always at the top of the file - about the first 2 to 3 MB.

If a RAM disk is used as the first scratch disk, all of these tools are instantly available in memory, and you'll see the difference the first time you perform a filter such as a Gaussian blur. If you've noticed, the OS isn't quick to respond and update when a filter in Photoshop is performed. When you set all of the settings in the filter and then hit "OK" to apply it, there is a 5-10 second delay - usually accompanied by a white square where the box was, and you continue to wait for the "Performing Filter" window to pop up with the thermometer bar telling you just how much has been accomplished.

With a 4 MB RAM disk, this is almost instantaneous, because the sort table and the filter are immediately available for use. You will notice that filter functions will also work 10-20% faster as well, as rebuilding the sort table during a filter function is not processor intensive, but is instead SCSI intensive - processing of the filter must be stopped to rebuild this sort table every few moments - with the sort being instant now, the filter basically goes along unfettered. This is the most important tip I can give to Photoshop users.

Optimizing Virtual Memory

If virtual memory (VM) is enabled, it should always set to a multiple of 32 [see our Power Mac G3/266 benchmarks for more details - dk]. Hence, a machine with 72 MB of memory needs to have VM set to at least 96 MB. This is because the Mac OS prefers to make 4 MB block transfers, and the sort table inside VM is much easier to work with if it's a direct multiple, instead of having to figure out how to deal with an extra MB floating at the end of the file or 3 MB outstanding. While I don't normally support VM in a prepress house, there are sometimes reasons it must be used.

I realize that by creating a RAM disk and setting the disk cache to 8 MB, I'm sacrificing 12 MB of crucial memory, but I still stand by this - if you're trying to pull every bit of horsepower out of the machine, these are necessary steps. Since you're in a prepress house anyway, getting a bit more money just to increase the memory on these machines shouldn't be that hard. For the performance boost it gives, the extra memory - allocated the way I've stated above - will increase computer performance by about 50%.