a. Virtual memory delays Over the past several days I have gotten several reports of significant performance slow-downs linked to virtual memory being active. While details are still a bit sketchy, it appears to affect only Apple's virtual memory, not RAM Doubler. For example:
Jim Morrison reports: "I found that I was getting periodic slowdowns, some lasting minutes, with audible hard disk activity after upgrading to 7.6.1 on a Power Mac 7100/80 with 40 megs of RAM and virtual memory set to its minimum (41 megs) Turning off virtual memory eliminated the problem. Plain 7.6 worked great on this machine."
Bob O'Driscoll writes: "I could make 7.6.1 run properly on the internal IDE drive of my 5400 only by turning off virtual memory. The comparative speeds from Norton Utilities System Info Test Volume were:VM on: 66; VM off: 204." The problem did not affect his SCSI external disk.
Jeff Blume writes: If virtual memory is turned on (under 7.6.1 only), my MacBench Disk scores are cut by more than half. Turn it off, and the scores more than double.
Earl Britt reports: "Apple's virtual memory in 7.6.1 slows Illustrator to a crawl. It has taken as long as seven seconds just to select a menu bar item. Turning off VM speeds thing up." Earl found that switching to RAM Doubler 2 eliminated the problems. He had "file mapping only" enabled, but I believe other settings would have also worked.
b. Half minute startup slow-downs A few other readers report a half-minute delay at startup before the Mac even begins its startup routines, particularly at a cold start. There is a thread on this, specific to the Performa 6400, in Apple's Discussion Forums. The basic problem was described as: "The green light doesn't come on until (exactly) 28 seconds after the startup tone! Then the monitor turns on and the happy face comes on." Another user in this thread claimed that switching the Mac OS 7.6.1 System file back to a 7.6 version cured the problem.
Erick Abad, using an Apple Multiple Scan 15 monitor, wrote here at MacFixIt about having the same problem, additionally noting that it only began after installing the L2 Cache Reset extension.