klliou@maven.u.washington.edu (06/16/90)
I have just increased 2 MB memory for my AT. I want to use it for cache and ram disk. Of course I hope it can be used fully. How much of it should be assigned to cache? or ram disk? Is there any PD tool that can be used to test the performance for different combinations? Any help will be appeciated.
dmurdoch@watstat.uwaterloo.ca (Duncan Murdoch) (06/16/90)
In article <13910.2678b7ff@maven.u.washington.edu> klliou@maven.u.washington.edu writes: >I have just increased 2 MB memory for my AT. I want to use it for cache and >ram disk. Of course I hope it can be used fully. How much of it should be >assigned to cache? or ram disk? Is there any PD tool that can be used to >test the performance for different combinations? > >Any help will be appeciated. I've found a cache more useful than a ramdisk. A ramdisk is most useful when you want fast writes as well as reads (most caches let writes pass through, for safety), but in my experience, temporary files that I'd like to put on a ramdisk soon grow too large, and I end up with them on a real disk anyways. If I had your 2 MB, I'd put 1 meg as a cache, and configure the other meg as expanded (EMS) memory. If you don't have any programs that know about EMS, you might consider a 1 MB ramdisk, but I think you'll find it hard to make good use of it. BTW, if you want to monitor cache usage, I wrote a program called CACHEMON, available on Simtel20 as CACHEMON.ZIP, that will give a report of how many logical read and write requests there have been, and how many made it past the cache as physical read and write requests. With a 1 Meg cache, I typically see all but about 18% of read requests being satisfied from the cache. Duncan Murdoch
dmimi@uncecs.edu (Miriam Clifford) (06/16/90)
I use a very small RAM disk to put batch files on. I store them on the hard disk as a zip file (big enough to store without much waste space) and unzip them onto the RAM disk at boot time. I've tried larger RAM disks and found I didn't use them effectively. When I got more memory, I made the small RAM disk, and use the rest for cache and expanded.