kvc@scgvaxd.UUCP (06/13/84)
Your best bet is to trade in your memory controllers for the new ones and buy more memory. We got quite a dramatic performance improvement out of a 750 (running VMS, but should make little difference) when we went from 2Mb to 5Mb. I realize the controller presents a problem, but if there is any way on earth you can afford to swap it for new ones, by all means do so. DEC will quite happily swap new memory for old on 780s, and will give you a trade-in discount on your old stuff. I'm sure they'll do the same for 750s. /Kevin Carosso allegra!scgvaxd!engvax!kvc Hughes Aircraft Co.
pete@edcaad.UUCP (Peter Sykes) (06/14/84)
We are running out of vax at the moment. Our small (but greedy) user population is complaining about response time and I am looking at upgrade paths. The relevant details are. Vax 11/750 2Mb (old controller therefore full). 2 Disks one on the unibus one on the massbus swapping on both and both resonably quick (< 30ms). We are running 4.1c bsd and the load factor at bad times is about 4. The applications are mainly interactive graphics, hence the response time is important though typically only 2-3 users out of 8 are using graphics. We also use Prolog coupled to a graphics manager. Vmstat reveals that idle time is frequently 0 for minutes at a time system time varies between 5% - 50%. pi and po are usually 0 but go up to 10-12 when loading large databases and the number of disk faults is also 10-12 Can anyone supply any clues as to what the most effective upgrade would be or what I can fiddle with to tune the system. One thing I have noticed is that system time goes up dramatically when we run prolog graphics and even more so with emacs (Up to 90%). The common factor is the use of multiplexed files. Are they known to be inefficient in 4.1c or can this be normal? Thanks in advance Pete Sykes vax135!ukc!edcaad!pete