Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!husc6!hao!ames!ucbcad!ucbvax!BIOVAX.RUTGERS.EDU!hamm From: hamm@BIOVAX.RUTGERS.EDU Newsgroups: comp.os.vms Subject: Third UDA on VAX 785: is there any point? Message-ID: <8710232250.AA11233@ucbvax.Berkeley.EDU> Date: Thu, 22-Oct-87 17:48:00 EST Article-I.D.: ucbvax.8710232250.AA11233 Posted: Thu Oct 22 17:48:00 1987 Date-Received: Sun, 25-Oct-87 18:45:14 EST Sender: usenet@ucbvax.BERKELEY.EDU Reply-To: Organization: The ARPA Internet Lines: 31 Hi - I need some advice from a Unibus expert. I have a VAX 785 with two Unibus adaptors, two UDA50s, and five RA-81s. The number of disks can be expected to grow a little (say, up to eight) over the next year or so. Now I've been given an extra UDA50. The question is this: Is there any performance advantage in installing it and distributing the disk load across 3 UDAs instead of two? (For example, I might put the system disk all alone on one UDA.) This would put two UDAs (and nothing else) on one Unibus, and one UDA (and comm gear, and printer, and tape drive) on the other. Put another way, the question is: what is the limiting element for Unibus RA disk performance: the UDA50 or the Unibus? The main disadvantage I know about is the added maintenance fee - if you know any others, I'd appreciate hearing about them. Thanks, Greg ------------------------------------------------------------------------------ Greg H. Hamm || Phone: (201)932-4864 Director, Molecular Biology Computing Lab || Waksman Institute/NJ CABM || BITNET: hamm@biovax P.O. Box 759, Rutgers University || ARPA: hamm@biovax.rutgers.edu Piscataway, NJ 08854 * USA || ------------------------------------------------------------------------------ ------