bolef%albedo.span@VLSI.JPL.NASA.GOV (10/27/87)
This is a response to Art Stine's query on disk controllers I've been using Sigma SDC-RQD11-SC's for a year with success. These are caching controllers (1 Mbyte cache) which handle two SMD drives of any variety. Sigma is at (714) 630-6553. They may not be as "hot" as the Andromeda, but the relationship between actual through-put on your CPU and the bells-'n'-whistles of the controller is a sometimes thing. The big advantage of Sigma is the price. I've gotten them for less than $1000 each from a local firm, R-Squared (Rick Pickett, 303 799-9292). Of course the Dilog's handle four drives, though they don't have on-board cache. don't forget the Dilog DQ-236, if your transfer rate is under 2.5 Mbyte/second, as it is for the 9720's. Also, Plessey makes a virtually identical controller to the DQ-236 (Rick Ramirez, 505 471-6360), if you want to get a little bidding war started. As you probably know, the subject of on-board controller cache is a controversial one. VMS has lots of file caching already, and getting data from this source is much faster than getting it from a controller's cache, since you avoid all the QIO overhead. The only possible advantage of controller cache comes if you open and close the same files frequently, since the VMS caches flush when a file is closed. If Jim Reynolds of Andromeda lays his "super-performance" trip on you, challenge him by asking for a unit to test against your an ordinary controller with your standard applications! Regards, Larry Bolef Arpa-Internet: BOLEF%ALBEDO@ames-io.arpa University of Colorado SPAN/Physnet/Hepnet: ALBEDO::BOLEF -or- 33839::BOLEF Campus Box 449 TEXnet: UTADNX::UTSPAN::ALBEDO::BOLEF Boulder, CO 80309 Telemail: [LBOLEF/NASA] NASAMAIL/USA (303) 492-8124 UUCP(forwarded to ALBEDO): bolef@cires.colorado.edu -------