Xref: utzoo comp.sys.dec:1000 comp.periphs:1494
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!husc6!hscfvax!pavlov
From: pavlov@hscfvax.harvard.edu (G.Pavlov)
Newsgroups: comp.sys.dec,comp.periphs
Subject: Re: DEC RD52 alias Quantum Q540 Disk Drive
Keywords: Third-Party Disks Survey.
Message-ID: <715@hscfvax.harvard.edu>
Date: 29 Jan 89 21:54:49 GMT
References: <1394@cfa.cfa.harvard.EDU> <1290@ndmath.UUCP> <1044@uhnix1.uh.edu>
Organization: Health Sciences Computing Facility, Harvard University
Lines: 36

In article <1044@uhnix1.uh.edu>, rr@sun2.cs.uh.edu (Ravindran Ramachandran) writes:
> Hi, all. I am having an Ultrix cluster that consists of a 3200, and 2 2000's. 
> .... I am
> interested in purchasing some third party disks that are in the .5G to 1.2Giga
> range, and the price in the 7K to 14K range. My problem is that though the
> air-conditioning in the computer room is pretty stable, there is no special
> equipment, and so I cannot have a disk that dissipates too much heat......
> ... My disk has to be in a seperate enclosure, and I'm really not sure if I
> need another disk controller; I think I'm having a RQDX3 at the moment.
> 
  Re controller: yes, you should get a new controller.  Even if you could con-
  nect a high-performance disk up to the RQDX3, you would be wasting your mo-
  ney: you will gain the capacity of the additional disk but will not see any
  of its performance potential.

  There are good controllers on the market, including Dilog and Webster.  One
  MAJOR word of caution: MAKE SURE that the particular controller model that
  is suggested to you (or you choose) is actually designed for the MicroVAX
  3xxx series.  Lots of systems integrators have been selling controller 
  cards designed for the uVAX II into uVAX 3xxx systems.  Avoid this, because
  these configurations do not meet RFI and grounding requirements.  I know
  that Aviv has properly configured controllers and Dilog was developing one;
  I don't know about Webster.

  Re heat generation:  I assume that a high-density 5 1/4" drive will generate
  apx. 1 to 1.5 kw heat (the only such drives that we have came without heat
  generation specs; I'm guessing; anyone else know for sure ?).  If I am right
  then one or two such drives should not seriously hamper your air conditioning
  system, unless it was very marginal to begin with.

  One more thing about controllers:  the third-party controllers I have worked
  with gave great performance with one drive.  We use one controller per drive:
  for us, its still much cheaper than, say, a kda50, but in multi-drive configs,
  a kda50 will outperform the third-party controllers that we have used.

  greg pavlov, fstrf, amherst, ny