Path: utzoo!attcan!uunet!timbuk!cs.umn.edu!uc!noc.MR.NET!msi.umn.edu!umeecs!umich!samsung!cs.utexas.edu!sun-barr!olivea!mintaka!bloom-beacon!eru!hagbard!sunic!mcsun!cernvax!chx400!ethz!visinfo
From: visinfo@ethz.UUCP (VISINFO c/o Sascha Schnapka)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: HardFrame Still the Best?
Message-ID: <6381@ethz.UUCP>
Date: 26 Oct 90 10:47:10 GMT
References: <9010172027.AA03829@hamlet.acc.uncg.edu> <90297.223722IO92257@MAINE.BITNET>
Reply-To: visinfo@ethz.UUCP
Organization: ETH Zuerich, Switzerland
Lines: 78

In article <90297.223722IO92257@MAINE.BITNET> IO92257@MAINE.BITNET writes:
>So, harddrive owners out there, is the HardFrame
>still the Fastest, Meanest, Best SCSI controller-
>without-any-cheezy-RAM out there?

This is a question I (as a former hardframe enthusiast) have heard
quit often in recent times. This is what I can tell you about it:

- Hardware: The Hardframe is still the only HD-Controller with an
  Adaptec AIC-6250 SCSI chip that is capable of doing 2.5Mb/sec
  without using synchronous transfer.
  This chip also has other advantages over the commonly used
  Western Digital : on-chip intelligent caches and stuff.
  These advantages show up on every drive I have ever tested, ranging
  from Seagate 50Mb to CDC 660Mb.
 + 1) the limiting factor for maximum sustained throughput is higher
  than on the WD (the latter having something like 1.5Mb).
 + 2) the chip apparently always does some read-ahead, which
  considerably increases overall reading-speed on cheap drives,
  namely Seagate St-277N-1, St-296N. All these drives run interleave
  1 on hardframe only. (Since I do no longer own such, I have not yet
  tested them on the latest GVP)
 + 3) You also get more performance with extremely expensive drives having
  internal caches. Namely the reading-speed for short files (important
  almost anytime, namely during execution of startup-sequence)
  is much higher with the HardFrame. The most extreme case I have ever
  seen was with a CDC Wren VI (660Mb), where the read transfer rate
  at a file size of only 4kb was about 300kb with 2091,2090 and even
  less with the former GVP version compared to over 800kb on a HardFrame.
 + 4) Some diskspeed tool I tested showed that the HardFrame also has
  a more powerful data path from the board into memory.
  The tool had an optional 'DMA contention' which turned on all bitplanes,
  copper and stuff. The HardFrame was the ONLY controller that did not
  show the slightest performance degradation at full load.
  
 - 5) You cannot use the HardFrame on the A3000 (as all DMA-HDControllers)
  because it does not DMA into the A3000's outside 24bit FAST RAM.
  Everything goes from/to Chipram and must then be copied from the
  Buffer to the location in FastRAM USING THE CPU.
  

- Software
  This is the weak point of the HardFrame.
  Although the HardFrame was kind of state-of-the-art when it came out
  and had some very clever features like built-in FileSystem.resource,
  the software Version 1.5 is not satisfying.
  To explain it quickly: WHEN your drive runs with HardFrame, usually
  everything is fine. But try to get a drive running on HardFrame
  that refuses to. (And that I have often experienced)
  Not only is the HardFrame kind of choosy and simply does not accept
  some strange drives (like Maxtor...) but the device driver is
  improper. It makes assumptions about the internal state of the drive,
  lacks timeout functions for bus signals and VERY OFTEN crashs
  when the drive does not behave the way HardFrame thinks.
  These deficiencies will HOPEFULLY be fixed in the new 1.9
  release Microbotics announced recently.
  But there are more disadvantages in the software:
  - Microbotics refuse to cooperate with Commoddore for UNIX drivers
    (This may have changed since I got this information at the last
    Ami Expo in Basel)
  - Microbotics are almost the only people not to support A-MAX.
  What reasons they have, I cannot understand.
  I even think someone like Ralph Babel should go and make a
  HardFrame.AMHD.

>HardFrame and the GVP II's and the Hardframe
>was said to be twice as fast as the GVP? 
 That was with the old, slow version of the GVP. This can no longer
 be claimed and either way depends on the drive you use.


Peter Simeon & F.Burgel, authors of 'HD-Tools' (available on BIX, FTP)

/* -------------------------- SG (Simeon Graphics) ---------------------- */
/* Peter Simeon,      UUCP: |       //                             //     */
/*  visinfo@bernina.ethz.ch |      //    Long live the AMIGA!     //      */
/* BIX:  hardwiz            |    \X/                            \X/       */
/* ---------------------------------------------------------------------- */