From owner-freebsd-current Sun Jan 17 17:07:39 1999 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id RAA07413 for freebsd-current-outgoing; Sun, 17 Jan 1999 17:07:39 -0800 (PST) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from caladan.tdx.co.uk (caladan.tdx.co.uk [195.188.177.4]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id RAA07408 for ; Sun, 17 Jan 1999 17:07:36 -0800 (PST) (envelope-from kpielorz@tdx.co.uk) Received: from localhost (kpielorz@localhost) by caladan.tdx.co.uk (8.9.2/8.9.2) with ESMTP id BAA38295; Mon, 18 Jan 1999 01:07:16 GMT Date: Mon, 18 Jan 1999 01:07:16 +0000 (GMT) From: Karl Pielorz To: Bruce Evans cc: lcremean@tidalwave.net, current@FreeBSD.ORG Subject: Re: Problems with new IDE's & -current In-Reply-To: <199901172356.KAA05189@godzilla.zeta.org.au> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Mon, 18 Jan 1999, Bruce Evans wrote: > New models of IBM IDE drives are fast enough to consume a significant > fraction (perhaps > 100%) of PIO mode 4 bandwidth (16.6 MB/s). Don't > use them without DMA. Don't use them without UltraDMA (33.3 MB/s) if > you want full performance. I presume the last "don't" should have been a 'do', i.e. _do_ use them with UltraDMA if you want full performance...? Also, the controller their running off isn't _Any_ DMA capable, at a guess it's going to be PIO4 tops, in which case (and as EIDA/UltraDMA are mean't to be 'backwards' compatible) - does this point to a bug/problem with the wdc driver? (i.e. drive too fast = wdc interrupt timeouts?) -Kp To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message