Date: Fri, 8 Oct 1999 16:33:16 +0930 From: Greg Lehey <grog@lemis.com> To: Tom <tom@sdf.com> Cc: The Hermit Hacker <scrappy@hub.org>, freebsd-scsi@FreeBSD.ORG Subject: Re: DPT Controller options ... one question Message-ID: <19991008163316.E78191@freebie.lemis.com> In-Reply-To: <Pine.BSF.4.05.9910071936170.17882-100000@misery.sdf.com> References: <Pine.BSF.4.10.9910080106280.30583-100000@thelab.hub.org> <Pine.BSF.4.05.9910071936170.17882-100000@misery.sdf.com>
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On Thursday, 7 October 1999 at 19:39:50 -0700, Tom wrote: > > On Fri, 8 Oct 1999, The Hermit Hacker wrote: > >> >> Okay, thanks... >> >> If there are cache's on the DPT controllers, does the OS make use of >> that, or is it automagic and transparent to the OS? Just want to make >> sure I'm getting full use of these things... >> >> Thanks... > > The onboard cache is transparent to the host. Howerver, there are many > settings available for tuning it though. You can set things like delay > before writing, and maximum amount of cache that can be "dirty" before a > flush is forced. Regardless, DPT IV cards are optimized for random > access. My DPT IV card never benchmarked well, but on a mail server, it > always exceeded my expectations. The general consensus is that the DPT IV is a very poor performer. Mike Smith has just committed drivers for AMI and Mylex controllers, which work a little better. So far nobody has been overwhelmed by the performance of any of them. Greg -- See complete headers for address, home page and phone numbers finger grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
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