From owner-freebsd-questions Fri Apr 21 3:58:41 2000 Delivered-To: freebsd-questions@freebsd.org Received: from Wheel.TSR.Ru (wheel.tsr.ru [195.208.67.7]) by hub.freebsd.org (Postfix) with ESMTP id 033F937B707 for ; Fri, 21 Apr 2000 03:58:30 -0700 (PDT) (envelope-from matrix@chat.ru) Received: from wp1 (CORE-30.dialup.tsr.ru [195.208.67.222]) by Wheel.TSR.Ru (8.10.1may/TELECORE-1.1) with SMTP id e3LAwJf14076 for ; Fri, 21 Apr 2000 14:58:22 +0400 (MSD) envelope from matrix@chat.ru Message-ID: <003601bfab80$82823c40$0c00a8c0@ipform.ru> From: "Artem Koutchine" To: Subject: SCSI vs UDMA IDE 32-bit Date: Fri, 21 Apr 2000 14:58:15 +0400 Organization: IP Form MIME-Version: 1.0 Content-Type: text/plain; charset="koi8-r" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2615.200 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2615.200 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG I've made a little test. I took a bunch of files (~130 MB) and copied them from one filessystem to another. The HDD is IDE Quantum FB 10GB. While copying i run top and saw about 80% of cpu wasted on interupts. Then i anables 32bit access for the hdd and turned on DMA transfers. Repeated the test and saw only tiny 0.8% wasted on interupts, which is comparable to what SCSI takes. So, knowing that SCSI and IDE hdd are based on the same mechanical parts why should even use SCSI? Am I missing something? Artem To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message