From owner-freebsd-alpha Sun Jun 23 11: 1:56 2002 Delivered-To: freebsd-alpha@freebsd.org Received: from duke.cs.duke.edu (duke.cs.duke.edu [152.3.140.1]) by hub.freebsd.org (Postfix) with ESMTP id DB85337B407; Sun, 23 Jun 2002 11:01:41 -0700 (PDT) Received: from grasshopper.cs.duke.edu (grasshopper.cs.duke.edu [152.3.145.30]) by duke.cs.duke.edu (8.9.3/8.9.3) with ESMTP id OAA23338; Sun, 23 Jun 2002 14:01:41 -0400 (EDT) Received: (from gallatin@localhost) by grasshopper.cs.duke.edu (8.11.6/8.9.1) id g5NI1AE06755; Sun, 23 Jun 2002 14:01:10 -0400 (EDT) (envelope-from gallatin@cs.duke.edu) From: Andrew Gallatin MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <15638.3302.913567.234842@grasshopper.cs.duke.edu> Date: Sun, 23 Jun 2002 14:01:10 -0400 (EDT) To: Yoriaki FUJIMORI Cc: obrien@FreeBSD.ORG, freebsd-alpha@FreeBSD.ORG Subject: Re: What are my options PC164 and Symbios 53C895 In-Reply-To: <200206230755.g5N7t2N53755@prinz.fujimori.cache.waseda.ac.jp> References: <20020622231921.A22789@dragon.nuxi.com> <200206230755.g5N7t2N53755@prinz.fujimori.cache.waseda.ac.jp> X-Mailer: VM 6.75 under 21.1 (patch 12) "Channel Islands" XEmacs Lucid Sender: owner-freebsd-alpha@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org Yoriaki FUJIMORI writes: > One more comment. You cannot exploit the performance of LVD on 21164 > systems. (Not on entry level 21264 systems, either.) I did not measure > it precisely, but my feeling is the top speed of pci bus on 164LX is > still below 30MB/sec. Naturally, much worse on PC164. Its not quite that bad. For large tranfers, a 32-bit card should be able to do ~70MB/sec for DMA reads (write to disk/ send on network) and over 100MB/sec for DMA writes (read from disk, recv on network). Here is actual data from a 164SX, which is somewhat similar to the LX: DMA rate for 8192 Byte pages (32bit / 33MHz bus) Timing 32 pages. bus_read (send) = 72 MBytes/s bus_write (recv) = 126 MBytes/s I measured my UP1000 and it was also somewhere in the this neighborhood. 64-bit cards in tsunami based machines are quite a bit better, but still are nowhere near as good as most modern x86 (or even Apple) chipsets. Drew To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message