From owner-freebsd-hackers Thu May 16 11:23:52 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id LAA21952 for hackers-outgoing; Thu, 16 May 1996 11:23:52 -0700 (PDT) Received: from haldjas.folklore.ee (Haldjas.folklore.ee [193.40.6.121]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id LAA21947 for ; Thu, 16 May 1996 11:23:41 -0700 (PDT) Received: (from narvi@localhost) by haldjas.folklore.ee (8.6.12/8.6.12) id VAA28140; Thu, 16 May 1996 21:28:16 +0300 Date: Thu, 16 May 1996 21:28:15 +0300 (EET DST) From: Narvi To: Terry Lambert cc: "Serge A. Babkin" , hackers@FreeBSD.org Subject: Re: EDO & Memory latency In-Reply-To: <199605161709.KAA17364@phaeton.artisoft.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-hackers@FreeBSD.org X-Loop: FreeBSD.org Precedence: bulk On Thu, 16 May 1996, Terry Lambert wrote: > > I have just tried lmbench and the numbers it gives are looking > > slightly strange for me. It shows memory latency upto 500ns while > > I have 60-ns EDO memory in a Pentium/75 box. Okay, its external > > clock is 25MHz, this gives 40ns, one wait state, it gives another 40ns, > > it gives 80ns, but why the overhead is over 400ns ? > > 25 * 3 = 75 > > Multiply access latency by 3. Contrary to what some prefer to think, Pentium 75 run on the external speed of 50 Mhz - 1.5*50=75. So how about looking the figures over once more time? > > Then multiply the whole deal by 100/60 because you probably didn't > set HZ to 100. > > > Terry Lambert > terry@lambert.org > --- > Any opinions in this posting are my own and not those of my present > or previous employers. > Sander .sigless on the moment