Date: Thu, 16 May 1996 11:27:35 -0700 (MST) From: Terry Lambert <terry@lambert.org> To: narvi@haldjas.folklore.ee (Narvi) Cc: terry@lambert.org, babkin@hq.icb.chel.su, hackers@FreeBSD.org Subject: Re: EDO & Memory latency Message-ID: <199605161827.LAA17550@phaeton.artisoft.com> In-Reply-To: <Pine.BSF.3.91.960516212452.25743G-100000@haldjas.folklore.ee> from "Narvi" at May 16, 96 09:28:15 pm
next in thread | previous in thread | raw e-mail | index | archive | help
> > > 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? Was this supposed to be a memory bus or a data bus speed? PCI can't run faster than 33 -- on a 75, that means 25. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199605161827.LAA17550>