Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!convex!woods From: woods@convex.com (Darrin Woods) Newsgroups: comp.sys.mac.hardware Subject: Re: SIMMs for IIsi - what do I need? Message-ID: <110992@convex.convex.com> Date: 13 Dec 90 15:19:02 GMT References: Sender: news@convex.com Organization: Convex Computer Corporation; Richardson, TX Lines: 28 In article es1o+@andrew.cmu.edu (Eric Mitchell Snider) writes: >I just bought a IIsi 40/2. I had the 1 meg of 256K SIMMs from the si >put into my Plus. I want to put my 4 megs of RAM from my Plus into the >IIsi. The memory from the Plus consists of two 70ns 1 meg SIMMs and two >100ns 1 meg SIMMs. Is there any problem with doing this? MacWorld says >"The machine requires 100 nanosecond RAM chips, but Apple is providing >80ns ones. Thus users who have the IIsi and IIci can swap SIMMs between >the two." So 100ns should be fast enough but is it ok to mix 2 70ns and >2 100ns? > 100ns chips work just fine - go tell the tech to go back to school. I don't know if I would recommend mixing the two. The si works in banks of 4 like the II, IIx, cx, ci SE/30 fx... All 4 SIMMS should be the same speed. It usually works just fine to mix speeds across two different banks, but Apple (and I) do not recommend mixing in a bank because of the way that the mac uses the SIMMS in the bank. One SIMM will be receiving (sorry, working with) info at 70ns and the other at 100ns, and it will probably cause problems. Blacksheep Senior Systems Engineer -- Darrin R. Woods woods@convex.com This is a guest account. Convex knows nothing about what I'm saying, or even that I'm saying it.