Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!cica!tut.cis.ohio-state.edu!zaphod.mps.ohio-state.edu!wuarchive!cec2!sek9424 From: sek9424@cec1.wustl.edu (Scott Eric Keller) Newsgroups: comp.sys.ibm.pc Subject: Souping up my 286/10Mhz Message-ID: <1990Mar12.040128.3975@cec1.wustl.edu> Date: 12 Mar 90 04:01:28 GMT Sender: news@cec2 (USENET News System) Reply-To: sek9424@cec2.wustl.edu (Scott Eric Keller) Organization: Washington University, St. Louis, MO Lines: 37 I am currently trying to determine what real differences there may be between 10Mhz and 12.5Mhz '286 machines. I currently have a Compuadd 286-10 using a 10Mhz '286 processor with 1 wait state and 100ns RAM. This machine produces a 9.7Mhz clock rate on both the Lanmark CPU test and the PC Tech Journal ATPERF performance test. Out of curiosity, I tried operating the machine with 0 wait states. After a few memory errors at power on, the machine will operate for several minutes at 12.7Mhz indicated by the Lanmark test. The ATPERF test still shows 9.7.(why?) Eventually this configuration locks up. This is really no surprise since the processor is more than 25% over speed. My questions are as follows..... 1) Can the 10Mhz '286 be replaced with a 12.5Mhz '286 more or less directly? Note that the only 2 crystals in the machine are one of the colorburst variety and another which says 12Mhz. I have reason to suspect that the 10 and 12.5 boards may be one and the same. 2) If the above is affirmative, will anything else have to change. (i.e. RAM, clock crystal, etc.) I believe 100ns RAM should be fast enough. 3) Is there a reason for the wait state other than keeping the processor happy? Or is it needed to slow down to keep the memory happy? What is it we are all 'waiting' for? I realize this may not work, but given the fact that a 30% increase in speed could theoretically be had for ~$60 for a new processor I would certainly consider it. I would appreciate any information you can offer. Scott -- Scott Keller (KA0WCH) - Permanent Undergrad - Dept. of Computer Science Wa$hington Univer$ity - St. Louis, Mo. USA Internet: sek9424@cec2.wustl.edu UUCP:ihnp4!wucec2!sek9424 (I think...) The opinions represented here are mine and mine alone, not Wa$h. U's.