Path: utzoo!attcan!uunet!decwrl!ucbvax!tut.cis.ohio-state.edu!dinghy.cis.ohio-state.edu!pitonyak From: pitonyak@dinghy.cis.ohio-state.edu (Andrew Pitonyak) Newsgroups: comp.sys.ibm.pc Subject: Re: Whis is fastest 386/33 or 486/25 ? Message-ID: <82089@tut.cis.ohio-state.edu> Date: 12 Jul 90 19:49:01 GMT References: <1990Jul11.161138.13630@dvinci.usask.ca> <217@news.nd.edu> Sender: news@tut.cis.ohio-state.edu Reply-To: Andrew Pitonyak Distribution: na Organization: Ohio State University Computer and Information Science Lines: 17 >There would be no difference in speed between a 386 with a math >coprocessor and a 486. The 486 chip is a 386 + the math coprocessor in >one. Intel considers the 486 as a part of the 386 family. Not entirely true. The 486 does floating point much faster than the 386 because the FPU is on the chip. When the 386 does a 387 instruction it has to deal with the interface between the two chips, the 486 does not so it is faster with these instructions. By the way, the previously posted timings reflect this. You could improve things a bit by dropping in say a Cyrix chip rather than an intel chip with the 386 machine. I don't know if they have cleaned up and improved the other instructions. I do know that the 33Mhz 386/387 pair is more efficient than the 25Mhz 386/387 combination. Most unusual if you ask me. Andy