Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!mips!apple!altos!altos86!rcollins From: rcollins@altos86.Altos.COM (Robert Collins) Newsgroups: comp.sys.ibm.pc.hardware Subject: Re: How much for a 487SX?!! Message-ID: <286@altos86.Altos.COM> Date: 2 May 91 15:19:00 GMT References: <1991Apr22.155803.8093@tandem.com> <1991Apr27.194311.15636@bronze.ucs.indiana.edu> Reply-To: rcollins@altos86.UUCP (Robert Collins) Organization: Altos Computer Systems, San Jose, CA Lines: 49 In article ajai@sce.carleton.ca (Ajai Sehgal) writes: >I got some info from a friend @ Intel on this one, although it seemd a bit >strange. The 486SX uses the same mask as the 486DX with the coprocessor >connection traces cut. I don't know about the pinout but one would assume that >Intel wouldn't make the DX and SX pin compatable. The suggested list price >for a 486SX and a 487SX combined is not less expensive than the cost of a >486DX. One has to ask, why would anyone who wants an FPU buy the SX version? >You get the same thing with the added overhead of interchip communication. This is only the third time I will post this, so sorry if I sound a bit frustrated. At the present time, the '486SX, '487SX, and '486DX are all from the same mask. In the '486SX, the FPU is disabled. Both the 486SX and 487SX have different pin outs with respect to each other, and the DX. So none of them are pin compatible with each other. Intel has distributed schematics for a motherboard based on the 486SX/487DX combination. When the 487SX is installed in the system, it is connected in a way that quite literally disables the 486SX. In other words, you have an expensive chunk of silicon doing nothings. In fact, when you have the '487SX installed you can remove the '486SX. In the future, Intel plans to reduce the mask to remove the FPU from the '486SX to get the cost down. Why would Intel do this? Why would the 486SX/487SX combination be more expensive that the DX? Why would the make them all pin incompatible with each other? They have $$$ in their eyes. The market is supposed to perceive the '487SX as a coprocessor. A coprocessor can obtain a much higher profit margin than a CPU. So, Intel is trying to push the '487SX as a coprocessor to the '486SX, when it really isn't a coprocessor. It's simply a '486DX in a different skin. But as a coprocessor, it can afford a higher market price than a CPU. (Remember, the '487SX electronically disables the '486SX when both are installed.) Why are they all pin incompatible? To keep the whiz kids from putting in a DX, upping the crystal, and having a 33Mhz '486 at a much cheaper cost. $$$ $$$ and more $$$. This is all a brainchild of marketing people. Even many of the engineers at Intel think it is a stupid idea, and deplore the deceptive marketing technique. The same holds true for many of the field representatives, they think it is a sleazy marketing practice. But, rest assured, if you have a '487SX, you have all of the benefits of having the FPU on the same mask of silicon as the CPU, because it is nothing more than a repinned '486DX. -- "Worship the Lord your God, and serve him only." Mat. 4:10 Robert Collins UUCP: ...!sun!altos86!rcollins HOME: (408) 225-8002 WORK: (408) 432-6200 x4356