Date: Mon, 26 Jan 1998 19:43:03 +0100 From: Ollivier Robert <roberto@keltia.freenix.fr> To: freebsd-current@FreeBSD.ORG Cc: Manuel Bouyer <bouyer@chassiron.ensta.fr> Subject: Re: AMD k6 and > 32Mb RAM Message-ID: <19980126194303.27534@keltia.freenix.fr> In-Reply-To: <199801261707.SAA07023@chassiron.ensta.fr>; from Manuel Bouyer on Mon, Jan 26, 1998 at 06:07:49PM %2B0100 References: <199801261707.SAA07023@chassiron.ensta.fr>
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Manuel Bouyer disait : > there was a silicon bug in the earlier K6 that would make it not manage > properly the RAM, but I don't know if it has been fixed. No, the bug was -- it is fixed since rev. 9731 -- that when: - you have more than 32 MB of RAM, - the CPU tries to execute an instruction with memory operands separated exactly by 32 MB, In that situation, the CPU -- don't forget that it has a RISC core that translate Intel instr. into RISC ones -- thinks it is trying to translate a self-modifying instr. and execute the instruction twice. The result is sig10 or sig11 about 1/3 of the time during "make world" or an egcs compile. If you have a K6 with a rev. # less than 9731, send a mail to "euro.tech@amd.com" (if you're in Europe) and they'll change it very quickly. I don't have the address in the US but it is on www.amd.com. I sent back my K6-166 (rev. # 9725) to them (in UK) on Jan. 17th and got a K6-200 (rev. # 9745) on Jan. 21st. It has done several "make world" and pgcc compiles without a problem running at 3x 75 MHz (3x 83 MHz didn't work unfortunately). Copyright (c) 1992-1998 FreeBSD Inc. Copyright (c) 1982, 1986, 1989, 1991, 1993 The Regents of the University of California. All rights reserved. FreeBSD 3.0-CURRENT #53: Sun Jan 25 18:55:28 CET 1998 roberto@keltia.freenix.fr:/src/src/sys/compile/KELTIA CPU: AMD-K6tm w/ multimedia extensions (225.51-MHz 586-class CPU) Origin = "AuthenticAMD" Id = 0x562 Stepping=2 Features=0x8001bf<FPU,VME,DE,PSE,TSC,MSR,MCE,CX8,MMX> -- Ollivier ROBERT -=- FreeBSD: The Power to Serve! -=- roberto@keltia.freenix.fr Usenet Canal Historique
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