From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Russ Cox" To: 9fans@cse.psu.edu Subject: Re: [9fans] bochs still no go MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Message-Id: <20011211032545.43452199B5@mail.cse.psu.edu> Date: Mon, 10 Dec 2001 22:25:43 -0500 Topicbox-Message-UUID: 327c4de0-eaca-11e9-9e20-41e7f4b1d025 > If "RDMSR" is being used to read the time stamp counter, > it should be replaced with RDTSC (0x0F 0x31). RDMSR is > a much slower instruction. That's not at all clear. I bet they're approximately the same on real hardware. RDMSR is much slower under VMware because it requires trapping into the VMware runtime, while RDTSC, an unprivileged instruction, does not. Since Bochs isn't using the underlying machine to execute _any_ instructions natively, I would be hesitant to draw speed comparisons. Of course, it appears that RDMSR is unsupported, but that's different. We use RDMSR for things other than reading the time stamp counter, though. Russ