Date: Fri, 22 Feb 2002 14:18:30 -0800 From: Terry Lambert <tlambert2@mindspring.com> To: "Frost, Stephen C" <stephen.c.frost@intel.com> Cc: "'freebsd-hackers@freebsd.org'" <freebsd-hackers@freebsd.org>, "'freebsd-questions@freebsd.org'" <freebsd-questions@freebsd.org> Subject: Re: PCI Probing Utility? Message-ID: <3C76C3B6.146FC817@mindspring.com> References: <B9ECACBD6885D5119ADC00508B68C1EA0288A6B3@orsmsx107.jf.intel.com>
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"Frost, Stephen C" wrote: > Oh FreeBSD Gurus... > > I tried throwing this out to the 'Questions' listserver and got zero reply. > So.... > > Is there some quick, down & dirty way of assessing the bus-speeds of PCI > slots/busses on a given box? I have a whole rack of systems with FreeBSD > 4.5 on 'em, and need to know the PCI bus configuration for each. > > Thank you in advance for your reply directly to this email account. There are a couple of ways: 1) Read the specs on the hardware 2) Transfer data on and off some card memory for a card known to be in the machine, and using the cycle counter and you knowledge of the clock rate from sysctl space to calculate it If you use the second method, you will be able to tell 32 bit 33Mhz and 64 bit 66Mhz, but you won't be able to tell between a 64 bit card in a 32 bit slot and a 32 bit card in a 64 bit slot. Very annoying. 8-). I recommend #1. A third method that would require driver hacks would be to do a series of small disk DMAs and time them for size and size *2 so that they fit entirely in disk cache. The DMA code isn't sufficiently instrumented for this, though. A fourth method, which may or may not exist, is to make a BIOS call and simply ask the hardware how fast it thinks it is... being as you're at Intel, you chould have the PCI technical documentation in your technical library. -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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