Date: Fri, 31 Dec 1999 09:32:27 -0800 From: R Joseph Wright <rjoseph@nwlink.com> To: "Norman C. Rice" <nrice@emu.sourcee.com>, freebsd-questions@FreeBSD.org Subject: Re: some performance issues Message-ID: <386CE8AB.29A140B5@nwlink.com> References: <386C023E.680FC31@inna.net> <386C0676.F39EC477@3-cities.com> <386C2354.ABD1ED54@nwlink.com> <386C3173.1D695393@3-cities.com> <386C543D.6E59C9DF@nwlink.com> <19991231104441.C2609@emu.sourcee.com>
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"Norman C. Rice" wrote: > > On Thu, Dec 30, 1999 at 10:59:09PM -0800, R Joseph Wright wrote: > > > > > > > > The 0x2000 allows IDE DMA transfers and that could be part of your > > > problem. Some drives like that setting and some systems don't. It is > > > something that you can try by seting it at boot time. If it works, > > > then you build it into your kernel. My drives are all 0xa0ffa0ff. > > > 8+2=a. > > > > Where did the 8+2 come from? This is really confusing to me. Do you > > mean that you get both 2000 and 80ff at the same time by using a? > > Thanks in advance, Joseph <):-{> > > Binary Decimal Hexadecimal > 0000 0 0 > 0001 1 1 > 0010 2 2 > 0011 3 3 > 0100 4 4 > 0101 5 5 > 0110 6 6 > 0111 7 7 > 1000 8 8 > 1001 9 9 > 1010 10 A > 1011 11 B > 1100 12 C > 1101 13 D > 1110 14 E > 1111 15 F > > 8 + 2 = Decimal 10 or Hexadecimal A > > In binary, > > 1000 (8) > +0010 (2) > ---- > 1010 (decimal 10, hexadecimal A) > > Using the 'a' instead of the '8' enables both of the following > features rather than just the 32 bit transfer capability. > > 0x8000 Test and use the 32bit transfer capability of the drive. > > 0x2000 Probe for and use the bus-mastering DMA capabilities of > modern PCI chipsets. That's making some sense. Now, what does the ff in 0xa0ff stand for? Happy Millenium :-] Joseph > -- > Regards, > Norman C. Rice, Jr. -- You will do foolish things, but do them with enthusiasm. Colette. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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