Date: Fri, 31 Jan 1997 20:53:37 -0800 (PST) From: John-Mark Gurney <jmg@nike.efn.org> To: Terry Lambert <terry@lambert.org> Cc: hackers@freefall.freebsd.org Subject: Re: performance puzzler Message-ID: <Pine.NEB.3.95.970131204506.27974G-100000@hydrogen.nike.efn.org> In-Reply-To: <199701311738.KAA03009@phaeton.artisoft.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Fri, 31 Jan 1997, Terry Lambert wrote: > > The puzzling thing comes when I try to run the test at home on my AMD > > 486-120, running 2.1.0-RELEASE. It runs the test in 0.6 milliseconds!! > > Divide each clock speed by increasing integer values starting with 1 > until the result is less than or equal to 33. This is your max bus > speed possible for the system. An easy way to do this is magnitude > based arithmatic (yes, I own a slide-rule): > > exp(log(120)%log(33)) = 30 > exp(log(66)%log(33)) = 33 > > Your bus on the 120 is 3MHz slower than the bus on the 66. What you > are doing is not I/O bound, it is CPU bound. umm... this usually isn't true... most of the non 33mhz bus speeds (for 486 based chips) are actually 40 mhz or 50mhz... the amd-486/120dx4 is actually a 40mhz bus multiplied by 3... it's kinda like the Intel 486/100dx4... the chip is actually 3x bus speed (33mhz)... like AMD makes a 5x86/133... if you get the ADZ version you can usually over clock it to a 160... 40mhz x 4... the reason being is the ADZ's encasing is rated at 85C unlike the ADW that's only 55C... sure it's taking a chance, but it's a nice boost on a vlb based machine :)... John-Mark gurney_j@efn.org http://resnet.uoregon.edu/~gurney_j/ Modem/FAX: (541) 683-6954 (FreeBSD Box) Live in Peace, destroy Micro$oft, support free software, run FreeBSD (unix)
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.NEB.3.95.970131204506.27974G-100000>