Date: Sat, 27 Dec 1997 08:35:21 +0800 (WST) From: Terry Dwyer 61 8 9491 5161 <tdwyer@io.telstra.com.au> To: Burton Sampley <bsampley@best.com> Cc: hardware@freefall.FreeBSD.org Subject: Re: NCR810 (or 875) & Asus P55T2P4 & Overclocking ? Message-ID: <Pine.BSF.3.91.971227080928.3471A-100000@io.telecom.com.au> In-Reply-To: <Pine.BSF.3.96.971226110223.23122C-100000@shell9.ba.best.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Fri, 26 Dec 1997, Burton Sampley wrote:
> Greetings,
>
> I've purchased the NCR810 controller, but I've noticed some strange things
> while running my system at the 83MHz (3.0X, 83Mhz = 250) bus speed. Make
[...]
>
> Here's dmesg:
>
> FreeBSD 2.2.5-RELEASE #0: Tue Oct 21 14:33:00 GMT 1997
> jkh@time.cdrom.com:/usr/src/sys/compile/GENERIC
> CPU: Pentium (250.57-MHz 586-class CPU)
> Origin = "GenuineIntel" Id = 0x543 Stepping=3
> Features=0x8001bf<FPU,VME,DE,PSE,TSC,MSR,MCE,CX8>
[...]
I take it you have a P200MMX. A friend of mine had similar problems with
his machine using the same settings as you've used. He reduced the
processor multiplier to 2.5, ( I know, it seems like a retrograde step),
leaving the bus at 83 MHz and is now running without problems.
He says although the processor is only running at 210 MHz now, the whole
system seems faster, better than 3 & 75MHz. Memory read/writes are
considerable quicker and disk i/o is marginally faster, I suppose it
depends on whether you need more processor (3.0 & 75Mhz) or better device
i/o (2.5 & 83 MHz). He only runs Win95 but he's done some benchmarks for
the two settings (3 & 75, 2.5 & 83)
I always thought the P166MMX was better value than the P200MMX. I haven't
seen a P166MMX That couldn't be bus overclocked to 83 MHz yet. I just bus
overclocked my son's new P166MMX to 83 MHz when I bought it for him just
before Christmas. Most people I know with P200's have not been able to
bus overclock them to 83MHz at the 3X processor multiplier. 8-(
I'd be surprised if it's your memory that's the problem, I only have 70ns
Fast Page RAM in my FreeBSD box (P133 Classic ASUS Rev 3.0 M/B) and I'm
using default BIOS settings at 83MHz - now a P166 8-). I've bus
overclocked a lot of ASUS M/B machines with varying types of RAM and,
(excepting P200MMX's) haven't found one I couldn't run with an 83MHz bus,
provided peripherals like early BIOS revisions of Adaptec PCI SCSI
controllers (before BIOS ver 1.21) didn't prevent it.
Oh yes, check your PB cache module if you have one. Make sure it's fast
enough to run at 83MHz or remove it. I think the module needs to be at
least the same speed as any embedded on the M/B (8ns IIRC) otherwise it
will only run at 75 with the normal 15ns PB cache.
Good luck.
_-_|\ Terry Dwyer E-Mail Work: tdwyer@io.telecom.com.au
/ \ System Administrator Private: tdwyer@omen.com.au
*_.^\_/ Telstra Corporation Phone: +61 8 9491 5161 Fax: +61 8 9221 2631
v Perth Western Australia (I do not speak for Telstra or Telecom)
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.BSF.3.91.971227080928.3471A-100000>