On Wednesday 06 March 2002 01:34 pm, Gerald Waugh wrote:
> This thing is running quite well and seems real snappy running X
> Now I want to know about fine-tunning it.
> What are people using for overclocking?
I've got a 1.4 Tbird runnin at 1.55 on a Soyo k7vta pro, almost a
year now. Multiplier == 11.5 X FSB == 135mz , Vcore == 1.85 ,
IOv == 3.44. None of this would be possible without high volume case
ventilation. Use a standard (ie, 'el cheapo', $8) heatsink/fan, but
scrape off the thermal pad and use thermal grease instead. Nothin
fancy, $2 Radio Shack compound will do nicely. Don't fall for the Artic
Silver with a $50 hs/fan hype, but you must move lot'sa air in/out of
your case. This is good practice even if you don't oc.
> and what CPU Freq Multiplier?
I'm assuming you realize that your XP is locked and that the L1
bridges must be closed to facilitate changing the multiplier. If you
don't want to risk closing the L1's, then at least keep the FSB
reasonable (see below).
There's two schools of oc'ing (IMO, and this applies mostly to AMD
133mhz (266) FSB, unlocked cpu's)
o kiddies ~ think that oc'g the FSB way over spec makes everything
oc'd. It doesn't. Problem is that this also raises the PCI (and thereby
AGP) bus too high. This causes large problems (sooner or _later_) for
PCI and AGP devices, specially harddrives and scsi devices. It does
soup up the ram tho**.
o old fuddy duddy's (like me ;) ~ keep their FSB close, but raise
the multiplier as high as it'll go**, then raise the FSB a touch.
Believing the PCI bus should be kept as close to 33.3mhz as possible,
this dictates that the FSB must be kept < 140mhz, which keeps the PCI
bus < 36mhz. The PCI bus should never exceed the range 30 to 36mhz.
Divide the FSB by 4 to obtain your PCI bus speed (by 3 for 100mhz FSB
cpu's).
** Stabilitiy ~ it ain't properly oc'd if it's not stable, as in
bulletproof. For instance my 1.4 will boot and run both Linux and
Winblows at 12x 137 (1.64 ghz), but it's not completely bulletproof
running the tests below (all have both Linux and Windoze versions)
o First, have a 'memtest86' floppy, and boot oc'd from it. Once
you've found the highest multiplier (FSB at the default 133mhz) you can
pass all the tests with, then
o Second, d/l Prime95 for Linux (mprime). Run 'mprime -m' and choose
number 17, the torture test. You must be able to complete all of the
test without errors. (This is where my Tbird at 1.64 fails, most likely
ram errors since I'm still usin ancient pc100 SDram, 35% oc'd)
o Third, and probly most important. Install lm_sensors and a GUI
(Gkrellm) to constantly display cpu temp. D/l and run Cpuburn's
'burnK7'. If you can leave burnK7 running for several hours, no errors,
and keep cpu temp <= 55�C, you're doin great. 60�C is tolerable, but
over time (dust bunnies and cpu creep), it won't be good enough. Keep
in mind that you're seein temps from a thermistor (probe), and that
actual core temp is probly 10, more likely 20�C higher. Since AMD specs
Athlons to fry at ~90�C, anything over 60�C from lm_sensors is
intolerable. Shut down the system, and study up on cpu/case cooling.
IMNSHO, the above tests should be run on non-oc'd systems also. Most
store bought, ready made systems would fail miserably with cpuburn.
Fine tuning: Raise the FSB (reasonably) and repeat all the tests
above. When you find the highest FSB that passes muster, back off 1 or
2 mhz. EG, my system is bulletproof at 11.5x137, but I run it at
11.5x135. Then try all of the above again with your ram bios settings
set to optimum. Most likey that'll be Cas2, 4 bank interleaving.
> And do I want to fool with the cpu volts?
Yes, check the spec for your cpu, but for mine it's a range that
AMD recommends, 1.7 to 1.85 Vcore. Higher is better, as it is for IOv
also. IO default is 3.3v, but up to 3.7 will provide better ram
stability and performance. IOv on my board's not adjustable, but most
good boards provide 3.4 to 3.5 by default. Kiddies might up the Vcore
into the near 2.0v range, but old fuddy duddy's like me stay within
reason (1.85 max).
You should see a linear improvement in CPUmark99 scores. IE, since
my 1.4 is ~11% oc'd, I see a 11% increase in CPUmarks. Cpumark is a
Winblows test, but it runs equally well under Linux with wine. Video
card performance should also scale linearly with cpu oc.
--
Tom Brinkman Corpus Christi, Texas
Want to buy your Pack or Services from MandrakeSoft?
Go to http://www.mandrakestore.com
