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Can't get a high FSB with your SL6Z3? Wierd solution.

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AudiMan

Member
Joined
Jan 16, 2002
Location
Winnipeg
I suggested my friend to get one of these 2.4C "MO" stepping CPU's, he installed it today and was only getting a stable 262 FSB. Needless to say, he was pretty upset considering he ordered from AZZO and paid the extra few bucks.

After fiddling with a bunch of settings, it was discovered that disabling "CPU Spread Spectrum" got him up to a stable 290 FSB MHz.

Meanwhile I'm running 280 FSB with "Spread Spectrum" Enabled on my 2.4C "MO" just fine, but when I disable it I get no Post.

He has the P4C800-E, and I have the P4C800.

Go figure,,

Anyone have a logical explanation for this?

(I have Corsair PC-3500 v1.1, 5:4, he is using Corsair PC-4000, 5:4)
 

TC

Senior Seti Addict
Joined
Jan 15, 2001
Location
Denver, CO
I've always heard to disable it for better overclocking results. Don't know why it caused a problem for you, but seems to make sense for him.
 

=ACID RAIN=

Member
Joined
May 19, 2003
Location
Kingwood, TX
It varies the actual speed of the system to lower EMI output, also known as electromagentic interference - IMO something we need not worry about. Imagine varying the speed of a system 25% (a common variation in spread spectrum settings):

Consider something along the lines of 11 x 200 =2200MHz. Vary the bus speed and you can go from 11 x 150 (-25%) = 1650, all the way to 11 x 250 (+25%) = 2750. Now think about the voltage for your processor being just enough to handle 2200MHz. See the problem? Even at momentary fluctuations, it's enough to make any overclocked system go to hell real fast.

This is the way I learned that spread spectrum works, correct me if I'm wrong....
 

=ACID RAIN=

Member
Joined
May 19, 2003
Location
Kingwood, TX
Actually, now that I think about it, it may vary speeds 12.5% from 200MHz in both directions instead of a full 25% both ways. Oh well, either way, you get the idea of what it does, and why it causes problems for overclockers!

It's early morning, I'm a bit slow right now...lol....
 

Thoth

Member
Joined
May 7, 2002
i am also stuck @ 262fsb... when i turn ON spread spectrum... no matter WHAT my board is set at.. it sets my cpu speed to default (2600)... anything above 262fsb hard locks the system ina few seconds after windows boots

i have an epox 4pca3+.. 3.4ghz is nice... but i was hoping for a lot more... i've ruled out the ram, cause my mushkin pc3500 will do 225 @ the timings i'm at now (209mhz)

i'm totally stumped :(

i'm seriously considering a new board...
 

shortbus_

Member
Joined
Nov 21, 2003
Location
CT
is this only on asus boards? what would it be called and where would it be found on my ic7?
 

daNo-

Member
Joined
Mar 25, 2003
What would this be called in an IS7-G :) im stuck around 260 fsb as well on my 2.4c m0
 

Flakk

Member
Joined
Nov 10, 2003
Location
Oregon, USA
im stuck at 270fsb

this trick didnt work for me unfortunately.. but im getting new ram and perhaps it will come in handy then.

see current system specs below