Hi everyone!  I'm a newb to overclocking in general, but i've read a couple guides focusing on the q6600 and this thread for the ga-p35ds3r, which I am using together.  
 
Anyway...I just got this, (q6600-g0 + ds3r rev2.0 w/default bios) setup recently and wanted to go with a conservative OC of 3.0-3.2ghz. I've followed the recommendations on this thread and others for a safe OC. Everything looks good upon bootup which shows "3.0" in the post test, and in the BIOS, it reflects this as well....
However when I get to windows and run cpuz...The core speed and multiplier jump around wildly. It goes from showing 3.0ghz, 9x multi to 1.66 ghz 6x multi. ?!?    
 
It's not a momentary hiccup or anything. It can stay down in the 1.6's for about 10-15 seconds and jump back to 3.0ghz. What gives? FSB is 333 I believe (whatever is normal for hitting 3.0ghz). My vcore is just slightly under stock (I was told 3.0 can totally handle slight undervolt from stock), and my ram is set to 5-5-5-15, 800mhz 1:1 synchronous mode.  
 
Any ideas why this is happening?  Everything is stable and I don't get any crashes running normal windows apps/crysis/benchmarks. Thanks for the support!

 
 
you need to disable speedstep feature in bios. Your mother might call it Enhanced............. sth.  What is your temp and voltage at 3.0. have you tried it to 3.2? Mine is absolutely stable at 3.1. but i can not go beyond that.  let me know when you have a chance.

that is called Intel Speedstep Technology to save energy when not running any task or at idle by select a lower multiplier to get lower speed.
 
as you have said you havent got any crash so its fine.your overclock is stable so no worry about that.

Speed Step!
 
Try search or Google once in a while!
 
Disable C1E in your bios if it bothers you, but it is a power saving feature. When you run a CPU demanding task it will stay full blast. your CPU will likely last longer if you leave it enabled since it wont run as hot at idle with Speed step enabled.

Well, I guess I reinforced the newb status from this post. lol.  I have heard of speedstep, but I don't think it's labeled in the bios that way. Maybe CIE or something like that?  I thought maybe something in the BIOS was throttling it up and down, but wasn't sure what was causing it.
Also, is there a negative to giving too much cpu voltage besides extra heat? I know that too little causes instability.  
 
Thanks for the info!

As said :  speedstep jumps the multiplier from 9 to 6.  if you change the multiplier down to say : 8, with a 400 bus, it will still clock down to multiplier of 6.  You would jump from 3.2, to 2.4 GHz with speedstep enabled.  9x333, you would step from 3 GHz to 2 GHz.  
 
Saves power and heat, which means money.

Everything was said already but just to confirm it.
There are two settings in the BIOS Advanced Chipset Features page:
EIST and C1E Enhanced Halt State.
 
- EIST adjusts voltage as needed (can cause stability issues during overclocking tests for some strange reason). You want it disabled during overclocking because it will overvolt your chip causing extra heat during load and since you are likely operating already above VID at 3.0GHz it could cause permanent damage.
 
- C1E adjusts multiplier (6 during idling to 9 under load). This you don't really want to disable. It has no noticable effect on performance and also doesn't cause instability during overclocking.

yep!disable all of them.but if my rig can handle it i will keep it on.it will make the CPU last longer.because my high overclock Q6600 will crash with the fluctuation of the multiplier and voltage.

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