Speedstep and default multiplier

mwalt2

Member
May 1, 2004
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Does the multiplier for a Q6600 have to be set at 9 for speedstep to function correctly? If I try to run at 8x400, Windows gives a BSOD or locks up while booting. If I change it to 9x356, everything loads fine and speedstep works. I suppose this means speedstep only works with the default multiplier, but I thought I'd ask (and searching for speedstep and multiplier returned mostly explanations of what speedstep does :)). Thanks.
 

Idontcare

Elite Member
Oct 10, 1999
21,110
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The short answer from experience is that no, you do not have to keep the multiplier at "stock" in order for speedstep to knock it down to "6" when your system is idle.

At least that is what I noticed on DS3L mobo and on P5E WS Pro mobo.

Now the voltage reduction on idle does stop working if you change the voltage manually (again just reflecting my experience, may be a mobo limitation thing). If you adjust the Vcore in your Bios to anything but stock then it will stay at that voltage even as speedstep reduces the clock multiplier.

Edit: and to check this for your system you really should keep the FSB the same (356 in your case) and test with multiplier of 9 versus 8 and confirm speedstep still works when you go from 9 to 8.
 

Boyd117

Member
Nov 14, 2007
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I would disable speedstep, this way your VID wont jump back and fourth...also get better clocks with it off
 

Quiksilver

Diamond Member
Jul 3, 2005
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If it were up to me, I would turn off C1E and SpeedStep for benchmarking and stability checking purposes then after that re-enable them both for general usage, not to mention reap in the less heat and power draw benefits.
 

VirtualLarry

No Lifer
Aug 25, 2001
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Yes, there are some motherboards where if you use a non-default multi and speedstep, you will have problems. Some mobos use the full range of multis for speedstep, regardless of what the max multi you have set, so for example, it will attempt to run at 9x400, even when you have the multi set at 8x400. That's probably why you are crashing.
 

mwalt2

Member
May 1, 2004
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Thanks for the replies. I tried 8x356 and it booted up fine and speedstep worked, just like 9x356...so it doesn't seem to be just the multiplier. With C1E and speedstep off, my settings at 8x400 are stable in prime95 small fft's for 10 hours. I ran memtest86+ overnight (12 passes) at 8x400 and did not get any errors (with C1E and speedstep enabled, though not sure it does anything with memtest). I just can't figure out why Vista gives me a BSOD Stop Error or locks up when booting when speedstep is enabled at 8x400. I have an Abit IP35-pro with bios 14. I may try updating it to see if it helps, but I'm pretty much out of ideas other than running 9x356 to get it to work (I am interested in the power savings since I rarely shutdown my computer).
 

Idontcare

Elite Member
Oct 10, 1999
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Originally posted by: mwalt2
Thanks for the replies. I tried 8x356 and it booted up fine and speedstep worked, just like 9x356...so it doesn't seem to be just the multiplier. With C1E and speedstep off, my settings at 8x400 are stable in prime95 small fft's for 10 hours. I ran memtest86+ overnight (12 passes) at 8x400 and did not get any errors (with C1E and speedstep enabled, though not sure it does anything with memtest). I just can't figure out why Vista gives me a BSOD Stop Error or locks up when booting when speedstep is enabled at 8x400. I have an Abit IP35-pro with bios 14. I may try updating it to see if it helps, but I'm pretty much out of ideas other than running 9x356 to get it to work (I am interested in the power savings since I rarely shutdown my computer).

This may seem obvious, but if speedstep works OK at 8x356 and doesn't work OK at 8x400 then the next thing I would do is walk my FSB from 356 towards 400 (all at 8X) and find out just when and where the FSB reaches the point where speedstep stops working.

Then I'd treat it like any other OC instability issue and I'd figure out what component needs a voltage bump to make it stable before heading any higher.