Q9550 > How to achieve higher FSB with lower VCORE???

toon_mad

toon_mad

toon_mad

Soldato
Joined
8 Jan 2009
Posts
4,819
Location
North East
i have hit 4.2ghz pretty easily with most things on auto, whilst testing for my max fsb limit im able to hit 4.5ghz without too much effort. The problem is i can only run it sensibly at 4.2ghz, im having to set the vcore in the bios to 1.400v (cpu-z reports it in windows at 1.38v just outside the intel reccomended volts).

I think with everything setup on the other options correctly i could lower my vcore and get the higher fsb i know i can reach. Im not familiar with some of the options in here, if someone with more know how can help me that would be great.

Here are my settings in BIOS now (prime stable at 8 hours > idle 40c max 63c, havnt run it any longer yet):

MIT

RGB > AUTO
CPU Clock Ratio > 8x
Fine CPU Clock Ratio > +0.5
Frequency > 4.2GHZ

**** Clock Chip Control ****
CPU Host Control > Enabled
CPU Host Frequency > 495MHZ
PCI Express > 100MHZ
C.I.A.2 > Disabled

**** Advanced Clock Control ****
CPU Clock Drive 800mv
PCI Express Clock Drive > 900mv
CPU Clock Skew > 0ps
MCH Clock Skew > 0ps

**** DRAM Performance Control ****
Performance Enhance > Turbo
X.M.P > Disabled
MCH Frequency Latch > AUTO
SPD > 2.66D
Memory Frequency > 1320MHZ (8-8-8-24-2T)

**** Mother Board Voltage Control ****
CPU VCORE > 1.40000v
CPU Termination > 1.32V
CPU PLL > 1.6V
CPU Reference > AUTO
CPU Reference2 > AUTO
MCH Core > 1.400V
MCH Reference > AUTO
ICH I/O > 1.600V
DRAM Voltage > 1.660V
DRAM Termination > AUTO
CH-A DATA VREF > AUTO
CH-B DATA VREF > AUTO
CH-A Address VREF > AUTO
CH-B Address VREF > AUTO

Advanced BIOS Configurations

CIE > Enabled
C2/C2E State Support > Disabled
C4/C4E State Support > Disabled
EIST > Enabled

Im also using Bios F4 (the latest full stable one).

Thanks in advance for any help anyone can give me, im sure i can get the same/better overclock with less vcore, i just need to know what to change to do this.

Cheers!
 
Last edited:
You'd have to start hand tuning these:

CH-A DATA VREF > AUTO
CH-B DATA VREF > AUTO
CH-A Address VREF > AUTO
CH-B Address VREF > AUTO

Which is a nightmare - also keep an eye on the VTT and PLL which I notice is on Auto - too high a level here can degrade 45nm chips quite quickly. I think the guidelines here are 1.4 and 1.6 but personally wouldn't go over ~1.35 for the VTT.
 
yeah the auto's scare me!

thanks for the reply, i will have a look at getting some of those auto's setup i think, starting with the PLL and VTT Termination.

Cheers...

edit: i set [email protected] (default 1.5v) and Termination [email protected]

will see how these values fair up with stability by a quick hour run of prime95.

if i can reduce the vcore i know the board/cpu is capable of much higher fsb, at the moment im not going past the 1.4v though
 
Last edited:
thanks Rroff, so do you think i could get my vcore much lower with some hard tweaking? its what im hoping, and worth the extra work if so.
 
I doubt you'd get it much lower... with some hardcore VTT and GTLREF tuning you'd prolly get the vcore down about 0.02-0.0375v top.


EDIT: Does your board show what values are used for the GTLREF lanes when in auto? if it does - and its working proper in auto and not just setting lane 1 then its much easier to find the optimal values...
 
Last edited:
ok cheers, i know intel says my reccomended vid is between 0.85V – 1.3625V, im currently just outside of that (1.4v in bios, 1.38v in windows), im not sure if its worth the extra few mhz with the voltages im at. It seems a lot of volts with the overclock im at now compared to some others ive seen.

That link was bloody technical, some good info though ;)

Im gonna see how much lower i can get the vcore with the same fsb, adjust some of the settings ive left, auto settings are pretty crap :D

cheers mate
 
As you have discovered, once you get up into the 4Ghz+ it requires a mixture of voltage settings to reach stability and vcore is not the giver of everything.

As you can see from my sig, my q9650 sets at a reasonable vcore for 4.6Ghz.

And never trust auto settings for voltages as the tendancy is for your bios to give them too much and certain higher voltages can add to instability.

You will have to start playing around with your voltages and REF. There is no easy way of doing it and it's trial and error and keep detailed notes on your settings as to what works/doesn't.

It took me about 3 weeks of playing around to get 4.6Ghz for 1.4v (bios) and a max of 4.9Ghz for benchmarking (at 1.55v).

To begin with even 4.5Ghz needed about 1.5v or more but after playing around with other settings I got this down.

Every mobo and cpu is different as to what works for VTT/PLL and GTL. I tried copying other peoples settings which were proven to be stable for their similar systems and my system would refuse to boot quite often although some worked but weren't stable.

In my case my cpu hates high PLL and has to have VTT set less then vcore and likes lower than the default ratio for GTL refs.

I also had to play with CPU clock drive (1000ms) and CPU/MCH clock skew (+100) to get 8 hour prime stability.

There are some great threads on q9550/q9650 and EP45 mobos on extremesystems forums which is where I started. You may get lucky and copying somebody elses settings works first time.

I found the one which was the "most" stable for my rig and then tweaked from there. I must have about 20 pages of notes on the thing and almost gave up at one point but the satisfaction of getting a stable high overclock is worth it.

And one last tip, I found Gigabyte's overclocking software great for experimenting with what works/doesn't work without having to keep rebooting.
 
Last edited:
cheers greebo, thats a mint overclock you have, my motherboard/cpu is not limiting me, im reluctant to go any higher then i have until i find a way to get lower voltages.

also, is your 1.395v set at that in the bios or windows?

cheers
 
That's my windows reading which is what counts as it's always less than what's set in bios. I used to have a p35 board which would only give 1.3v in windows from 1.4v set in bios.:(

From memory once I go above 512 FSB (which would give you 4.35Ghz with your cpu) it starts getting difficult and from memory I had to put loads more volts on the MCH and play with the MCH ref to keep any kind of stability on the fsb. I also think I upped the CPU termination but I will have to check my notes tonight as that was 4 months ago now!

TBH I can't even remember my settings now for 4.6Ghz :o

EDIT: One last thing to ruin your day, you can have your cpu set at a particular speed, play around with all the voltages and REF's and get them the best for your system and have full stability and then as soon as you aim for a different cpu speed, everything doesn't work for the cpu speed! If that makes any sense?

What I found was that it's best to start with your target cpu speed even if it means your vcore is too high to begin with (so long as temps are fine, in the short term it isn't going to do any harm) and then get the rest of your settings right for that speed which enables you to drop your vcore and keep stability.
 
Last edited:
Interesting thread this. I've been thinking of changing my old P35 mobo for a P45 as I can't get past 3.8ghz with my Q9550 E0. I'm sure it's the mobo that's holding me back as I get 3.8ghz with about 1.25v.

If I can't get a second hand one I was thinking of either the P5Q Pro Turbo (£92) or the EP-45 Extreme (£109) like you have toon, what do you guys think? Any others to look for, I can't find the UD3P in stock and the P5Q deluxe is a little more than I was planning to spend?
 
ok thanks greebo and roff.

i checked out google for extreme systems and was reading abit on there, they suggested to someone else setting everything at stock, then raise the fsb each time until windows freezes etc.

This way might be good, see how far i can get before i need to change voltages, gtl ref, clock skews etc. So i might reset everything and try that, i have a good vid at stock its only 1.001v or something


wolvers, i would go with the gigabyte, ive had asus before but never has a board overclocked as good as the gigabyte - it also has dual bios which has saved me already when i screwed up, the backup bios copied itself to the main bios and repaired itself :)
 
Last edited:
I found I was held back by my mobo. My cpu was 2nd hand and I already knew it could do 4Ghz at less than stock volts and 4.2Ghz at only 1.2v yet had a max of only 3.99Ghz on my x38 board no matter what voltages or settings I used (fsb limit of 444 I found, 1mhz more and it wouldn't even boot)

That's what made me buy the UD3P to get the most out of my cpu.

I've seen a few UD3P crop up recently in MM but the Asus P5 boards are also known to be very good q9xxx overclockers and hit 500+ fsb.
 
IMO only way to really make use of GTLREF:

Set vcore and vtt to 1.4 (unless you want to chance it higher) - find out what clock speed is 1hour OCCT stable, then drop them back ~0.025v and see which cores fail:

If core 0 or 1 failes, increase DATA and ADDR A 1 step until they stop failing - make a note of this number and keep increasing until that core starts failing again - then set the nearest setting to exactly half way between them...

If core 2 or 3 failes do the same for the B set.

At best its only gonna get you either a couple 100 more MHz or a drop in minor drop in vcore/vtt.

Then you have to give it a longer stability test, maybe some passes on IBT... but at this point it should only require minor tweaking if any to get long term stability.
 
I would 2nd getting a gigabyte board - mine have been rock solid and good overclockers... both my P35 DS3R and n650i DS4 manage more than 500 FSB stable.

I've killed more than one asus board with overclocking... and not pushing it that hard either... their northbridge chipsets are pretty crap.
 
toon_mad said:
ok thanks greebo and roff.

i checked out google for extreme systems and was reading abit on there, they suggested to someone else setting everything at stock, then raise the fsb each time until windows freezes etc.

This way might be good, see how far i can get before i need to change voltages, gtl ref, clock skews etc. So i might reset everything and try that, i have a good vid at stock its only 1.001v or something


wolvers, i would go with the gigabyte, ive had asus before but never has a board overclocked as good as the gigabyte - it also has dual bios which has saved me already when i screwed up, the backup bios copied itself to the main bios and repaired itself :)
Click to expand...

As you have said, there's more than one way of skinning a cat ;)

Only problem is there are so many bios options and just changing one slightly can be the difference between stability or total failure. I know that if I up my CPU reference one notch my windows will freeze. Yet using the method you have described there, I could have played around with loads of other voltages for hours and increasing them un-necessarily when all that was needed was dropping my cpu ref by one notch.

And that dual bios is indeed a life saver as I discovered when I was trying to 5Ghz.;)

Personally I'd be tempted to try my lazy way. Find somebody who has posted with the same mobo and cpu, copy their settings. If not fully stable play around with ref's and skews. If that doesn't work try somebody elses. That was my method in the end although I did try the old fashioned fsb by 5mhz, check, alter, repeat method as well.

And I like the fact you can have loads of different bios settings saved as well.
 
Greebo said:
And that dual bios is indeed a life saver as I discovered when I was trying to 5Ghz.;)

Personally I'd be tempted to try my lazy way. Find somebody who has posted with the same mobo and cpu, copy their settings. If not fully stable play around with ref's and skews. If that doesn't work try somebody elses. That was my method in the end although I did try the old fashioned fsb by 5mhz, check, alter, repeat method as well.

And I like the fact you can have loads of different bios settings saved as well.
Click to expand...

5ghz > you power whore :D

im trying to find some templates now and try your methodology.

working everything up from stock is going to take ages, might do that as a plan B

ps, my old asus sli board died with basic overclocking too, ive been put off asus ever since.

edit: i have just flashed to the F5i beta bios, load optimised defaults, the only thing i have changed is PLL, VTT, MCH,ICH and DDR Volts - ive left vcore and everything else as it was, set ram to 8-8-8-24-2T, upped the fsb to 3.2ghz, gonna play some fifa and then do some stress testing for more stability checks. will increase little bits and pieces as i go along see what i can get too...
 
Last edited:
I never did acheive the 5ghz though. 4.935Ghz was my max from memory :(

I decided that 5ghz was a step too far for my cpu/mobo/ram combo.
 
Greebo said:
I already knew it could do 4Ghz at less than stock volts and 4.2Ghz at only 1.2v
Click to expand...

4.2GHz with 1.2v is pretty dam special Greebo, I've only seen one or two others on such a low voltage with that clock speed, and iirc was over at the xtemesystems forum. :)

Greebo said:
I've seen a few UD3P crop up recently in MM but the Asus P5 boards are also known to be very good q9xxx overclockers and hit 500+ fsb.
Click to expand...

Can only echo the above opinion, Gigabyte UD3P and ASUS P5's are about good as it gets for 45nm 775 CPU's, UD3P is a cracker with 4GB however I did find it was a tad flaky with 8GB. :confused:
 
Last edited:
Any of the gigabyte or asus p45's are a great choice for a 45nm quad, beginning to wish id kept my p5q dlx/q9550 combo, would have made a cracking second rig. Had a very easy 3.8ghz from it on little over stock volts.
 
You must log in or register to reply here.
Back
Top Bottom