How to set up GTL Ref Values for 45nm & 65nm

[CryptiK]

No they don't need to be the same. Just start with 0.630x for both and see what works best. I think I used 0.667x for 0/2 and 0.690x for 1/3 when I was using my C0 E8400 on my P5Q Deluxe as it gave me the most stability.

[lordmagnum]

Once I set all GTLs on .630 I've not crashs anymore, playing TF2 for 2h, before, after about 5-10 min I got a crash. Tomorrow, I'll run some stability tests to check all of that.

[vodka3dg]

this thread is lifesaving
i first set a gtl then try min stable VTT..
if none then i try next gtl.

is this logic allright?
or should i try a different approach?

thanks a lot!

[KB24LA]

my p5q3 has only 4 gtl ref values - 0.615, 0.63, 0.65, 0.667
so where should i start?

[CryptiK]

this thread is lifesaving
i first set a gtl then try min stable VTT..
if none then i try next gtl.

is this logic allright?
or should i try a different approach?

thanks a lot!

Personally, I would set default Vtt for the p45 which from memory is 1.20v then play around with the GTL's from there.

my p5q3 has only 4 gtl ref values - 0.615, 0.63, 0.65, 0.667
so where should i start?

I'd start with 0.630x and go from there.

[scharnhorst]

Hello,

Could you tell me if a wrong setting for GTL might be dangerous for the motherboard or cpu?
I mean, using a wrong GTL's setting could be as destructive as a very high voltage?
Thank you very much for any help

[humeyboy]

Hello,

Could you tell me if a wrong setting for GTL might be dangerous for the motherboard or cpu?
I mean, using a wrong GTL's setting could be as destructive as a very high voltage?
Thank you very much for any help

Doubt it, it will simply fail in Stress Testing.

[Andren83]

Hi guys, i really need ur help otherwise i think im gonna crash this cpu on the floor

here the situation

i have a q9550 E0 (vid 1,2125) on a MIIF (bios 2104) and i wonder how i should tweak with these GTL settings. i have no clue even if i read everything in here... i know sounds im really stupid.

I have also the excel file of seban but dunno how to use it.

It's weird because even if i put high settings on vcc,vtt,pll,nb the system is not stable so someone told me the key is in the GTL values... i hope so but i cant find this bloody key



could u help me out??? pleaseeeeeeeee

[humeyboy]

Tell me the VTT (FSB Termination Voltage) you are ideally trying to currently run at.

[Andren83]

Tell me the VTT (FSB Termination Voltage) you are ideally trying to currently run at.

1,3v mate, and at the mom i'm trying this combo GTL (1/3) +40 GTL (0/2) +10

dont ask me where i find this settings... its just a random try

vcore 1,27
pll 1,59
nb 1,32
ram auto (should be no problem with them)

thanks for reply

[humeyboy]

GTL's should be 41 so set it to whatever is nearest that.

For Neg that could be -40 or -45, for Pos it will be +40 (as it is in 10's not 5's).

Just Set like this for now.

45nm Quad Core bellow:

CPU GTL REFERENCE (0) Auto
CPU GTL REFERENCE (1) -40mv
CPU GTL REFERENCE (2) Auto
CPU GTL REFERENCE (3) -40mv

Then try Pos if no good.

[Andren83]

GTL's should be 41 so set it to whatever is nearest that.

For Neg that could be -40 or -45, for Pos it will be +40 (as it is in 10's not 5's).

Just Set like this for now.

45nm Quad Core bellow:

CPU GTL REFERENCE (0) Auto
CPU GTL REFERENCE (1) -40mv
CPU GTL REFERENCE (2) Auto
CPU GTL REFERENCE (3) -40mv

Then try Pos if no good.

I'll give it a try dude and hoping can get better stability...

at the moment im passing 2hr SmallFtt with vcc 1,27 and Gtl +40+10+40+10
and NB Gtl +30

After i finish this test (it means as soon as it crash ) i'll do it yours as u suggested me and compare the results (so which one of Gtl sets is better)

Appreciate ur help mate

[humeyboy]

The GTL I gave you is due to your 1.3v it may not be any good as your 1.3v may not be the correct choice.

I found the NB GTL is more important after say 450FSB.

[Andren83]

The GTL I gave you is due to your 1.3v it may not be any good as your 1.3v may not be the correct choice.

I found the NB GTL is more important after say 450FSB.

Well, as i supposed, as i woke up i found my system crashed after about 9hr of SmallFtt so i think we are near to the correct Gtl set, at least i hope so

at the moment im over 450Fsb (471*8,5), do you think have i to set also NB Gtl or not then?

Now, to be sure, im doing, with yesterday settings, another try with +40+10+40+10 and Gtl Nb +30 but running Blend this time and see how far my system goes... i imagine it will not pass 10hr, or may be less...

after that i go on with these other two sets:

Auto/-40/Auto/-40 and +40/Auto/+40/Auto like u said humeyboy

EDIT: Blend resisted just 1hr and then my system reboot

[humeyboy]

Yes for that FSB you need NB GTL set correctly.

I cannot use Neg NB GTL at that speed, +40 seems good for me, but tried +20 & +30 & +40

See when you fail Small Prime its normally due to the CPU so you need more CPU VCore or VVT but if it fails a Large Prime or Blend Prime its the Mobo so you may need more NB or Memory Volts.

I would leave the Multi LOW and use higher Vcore than you think you need for the given MHZ till you find your MAX stable FSB.

[_AntLionBR_]

A question:

For example, I make the adjustments in the BIOS (VTT, NB, PCIE, DRAM, PLL, vCore CPU) for a given clock speed of the processor, but is missing only the adjustment of GTLs (remembering that the clock speed in which I put FSB + Mult) already agree to that clock, it only remains the configuration of GTLs in this case), but the system is unstable, where I get is: With a few simple adjustments in GTLs (this time) could the system is stable, moving only option in this case?

Sorry for my English, I hope you understand.

Thank you !

[zpower]

Hello to all,

I m trying to figure out what are my GTL Ref values for my system but i am missing something...

my Vtt is 1.31v

so,

1.31v x 0.667 + Y = 1.31v x 0.635
0.87377v + Y = 0.83185v
Y = 0.83185v - 0.87377v
Y = -0.041v
Y = -41 mv

This value refers to GTL Ref 1/3 or 0/2 ???
If it refers to 1/3 what i put to 0/2 and viceversa

By the way, i have an asus rampage extreme and a QX9770 (45nm)

Thanks in advance for any help given!

Alex

[sheri]

Hi,

Could anyone tell me how GTL 0/2, 1/3 and Nb GTL are named in EP45 DS5.

I've got:
-CPU Reference (0.63x def.)
-CPU Reference2 (0.66x def.)
-MCH Reference (NB reference- am I right?) (0.63x def.)

-MCH/Dram Reference (connected with ram termination, which i don't change)
-Dram Channel A & B reference (connected with ram termination, which i don't change)


I'm asking 'cause i'm playing with first three voltages and i can't gain stable 4Ghz with PDC E6300 on 400 FSB with x10 multiplier.

Thanks !

[95blackz26]

between this thread and looking through every ones over clock with similar configurations i have found a better combo of GTL's and everything seems more stable now.

definitely some good info here and i thank you for taking the time to share ti.

[CryptiK]

Hello to all,

I m trying to figure out what are my GTL Ref values for my system but i am missing something...

my Vtt is 1.31v

so,

1.31v x 0.667 + Y = 1.31v x 0.635
0.87377v + Y = 0.83185v
Y = 0.83185v - 0.87377v
Y = -0.041v
Y = -41 mv

This value refers to GTL Ref 1/3 or 0/2 ???
If it refers to 1/3 what i put to 0/2 and viceversa

By the way, i have an asus rampage extreme and a QX9770 (45nm)

Thanks in advance for any help given!

Alex

On for example the Maximus II Formula 0/2 is 0.635x by default and 1/3 is 0.667x by default. You have control over each, so 0/1/2/3 = 0.635x/0.667x/0.635x/0.667x

The -40mv would refer to the GTL Ref with 0.667x by default, so 1/3.

I'd assume is the same on the Rampage Extreme, although I cant be certain. That's the way I set them on my REX anyway with good results.

Hi,

Could anyone tell me how GTL 0/2, 1/3 and Nb GTL are named in EP45 DS5.

I've got:
-CPU Reference (0.63x def.)
-CPU Reference2 (0.66x def.)
-MCH Reference (NB reference- am I right?) (0.63x def.)

-MCH/Dram Reference (connected with ram termination, which i don't change)
-Dram Channel A & B reference (connected with ram termination, which i don't change)


I'm asking 'cause i'm playing with first three voltages and i can't gain stable 4Ghz with PDC E6300 on 400 FSB with x10 multiplier.

Thanks !

For your board, CPU 0/2 = CPU Ref 2 = 1/3, and MCH Ref = NB Ref.

between this thread and looking through every ones over clock with similar configurations i have found a better combo of GTL's and everything seems more stable now.

definitely some good info here and i thank you for taking the time to share ti.

Good to hear you made progress.

[Salty]

I just read the thread. Hours. You are probably entirely over the endless queries, but really hoping you can manage another? I am overclocking an e8500 in a GA-X48-DQ6, which does not have anywhere near the bios settings an Asus X48 or DFI X48 or EP45-UD3P has. It does have two GTLREF settings in MIT if Control + F1 are pressed in main bios screen.

I am running 9.5 x 466 with the idea that staying on multiples of 33.33R would be easier than "out of sequence" fsb numbers. I get the message here that is a mistake?

Should I also run 101-102 PCI instead of 100?

The adjustments for GTLREF_0 are: AUTO, +3%, NORMAL, -3%, -6%
The adjustments for GTLREF_1 are: NORMAL, -3%, -6%, -9%
(That's AFAICR)

I've got:


Over the last couple of months this OC started at 1.3875v cpu core, +.15 fsb overvolt (vtt), -3% for GTLREF_0, Normal for GTLREF_1, and +.225 MCH. I would get a bluescreen with heat or while booting, and unbootable till a setting is raised. Of course once vtt went up the GTLREFs changed too, but not what I expected. If I change REF1 down bluescreen, so only REF_0 changed.

From 1.3875v worked way up to 1.40625v. It plays games, runs OCCT and Prime for a few hours at least, sometimes 24, but then another random bluescreen. Debug sometimes says hardware, sometimes a windows driver.

Anyway I'm wondering if there are any suggestions for ending this cycle of bluescreens.

I can see maybe 467bclk and 102 pci?

[CryptiK]

Sure, although some boards seem to prefer multiples of 33.33 (from Mikeyakames findings) feel free to use whatever FSB takes your fancy.

I have not found raising PCI-E to change anything, but you can have a go, you might get lucky, I've not used that board so I can't say if it will affect anything or not.

Have you checked your ram stability? Could be the cause of your blue screens if your CPU is indeed stable. Perhaps also adjusting you GTL's may aid in possibly reducing your Vtt and perhaps vcore - have you tried setting them both to normal or +3%?

Also you have CPU/NB clock skews, pehaps try adjusting these - some boards respond to this even at <500 FSB. If it makes things worse or doesnt help you can just set to back to normal, and it wont break anything playing around with it.

Lastly, increasing CPU/pciex clock driving control to 900 - 1000mv can aid stability (certainly makes a big difference when OC'ing quads on the UD3 series), so it may be worth a try also.

[Salty]

You guys have helped a lot of overclockers with this thread

have you tried setting them both to normal or +3%?

Both on Normal worked up to 444. Probably changed with +.15 vtt raise. Then -3%/Normal was the best combo - passed 37 hours prime95 blend. Putting them both on the same since just bluescreens or fails prime faster. When I went to +.2 vtt the best setting proved to be -6%/Normal. Not what I expected.
-6%/-3% failed within a few minutes too.
The GTLs allowed lowered vtt and mch when first applied at 4.22GHz oc. Didn't notice any further gain when changed GTL again for +.2 vtt.

Have you checked your ram stability?

I changed from 2x2GB Corsair 8500 to 2x2GB G.Skill 8800 SuperPi because the Corsair wasn't happy over 1094. So far the G.Skill only fails if I give it more than 2.0v. (Just testing) Both sets pass Memtest, the bootable cd version, and large fft's in Prime as long as settings are ok. Possible maybe. What stress test is best for vista to push ram in particular?

The last two. Of course. I have not played with them much. Embarrassingly obvious. Will see if they help.

[CryptiK]

Well Prime 95 Custom run with all ram utilized (select custom instead of small or large FFT and set ~800 - 4096K and set ram to use to all your free ram) - this will load your ram very hard. Setting 200 - 800 K loads the ram but also the NB quite hard. Smaller FFT's begin to load the CPU very hard. HCI Memtest is also a nice tool, as is Linx set to max mem.

IMO no one program will test everything fully, so running a suite of programs is really the way to go. Sounds like your system is quite stable hardware wise, perhaps your BSOD's are OS related or ageing PSU related?

[Runecaper]

Hi.

Ok, so i've been reading this thread and tried to understand it, i could use some help if possible though:

I'm running an e8400 at 4.05, with 1.4 vCore (bios setting, 1.36 CPU-Z report) on an EVGA 790i.

As soon as i lower vCore, Core0 starts failing Prime FFT tests. Core1 can go down to 1.26 vCore and still run stable.

I have all GTLref lanes set to auto and they're all at +00mV according to BIOS.

Is there any way i can help Core0 by messing around with GTL settings? Please help me if you can, 1800FSB 24/7 would be awesome but 1.4 is a bit high.