BlackOps/Avenger: GTL Ref Table

[saaya]

im burried in emails and work, but heres a quick headsup for you all :D

Theoretical CPU GTL steps
BIOS setting VTT*
31 0.740
30 0.736
29 0.732
28 0.728
27 0.724
26 0.720
25 0.717
24 0.713
23 0.709
22 0.706
21 0.702
20 0.699
19 0.695
18 0.692
17 0.688
16 0.685
15 0.682
14 0.678
13 0.675
12 0.672
11 0.668
10 0.665
9 0.662
8 0.659
7 0.656
6 0.653
5 0.650
4 0.647
3 0.644
2 0.641
1 0.638

default 0.635

-1 0.632
-2 0.629
-3 0.626
-4 0.624
-5 0.621
-6 0.618
-7 0.615
-8 0.613
-9 0.610
-10 0.607
-11 0.605
-12 0.602
-13 0.599
-14 0.597
-15 0.594
-16 0.592
-17 0.589
-18 0.587
-19 0.584
-20 0.582
-21 0.579
-22 0.577
-23 0.575
-24 0.572
-25 0.570
-26 0.568
-27 0.565
-28 0.563
-29 0.561
-30 0.558
-31 0.556





meassured CPU GTL steps with 8600:
31 0.787
30 0.783
29 0.778
28 0.773
27 0.768
26 0.763
25 0.759
24 0.754
23 0.749
22 0.744
21 0.739
20 0.735
19 0.730
18 0.725
17 0.720
16 0.715
15 0.711
14 0.706
13 0.701
12 0.696
11 0.691
10 0.687
9 0.682
8 0.677
7 0.672
6 0.667
5 0.663
4 0.658
3 0.653
2 0.648
1 0.643

default 0.639

-1 0.634
-2 0.629
-3 0.624
-4 0.619
-5 0.615
-6 0.610
-7 0.605
-8 0.600
-9 0.595
-10 0.591
-11 0.586
-12 0.581
-13 0.576
-14 0.571
-15 0.567
-16 0.562
-17 0.557
-18 0.552
-19 0.547
-20 0.543
-21 0.538
-22 0.533
-23 0.528
-24 0.523
-25 0.519
-26 0.514
-27 0.509
-28 0.504
-29 0.499
-30 0.495
-31 0.490


Ill pass this on to the BIOS engineer and the future BIOSes should have the direct table and no more "+1" or "-4" stuff :)

If theres anything you wanna know please let me know!
Im quite busy since i just got back from a 3 weeks business trip :zombie:
so it might take a few days before i can reply :D

[HDCHOPPER]

exellent man exellent !! this is the kind if info that really helps :up:

[SF3D]

Finally! I was saying this from the start, but it didn't make any difference :)

[yiancar]

Tnx guys this REALLLY helps out:D

[negev]

Could someone explain to the clueless person what this means?

I'm guessing those are voltage adjustments, does that mean that VTT GTL +31 means an extra 0.740v?

[TheGanG]

Actually hate +/-1,2,3 stuff... Now that new values are comparable with other mobos' GTL Ref. voltages, Thanks...

New BIOS Update on these days?

[Xello]

Could someone explain to the clueless person what this means?

I'm guessing those are voltage adjustments, does that mean that VTT GTL +31 means an extra 0.740v?

You're not actually changing any voltages with the gtl setting, it's a reference value that the motherboard uses to determine if a signal is 'high' or 'low' (1 or 0).

[negev]

I'm guessing you need an oscilloscope to actually work this out properly..

[Xello]

Well i tested out GTL refs with this board extensively for my QX9650 (see other thread for results) and the one thing i learned is just to go with what everyone else is using (+10, +5, +10, +10 for the 9650), as after 2 weeks or so of testing this is what i ended up on, and the instability i was having i narrowed down to other settings.

The NB GTL is a different story though, may take experimentation.

When i asked Raja from Anandtech about possible variations of the cpu gtl's he said this:

"The GTL adjustments I typed out to you [+10 +5 +10 +10] are representative of close to ~67% of VTT. Which is pretty much what the 45nm QX9650's prefer as a rule. The scale adjustments on the black ops seem to fall around the 15mv range, so anything away from these values is unlikely to be a whole lot better for most people. While there is variance in substrates across batches, it's unlikely that the variance is so large that GTL's on 2 same model processors should be out by more than 1%. "

[negev]

Yeah I am currently using 10-5-10-10 on my Q9450 and it's stable at 3.33, haven't pushed any higher with this new ram yet. Is what you said likely to also apply to the whole 45nm product range? AFAIK 9450 and 9650 are basically the same just binned differently and one has an unlocked multiplier no?

[Slovnaft]

ooh this is useful
i've never toyed with gtlrefs on my proc cos i didnt know what was sstanddard

[Xello]

Yeah I am currently using 10-5-10-10 on my Q9450 and it's stable at 3.33, haven't pushed any higher with this new ram yet. Is what you said likely to also apply to the whole 45nm product range? AFAIK 9450 and 9650 are basically the same just binned differently and one has an unlocked multiplier no?

Should be, yup, as it's the process that determines the GTL ranges (and dual/quad)

[saaya]

I'm guessing you need an oscilloscope to actually work this out properly..
no you can meassure it with a DMM actually :)
you dont actually change a voltage as in a supply voltage, but there is a GTL voltage which is used as reference to check if a signal on the fsb should be interpreted as a 0 or a 1, and this ref voltage can be meassured.

Ill check where the measuring spots are on different boards and will check how accurate the bios settings are.

so do you guys want the actual reference voltage as a setting or do you prefer the 0.67x vtt setting that asus and others are using?

as for what gtl setting works best, i think even among 9650s theres a difference from cpu to cpu, intel reworked their 45nm process a couple of times and there should be a difference between c0 and c1 stepping as well... but yeah, the settings raja recommends should work well for most 9650s or be close to the best setting :)

if your reading this, thanks again for the good work raja :D :toast:

[HDCHOPPER]

actual reference voltage would be my fav it leaves no guessing or magic questions in my little brain:D

[jolliffee]

Good Progress, any chance the BIOS guys could parse the actual value next to the auto settings so say, we could see what the actual BIOS settings for memory timings next to the auto.

[saaya]

Good Progress, any chance the BIOS guys could parse the actual value next to the auto settings so say, we could see what the actual BIOS settings for memory timings next to the auto.

yes, thats possible, but it takes a LOT of work according to our bios engineers, so they are focussing on memory/chipset/fsb tweaking for now. its def on the list of things we want to add tho :D

[saaya]

updated the first post and added a table i created by meassuring GTL REF voltages, so this table should be more accurate.
ill check with a quadcore tomorrow to see if there are any differences :)

i checked with vtt 1.1v and 1.5v and the ratios are identical and dont change at all like on some other boards.
really solid and reliable GTL REF ratio tuning :D

[Wotcher]

I'm pretty new to this (GTL ref tweaking) so bear with me please, I'm having a little difficulty relating the math to the m/board settings options

Black Ops (500*8) Bios G30 and an E8600 (Q820A599)@4.0GHz, 1.2375V bios



Using this formula: Vtt*0.667+Y = Vtt*0.635

Vtt is 1.2

1.2*0.667+Y = 1.2*0.635

0.8004+Y = 0.762

Y= 0.762 - 0.8004 = -0.0384

so 0.667 - 0.0384 = 0.6386 or Default in the above table (second one)

amirite?

:shrug:

EDIT: Also, did I read somewhere that although the bios/Aegis panel is reporting 1.2V for the Vtt it is actually 1.1V? (45nm dual core)

so the above should read

1.1*0.667+Y = 1.1*0.635

0.7337+Y = 0.6985

Y = 0.6985-0.7337

Y = -0.0352

so 0.667-0.0352 = 0.6318 or -1 in the above table (second one)

[saaya]

hey wotcher :toast:

sorry, dont get why you include Y in your calculations?
actual vtt times ratio = actual gtl ref voltage
and yes, actual vtt for 45nm cpus is .1v lower than the bios shows with G30

[Wotcher]

Hey saaya, I was confused to start with and now I'm not so sure :rofl:

I had the whole thing back to front I think, my setting should be +7 by my latest understanding, as I said I'm fairly new to GTL ref voltage tweaking but I believe I'm learning.

:up:

dropped Vtt back to 1.2V bios (1.1 actual)

1.1x0.667 = 0.7337

1.1*0.635 = 0.6985

0.7337 - 0.6985 = 0.0352

0.635 + 0.0352 = 0.6702

0.6702 = +7 (or there abouts)

I'll give this a run tonight when I get home from work.

I appreciate you taking the time to help me.

:toast:

[Sailindawg]

Wotcher,

That formula was taken from the sticky thread in the Intel forum. That formula makes sense if you have that ASUS board or the BIOS adjusts GTL ref values by giving BIOS entries in mVolts only. That formula helps adjust VTT either up or down of the reference value of 0.67x of VTT or 0.635x of VTT.

What Foxconn did makes more sense. They assigned the various voltages for GTL 0.67x ref values a whole number that's dependent upon the VTT voltage used. All you need to do is simply take 0.667 of a given VTT voltage and look up the corresponding BIOS value according to Saaya's chart (http://depositfiles.com/en/files/8755756). The entire thread is here. (http://www.xtremesystems.org/forums/showthread.php?t=204665)

Saaya created an Xcel spread sheet where you put your VTT of choice in the top entry and the associated values for the BIOS numbers are updated. Take your previously calculated 0.67x voltage and look up the associated whole number quite directly. I usually use a range of GTL ref values until I get one that works. Saaya's chart helps eliminate the guess work when adjusting VTT voltages and GTL ref values.

[Wotcher]

Thanks for that, I saw both thread and chart earlier and that is what tempted me to try tweaking the GTL ref value.

Then I saw the thread here that used the above formula and that is where it turned to turd I think :rofl:

Using the chart it appears I should be around +9, +10, +11 to get my 0.7337 at 1.1 Vtt


I'll get 4.5GHz stable in the end ;)

[saaya]

thx Sailindawg :toast:
glad you got it all figured out in the end wotcher :D

[Vatos_locos]

may i ask where do we measure the GTL on the avenger :p ?

[OdinEidolon]

good to know, but when will avenger be avaiable in EU?

[Vatos_locos]

i/we hope soon :)

[OdinEidolon]

i/we hope soon :)

yeah, me too, i love the design and the 5,25" device

[Vatos_locos]

honestly i would like to have it too to see how it works but it seems i have to wait to be available :)

[ragingclue]

OK I'm trying to wrap my head around this as well. I'm not sure if I'm overcomplicating it in my head or what, but it's pretty confusing.

Let's say, just as an example, I am set to 1.375 in BIOS for VTT (I know it's probably not an option, but it's for the example's sake)

1.375 VTT is actually 1.275

1.275*.667 = .85

So, I find .85 on Saaya's excel spreadsheet after entering the value 1.275 and I see it should be around +11. Would this be true for all four values?

I see many people with quads have had success with the +10, +5, +10, +10 values. Would the same general behavior with GTL's be true for us dualies?

And what about NB GTL?

[Wotcher]

With my E8600 @ 4.0GHz, VTT 1.275 bios (1.175 actual) I run (on Black Ops) -1, -8, -1 -8, dual core cpus will always be a negative value as opposed to the quad positive value.

The -1 is to account for the m/board anomally shown in saaya's "read" values for the E8600 as opposed to the m/boards "default" values

The -8 was arrived at using a combo of saaya's spreadsheet, the GTL calculator by Seban and LinX to graph results with regard to the optimal values.

For a 45nm dual core you need to achieve values as close as possible to .635 as opposed to a quad which utilises .667

LINK (http://www.xtremesystems.org/forums/showthread.php?t=202292&highlight=GTL+ref+voltages)

NB GTL is still somewhat of a mystery to me at this stage

:D

[ragingclue]

omg all this GTL stuff is giving me a headache. I spent about four and a half hours reading up on it yesterday, and I still got it wrong....

I'm really regretting not getting the E8600 now. I wish I had that multiplier of 10.... I'm having trouble finding a happy medium where my chip and my RAM are both running as high as I can get stable on air....

Wotcher, what are your CPU PLL, vcore, SB, and NB voltages that work best for you? I understand everyone is going to have different successful settings, but I want to make sure I'm not way off in left field with any of my values.... Also, I read in one of the threads that you want your PLL, VTT, and vcore all in the same general vicinity? Usually my PLL is a good .3 or so above my vcore and VTT. I also read that you want your PLL and NB voltages to be as far away from eachother as possible, but I always end up getting them pretty close to eachother (within about .06 or so)... so this is where using the NB DTL would come in handy, right? Are these true, or just rumors?

Sorry for all the noob questions, but I just want to make sure I have all the little voltage "rules" and guidelines understood before I go ahead and mess something up or pull my hair out of my head for another few hours doing something that's simply wrong.

[Wotcher]

I'm no guru myself but as I understand it my GTL Ref settings are in the right direction. It seems to work OK for me.

I based my settings on this quote from the thread by cryptiK that I linked earlier.


If you have a 45nm cpu, you are aiming for the voltage given by the 0.635x multiplier, so to work out what to put for the the 0.667x GTL Ref (Y) values (it will be a negative number to make the resulting voltage the same as the 0.635x GTL Ref voltage

saaya posted some actual "read" voltages (for Black Ops & E8600) which showed the .635 to be overvolted at .639 which is why I use -1 for that value as it is less 5.875mV which give around the .634 mark with an actual VTT of 1.175.

Did you d/load the calculator by seban from the linked post?

BTW, I'm running 500*8 for 4.0GHz so I don't use the 10 multi option anyway, I used the same for my E3110 which is basically an E8400. My memory is 1333MHz, I'm considering upgrading to 1600MHz but prices have risen quite markedly with the "recession"

I try to keep my voltages as low as possible due to my geographic location giving high ambient air temps (I live in close proximity, within 100km, of the Tropics)

For 4.0GHz (E8600)

CPU PLL is 1.509
vcore is 1.2375
SB is default (will check actual voltage and edit)
NB is 1.25

With regard to the truth or rumour question, I've never seen these "rules" before and certainly don't adhere to them. Apart from raising vcore, nb and dimm voltages I leave most others as low as I can achieve stability with, I'm not an extreme overclocker in any sense of the description so I've never really bothered to go in depth too much as I can usually manage to attain my desired overclocks using this method. I originally started fooling around with GTL Ref voltages in an attempt to run at a lower vcore but never managed any quantifiable result, in fact I had more luck with a different bios to be honest

:rofl:

[InToGraphics]

Ill pass this on to the BIOS engineer and the future BIOSes should have the direct table and no more "+1" or "-4" stuff :)

I'm using G30 at the moment. Is there a more recent beta BIOS with GTL ref voltages instead of in/decrements ?

Robert