Can't figure out why i7 920 not stable at 4GHz...

[r2rX]

Hey guys,

I recently set up a system with the following components:

-i7 920 D0 (Bloomfield) CPU
-MSi Big Bang X-Power X58 Motherboard (v1.6)
-3x2GB Corsair Dominator GT (CMT6GX3M3A2000C8) 2000MHz RAM
-MSi GTX 480
-1KvA SilverStone PSU

So all the hardware is working fine; no complaints.

However, my OCing experience with this equipment has been....interesting so far.

My goal has been to get the CPU clocked to 4 GHz and the memory at 2000MHz. So, ideally, the bclk = 200 and multiplier = 20.

I know that there are a number of factors to keep in mind (mainly VCore, QPI/VTT and RAM Timings) which I have researched and tested with. But, irrespective of what settings I have tried or changed, I cannot get my dream configuration working.

At the moment, my machine is set to the following:

BCLK = 193
CPU Vcore = 1.344
CPU PLL = 1.950
QPI = 1.59
DRAM Vcore = 1.65
DRAM Timings = 8 : 9 : 8: 24 : 1T
Multiplier = 21 (EIST enabled to allow 21x)
Memory @ 2000MHz (@ 5x Ratio) (2:10)

Total Speed = 3860 MHz (+ 1 core @ 4053 MHz due to EIST)

The above settings are stable (ran LinX with no errors; I read that the latest version of LinX is a more accurate testing method than Prime95 but also tested with Prime95 and stable).

But when I change the BLK to 194 or above, it is no longer stable; irrespective of what settings I change.

Now, the only settings I manually configured were the VCore, DRAM Voltage and DRAM Timings....the CPU PLL and QPI/VTT were set to AUTO in the BIOS.

This is what confuses me a little, though. In the BIOS, the max value for the QPI/VTT I can set is 1.52....yet, when left on AUTO; and checking the value in Windows via the MSi Control Center, it says it's set to 1.59 (of 1.60 absolute max in Control Center). I also get the identical value when settings my system to 200x20.

Again, I have experimented changing the RAM timings to "loosen" them a little but it doesn't help... and the above written timings are what I am running on on this stable overclock. When running at 200x20, LinX will crash after 3-4 seconds, essentially freezing my entire system and requiring a cold boot or indicate errors....and eventually have a system lock up.

All the other settings in the BIOS, left on AUTO, register that they are set to default values (i.e. IOH etc).

I also tested multiple configs, leaving the BCLK @ 200 MHz, where I change the multiplier to 12x and going up (thus CPU running @ 2400 MHz and incrementally being increased) and/or changing the RAM Speed (1200MHz, 1600MHz).....I still have the same problem.

....so the only thing that I can think off is that either i'm not doing something correctly/missing something or my CPU (or hardware config in total) does not like running above a BCLK of 193.

That's the jist....if there is any other information you'd need to help out, let me know.

Hope I can sort this out.

r2rX

 

[Woomack]

I would try lower cpu multi like x19 or x20 with 200bclk and turn off EIST. Check everything with memory @1600 and ~1.4V QPI/VTT. If you make it stable then change it to 2000 and ~1.5-1.55V QPI/VTT. Also try IOH 1.18-1.25V. If you have LLC options ( I don't know this board ) then set it to higher lvl.
For the test time set some higher cpu voltage like 1.36-1.40V and when you set all stable just try to drop it a bit.
CPU PLL usually works best from 1.80-1.85V ( sometimes higher but for 4GHz you won't need it ).

 

[r2rX]

I've have run similar tests but I will attempt it once more and let you know. Thanks for the feedback, Woomack.

r2rX

 

[dejo]

its rather common at those speeds to need to increase the pci-frequency by a few points. try that and report back

 

[r2rX]

Will test and report back very soon. B.T.W, i've got my PCI-e @ 110; I also did my tests with it set at 100, so I know for sure it is not that either. There is also the IOH PCI-e option...but I really doubt that will make a difference.

r2rX

 

[dejo]

if you are already at 110 on pcie freq then that should be enough, maybe your chip just isnt up to the task

 

[r2rX]

My tests, so far, have reported the same results as i've experienced the last couple of days.

Here are the results:
(Following are results with IOH set to 1.25 and defaults)

I've set the BCLK to 200 and the multiplier to 19x (although the results are the same irrespective of multiplier). I've set the CPU voltage to 1.4v. As for the QPI, it would not load Windows / boot stable below 1.48.

I started my machine with the QPI set to 1.4; the system would hang as Windows attempted to start.

I increased it to 1.42, and as Windows was loading I got his BSOD: 0x3B (which refers to Vcore). Alright. I increased the Vcore to 1.42 and the QPI to 1.44.

On this boot, it would enter Windows but while loading up startup programs it gave another BSOD: 0x124 (which refers to increasing either the VCore or QPI/VTT). Alright. So I upped the QPI to 1.46.

Started Windows again. This time it loaded properly and startup programs loaded fine. Then I ran LinX. It hung after 2 seconds and gave another BSOD: 0x0A (which refers to unstable RAM/IMC; solution being to increase QPI and, if fails, increase VCore). Alright. So I upped the QPI to 1.48 and the VCore to 1.46. (Note: I have no IMC option in the BIOS).

Now I enter Windows again and run LinX. It crashes after 4 seconds and BSOD's with a 0x124 error. So I increase the QPI to 1.52 (which is max on my BIOS). When I run LinX, it will freeze (par normal) but just hang now....no BSOD's. Even if I increase the Vcore (or change anything else) that is as far as I go. When playing games, they eventually crash.

As mentioned before, the only constant that i've noticed is that when the BCLK is set to 200, I get freezing...irrespective of what settings I try / manipulate.

So is this a case of this particular CPU not being able to handle BCLK of 200? Cause the same instability happens the moment I set the BCLK to 194 (up to 200).

Another interesting thing. I don't know how accurate MSi Control Center is but when I check the stats, it still registers the QPI at 1.59 (even though it's set to 1.52 in the BIOS) and determines the CPU PLL as 1.95 (even though it's set to 1.80 in the BIOS). Now if I change either settings, through MSi Control Center, my machine hangs....so i'm wondering if there is a correlation between this effect and my instabilities; outside of my CPU simply not being able to cope with BCLK of 200.

There you go......

Any other info/tests required, let me know.

EDIT: Just read this thread, http://www.overclockers.com/forums/showthread.php?t=698334, and the gentlemen seems to have a similar problem....and solution...well, more like a work-around. So it seems i'm not the only one.

r2rX

 

[redduc900]

Like Woomack suggested above, at a BCLK of 200 lower the DRAM multiplier first to x6 = DDR3-1200, then to x8 = DDR3-1600, checking each w/ Memtest86+ before attempting to boot into the OS. You can manually set the timings and voltage as per the SPD tab of CPU-Z to match the lower frequencies (only adjust the four primary timings, and leave all the sub-timings on Auto). And at the lower DRAM frequencies you can probably just leave QPI voltage set to Auto. You could also try enabling the DDR3-2000 XMP profile if you haven't already.

 

[r2rX]

I've already tested the minimum DRAM multiplier up to the multiplier that equals 2000Mhz, maintaining the BCLK at 200..... the result is the same, unfortunately.

I only adjust the 4 initial timings of the RAM (tested 9-9-9-24 and 8-9-8-24; the latter being the XMP settings).

I will attempt it once more.....

r2rX

 

[r2rX]

Alright.

I followed your recommendation, redduc900. The results are interesting....rather, I noticed something that I didn't before.

There is the option, with the RAM Speed, to select 1200, 1600 and 2000. On both 1200 and 1600, when I run LinX, the system halts but not frozen entirely...after a few seconds the desktop is responding and then halts again. Interestingly, if I press my power button, the desktop eventually responds again and my system shuts down...but this occurs within the first 15-20 seconds of LinX running...if I wait longer than that, then the system freezes entirely and BSODs (the consistent error is 0x124).

If the system is set to 2000, when running LinX, the system halts completely....and shows a green screen (which will flicker a little).

When this was happening, during my initial tests, I couldn't get it stable...regardless of how high I set the QPI (which is 1.52 max in BIOS) and VCore (I even set it to 1.55v JUST to make sure...even though it's far more than the CPU, on 4GHz, will ever need) or other misc settings.

What do you guys think?

r2rX

 

[Mimesis2]

Alright.

I followed your recommendation, redduc900. The results are interesting....rather, I noticed something that I didn't before.

There is the option, with the RAM Speed, to select 1200, 1600 and 2000. On both 1200 and 1600, when I run LinX, the system halts but not frozen entirely...after a few seconds the desktop is responding and then halts again. Interestingly, if I press my power button, the desktop eventually responds again and my system shuts down...but this occurs within the first 15-20 seconds of LinX running...if I wait longer than that, then the system freezes entirely and BSODs (the consistent error is 0x124).

If the system is set to 2000, when running LinX, the system halts completely....and shows a green screen (which will flicker a little).

When this was happening, during my initial tests, I couldn't get it stable...regardless of how high I set the QPI (which is 1.52 max in BIOS) and VCore (I even set it to 1.55v JUST to make sure...even though it's far more than the CPU, on 4GHz, will ever need) or other misc settings.

What do you guys think?

r2rX

This may be a stupid suggestion, but beware I have no past experience with 1366. Try putting your bclk down to 191 and increasing your multiplier to 21, (191 x 21 = 4011) test, then report back.

 

[r2rX]

Hey, Mimesis 2.

If you noticed (on my first post), i've currently got my system stable on 193x21 (although, the extra speed from the 21x multiplier only applies to one core). The max multiplier I can use is 20x, but if I enable EIST then I get up to 21x.

Could it be that my CPU simply doesn't want to function on a BCLK beyond 193? The reason why I really want to get it working on 200 is so I can have my RAM running at the full 2000MHz (as opposed to 1930Mhz that it's on now).

Perhaps the extra 70MHz won't make much difference and the difference of my CPU being clocked at 3860MHz is not so different to 4000MHz...but I would love to get it there if possible.

r2rX

 

[Woomack]

I think it's still better idea to make it run with memory @1600 and 200bclk or go higher to 210-215 bclk with x19 cpu multi. Overall performance will be the same and you can keep lower VTT voltage and lower temps.
Your RAM is PSC based and should work @1600 with 6-8-6-24 1T timings, ~1.60V ( +/- 0.05V ).
I know that there are things that you don't need but just want
You can check my threads about ADATA 2000G memory that is based on almost the same chips as your Dominators:
http://www.overclockers.com/forums/showthread.php?t=662361
http://www.overclockers.com/forums/showthread.php?t=652855
Maybe you will find some info about sub timings or other settings there.
I'm running both of these kits together now as 12GB 1680 ( 210 bclk ) 7-8-7 1.62V, ~1.43V VTT.

 

[r2rX]

Alright, Woomack. I'll test it out again and see how it goes.

...but do you have any idea why it is unstable? Cause i've already tried 200x20 (and less) with the memory set to 1600 (and testing different timings) and it's unstable. If I have the BCLK at 193 (or less) then it's fine...whether the RAM is on 1200, 1600 or 2000.

r2rX

 

[Woomack]

check 200 bclk with lower cpu multi like x12, x15 etc ... if you make it stable on lower multi then your cpu just won't make 200 on x20+ ... did you check if there is any new bios ? ( don't know if it will help but it's always good to try )
no better idea now and I'm at work

 

[r2rX]

My board is on the latest bios (v1.6). On BCLK @ 200, it isn't stable irrespective of which multiplier I set it to.... that's why this has been confusing me.

B.T.W, thanks for the help so far Woomack (and everyone else). I appreciate the great feedback.

r2rX

 

[xrror]

Maybe check uncore multiplier?

It just struck me as odd that the i930 I had seemed to have a hard wall at 191 bck also... but I was a dummy and never thought to check my uncore multiplier (I had it way high).

Maybe lower it and see if that helps? I suppose you could also crank VTT voltage to like 1.6v, but ... you might want to save that as a last resort and by last I mean "you hate your chip"

On Bloomfield the Uncore multiplier should be at least twice that of the memory multiplier. So assuming it's not already at that lowest ratio, you could try lowing it one.

 

[djscrew]

I have had a similar experience with my overclocking recently, I have stopped at 191 due to heat constraints and instability due to undervolting for these OCs.

I would suggest trying to slacken your timings to 10-10-10-30-2T and see if that helps, then increment back down to 9-9-9-24-1T if you can.

I would focus on the ram. Are you running AIDA 64/Everest to check voltages in windows? I noticed that during stress testing with a high RAM and QPI overclock, my QPI voltage would dip dramatically during stress testing, once it dipped low enough the system would lock and reboot without any identifying error code.

I would recommend you be careful if you want to keep your components intact. Overclocking PCIE, and overvolting as far as you are is dangerous to your components ^^

If you intend to proceed forward however, I would recommend focusing your attention to QPI/IOH voltages.

my sig OC is done with ioh of 1.2 (AIDA 64 has it at 1.184) and QPI at auto (AIDA 64 has it averaging around 1.40, dipping to 1.35 during stress testing.

Do you have LLC enabled? I found it significantly increased system stability for me.

Also try overvolting your DRAM a tad.

EDIT: as stated in the above post, you do have your QPI set to lowest frequency available short of "slow mode" I hope.

 

[r2rX]

Hey guys.

To answer some of the questions, the following are my settings:

BCLK = 200
Multiplier = 20
Memory Ratio = 5 (to get DRAM 2000MHz)
Uncore Ratio = 10 (to get 4000MHz ; double the RAM value)
QPI Frequency = 4.800GT (resulting in QPI Frequency @ 7200MHz)
PCI-E Frequency = 100 ( no difference @ 110, but safer on 100)
DRAM Voltage = 1.65 (tested on 1.7 but results the same)
CPU Voltage = 1.350 (with droop it is 1.344)

These are the base settings. The CPU Voltage might seem a bit high but i've followed the patterns that i've seen when the CPU Vcore is set to 'Auto'. On Auto, the CPU Vcore is 1.31v. When running LinX (for example), it jumps from 1.31 to 1.34...and then BSODs with the error 0x101 (which implies increasing Vcore). So I manually set it to 1.34v and, when being stress-tested, increases to 1.36v....with this, specifically, it does not BSOD with a Vcore-specific error. I've tested putting the Vcore lower than 1.31, but it is not stable....so those who can get their 920 D0 @ 4GHz with less than 1.3v are fortunate.

The following are the RAM timings that i've experimented with: 8-9-8-24-(1T and 2T tested), 9-9-9-24-(1T and 2T tested) and 10-10-10-30-(1T and 2T tested). I've not seen any difference, in relation to stability, using any of the above timings.

Now, the following is the progress i've experienced so far......

Part of the issue I was having was definitely QPI related. My BIOS limited the max value to 1.52. However, I remembered that there is a switch on my board that increases the cap value in my BIOS. So, once switched, the max QPI value went to 1.75.

So, I started testing...and, basically, I managed to get something semi-stable..ish.

VCore = 1.350v
QPI = 1.650v

I spent a couple of hours testing the values between these two. The higher the Vcore, the lower the QPI can be (i.e. VCore @ 1.350 is "stable" with QPI @ 1.650 but Vcore @ 1.375 is not stable with the same QPI etc). I tested from low Vcore and low QPI and increased QPI. Then increased Vcore a little and retested with low QPI and then increasing QPI etc.

So, basically, the closest to the "sweet spot" that i've discovered so far is Vcore @ 1.350 and QPI @ 1.650. This configuration is the only one where i've managed to pass a couple of LinX tests without crashing immediately...although it will only pass with 512MB selected...and will eventually crash after 5-10 passes. Increasing the mem size beyond 512 results in immediate crashing. Prime95 crashes but not immediately.

Irrespective of CPU Vcore values i've tested, the QPI will not be stable at 1.35 or below. So, if I set the QPI lower than 1.65, I either get booting issues (which occur with low values i.e. 1.4 and less) or instability/crashing when stress testing. If I set the QPI higher than 1.65 my computer turns off when stress-testing.

The hours of testing included trying out different RAM timings (and voltage), testing with PLL and IOH values.

The end results is that when the CPU Vcore is at 1.350v and the QPI is at 1.65, the results are the same irrespective of PLL, IOH or RAM (timing and voltage) settings.

Concerning read-outs in AIDA64, when selecting 'Motherboard' -> BIOS , it should list BIOS Properties, BIOS Settings and BIOS Manufacturer; the BIOS Settings being the displayed info CPU PLL, Voltage, QPI etc. On my system, the BIOS Settings are not present; only BIOS Properties and BIOS Manufacturer....so I can't use AIDA64 to monitor those values while stress-testing.

The only other option is MSi Control Center...which is showing some strange results. It doesn't detect the correct QPI value when I set it manually and when left to Auto (in the BIOS) it picks it up as 1.20...and then changes to 1.59. MSi Control Center also detects IOH @ 1.45.....and then changes to 1.10....and the CPU PLL @ 1.95.

And one more update: I enabled the OC-Genie button on the motherboard, then went into the BIOS and checked it out. The CPU and RAM were clocked slightly lower than my settings...but it auto-adjusted 4 settings: VCore @ 1.4, QPI @ 1.51, IOH PCI-E @ 1.548 and DRAM Voltage @ 1.65v........those were the only settings adjusted; everything else was left on AUTO. I replicated these settings on my clocks but it does not work (i'd come across the same combination during my hours of testing prior).

...so what do you guys think?

r2rX

 

[xrror]

Memory Ratio = 5 (to get DRAM 2000MHz)
Uncore Ratio = 10 (to get 4000MHz ; double the RAM value)

Hrmm. Uncore over 4Ghz without a ton of VTT voltage is kinda difficult, isn't it?

I never had luck stabilizing over 3.8Ghz uncore without suicide voltages, but I may have been doing it wrong too. Hopefully others can chime in with experience on this.