Unstable system with ram above 1700 Mhz

I have inserted my specs in my profile.

I think I have found a "quite" stable config for my computer, it is:

(last bios installed 0809)

BCLK: 170 MHz

CPU frequency: 3570 MHz (21 x 170)

Ram frequency: 1704 MHz

UCLK: 3408 MHz

CPU volt: 1.15

QPI volt: 1.35

Dram bus volt: 1.65

Timings: 8-8-8-24 (1N)

With this settings running memtest86+ for 5.30 hours; I receive 3 errors, all in test #7:

TST PASS     FAILING ADDRESS         GOOD         BAD      ERR-BITS   COUNT 
7     0      00117575464-4469.3Mb    36372EB3  34372EB3  02000000   1
7     1      00117A0D464-4474.8Mb   7E692DFA  7C692DFA  02000000   2
7     8      00117AB5464-4474.3Mb    FB17D102  F917D102  02000000   3

Total runtime: 5 h 30 min
Passes: 9 

1) Should I be aware and fix this? How? I found that it could be a temp problem but my ram is at about 30°C (I have put a termal sensor and there is DHX).

2) Is there a way to obtain a stable overcloking with ram @ 1800-2000? Every time that I try to go above 1700, windows freezes during boot. It also freezes when I set X.M.P in BIOS (others settings on "Auto")!!

Thanks

Maybe just the top end of your CPU

Sorry, I don't understand...

what do you have the QPI Voltage set to for the memory controller?

My QPI voltage is 1.35. Is there another QPI voltage for the memory controller?

And I would try and set the Command Rate to 2T as well and see if that helps.

Ok, should I try this to fix errors in test #7 or to increase frequency?

And do you have a (D0) Stepping CPU?

Yes, I have a D0 stepping CPU

No, that's wrong because even if I don't overclock CPU, I can't get a stable Ram at 1800-2000 Mhz:

Setting everything on "Auto" in BIOS and just using X.M.P. Profile (which means ram at 2000Mhz, Dram Bus 1.65, QPI volt 1.40) windows doesn't start.

And I would try and set the Command Rate to 2T as well and see if that helps.

CPU-Z says that my current Command Rate is 1T but from BIOS I can't find a way to modify it. I searched in OC and Timings options but I didn't find it...

I don't find a way to modify Command Rate on my Asus Rampage II Gene with i7 Core 920 D0...

XMP is always unstable!

Ok, I have done a lot of tests.

First of all I resetted all BIOS settings to AUTO and then I enabled X.M.P profile changing QPI volt to 1.35

a) So settings were:

2000Mhz, 8-8-8-24-2N, QPI 1.35, DRam volt 1.65

System does not boot (screen locks-up during Windows boot).

b) Same settings, but changing QPI volt to 1.40

2000Mhz, 8-8-8-24-2N, QPI 1.40, DRam volt 1.65

System does not boot (screen locks-up during Windows boot)

c) So I tried some manually config:

2000Mhz, 9-9-9-25-2N, QPI 1.40, DRam volt 1.65

System freezes after 10-20 secs (screen lock-up)

d) A lot of other tests:

1800Mhz, 10-10-10-26-2N, QPI 1.35, DRam volt 1.65

System freezes surfing on the web after 1 min (screen lock-up)

Ram 1708Mhz, 8-8-8-24-2N, QPI 1.35, DRam volt 1.65

Proc 3800Mhz (BCLK 213Mhz)

System freezes surfing on the web after 1 min (screen lock-up)

Ram 1600Mhz, 8-8-8-24-2N, QPI 1.3475, DRam volt 1.65

Proc 3800Mhz (BCLK 200Mhz)

System stable testing with Prime95

In every test (except with X.M.P profile where everything was on "Auto") UCLK was RamFreq x 2. IOH and ICH volt on Auto. PLL volt on Auto.

So... there is no way to go above 1700Mhz and don't get lock-ups in 1 min!

What should I do? Again, no way to change Command-Rate.

Edit: another question. Why can't I find my RAM (TR3X6G2000C8GTF) in your online shop? https://shop.corsair.com/store/default.aspx?category_id=766409

Like I said more then likely just the top end of that CPU.

Top end of that CPU?

I can set my C.P.U freq on Auto (2.4-2.6 GHz), enable X.M.P. or try a manual overclock to 1800MHz and still can't boot my computer...

Do you mean this isn't a ram problem? I have never booted my computer with ram speed above 1700MHz. No one bios-config is stable!

Yes, I tried, and still not reach 2000MHz.

They run at 1600MHz but they don't run at 1866MHz

So do you think that i7 920 D0 can't run RAM above 1800?

Do you know, at Corsair, anyone running dominator at above 1700MHz with Intel Core i7 920 D0?

If yes, maybe I can try to replace my modules...

I have a 920 D0 and it runs at 4.2ghz HT on @ 1.43v RAM at 2000 7-8-7-20 2N @ 1.65v, QPI volt is 1.625 in BIOS. I don't know why but my CPU needs every bit of the QPI voltage to push the mem at that speed, not common of a D0. I've tried everything starting at 1.325v QPI and it doesn't stabilize until 1.625v QPI (BIOS reports 1.60v actual).

My temps are too high for my liking with those settings, so I'm happily stable at 4.4Ghz HT off @ 1.39v RAM at 1683 6-7-6-17 2N @ 1.65v, QPI is ~1.375v. I tried to push the RAM to 2105 7-8-7-20 2N and it just won't do it. The QPI needs to be over 1.625, and I'm just not doing it, no way. The XMP settings worked fine for me straight out of the box with 1.625v QPI and no OC on the CPU.

It does sound like the CPU is the culprit to me. I would try to set the QPI at 1.625v and back it down slowly til you get the lowest stable voltage instead of the 1.4v you were using. WATCH THOSE TEMPS!!! 1.625v QPI does increase the core temps quite a bit. If you have adequete cooling you should be able to do it. I am underwater and the CPU core temps with 1.625v QPI were in the mid-upper 80's ©. Now I don't break 80 ©. Temps taken with RealTemp 3.0, tjmax set to 100.

EDIT: My RAM is the C7 set not the C8 so my timings should be tighter than yours at the same speed and voltage.

If you are using the stock cooler, I would not recommend setting the QPI above 1.375v regardless of what RAM you have. The Dominator GTs definetly cause more heat to the CPU than slower rated modules due to the QPI voltage. But of course, all parts are different and just because my settings work for me doesn't mean they will work for you. Good luck. :D:

Very useful information dagimp16, thank you a lot!

However I have asked in some forums and there are a lot of people running ram @2000MHz with Intel Core i7 920 D0, they all use high QPI voltage.

So I have tried to enable XMP profile without overclocking CPU and to set QPI voltage to 1.625 but my computer still doesn't boot.

Now I'm running CPU @ 4028Mhz 1.25v and ram @ 1700MHz 1.65v, QPI 1.3625. Memtest reports 2-3 errors always in test #7 (in 5 hours) and always with the same bit and in the same memory area (please see the first post of this thread).

Maybe I have a Bad Part?

Considering a possible RMA, I have a quite "old" Corsair 4 x 1GB DDR3 XMS memory (dual channel). Could I run it with i7 and Rampage II Gene or is it incompatible?

Same here with the CMG6GX3M3A2000C8

cant reach the 2000MHz

Im also overclock at 4GHz 1.400v (bclk 200 x20), QPI 3.6GHz 1.515.v

NB 3.8GHz

max stable RAM 1600MHz 9,9,9,24,74,1T ratio 2:8

I tried the overclock with XMP Profile 1 (enable)

...nothing, still crash!

Very useful information dagimp16, thank you a lot!

 

However I have asked in some forums and there are a lot of people running ram @2000MHz with Intel Core i7 920 D0, they all use high QPI voltage.

 

So I have tried to enable XMP profile without overclocking CPU and to set QPI voltage to 1.625 but my computer still doesn't boot.

 

Now I'm running CPU @ 4028Mhz 1.25v and ram @ 1700MHz 1.65v, QPI 1.3625. Memtest reports 2-3 errors always in test #7 (in 5 hours) and always with the same bit and in the same memory area (please see the first post of this thread).

 

Maybe I have a Bad Part?

 

Considering a possible RMA, I have a quite "old" Corsair 4 x 1GB DDR3 XMS memory (dual channel). Could I run it with i7 and Rampage II Gene or is it incompatible?

Could you help me, please?

Thanks