i7 920 stability issues

[Strages]

So, after settling for a less than stellar overclock for about a year, I pulled the i7 920 out of my GF's machine (she wasn't overclocking it, after all) and have tried pushing that one. It does bclk of at least 200 - awesome. However, I'm running into an issue getting it stable. I can get into windows just fine, I can even run about 40 minutes of LinX, but for some reason some games run really, really slow and then crash out to Windows. The weird thing is that some games work just fine. I can play the most demanding sections of Crysis for hours without any issues. Left 4 Dead 2 and a few others, however, won't play for more than a few seconds AND exhibit terrible performance right before crashing out to the desktop.

Upping the uncore multiplier from 16x to 18x seems to fix the choppiness and buys the system an extra minute or so of stability in-game, which I found to be strange. Dropping the CPU Multi to 18x alleviates the problem altogether, resulting in a perfectly stable system. A CPU Multiplier of 19x exhibits the same performance/stability as 20x. Moving from F13h/i to F12 seems to have increased stability a little, as well. I haven't gone back to F9E, which has provided the best overall results to me so far (I plan to do that tomorrow). Basically, I'm looking for some advice in regards to getting past this hurdle. I've tried a VTT as high as 1.4v and VID of 1.376 together so far, but given that I get ~40 minutes of LinX with just 1.36, I'm not sure increasing voltages will even help. It seems as though games that partially load all four cores together, rather than fully loading one or two of them, are the ones exhibiting stability problems, but I haven't been able to confirm this completely.

I've also upped the PCIe frequency to 103 (doesn't boot higher than that), turned off PROCHOT, increased CPU Clock Drive to 1000mv and clock skew to 200ops, and disabled load-line calibration. None changed a thing.

Here are the settings I'm using - does anyone have any ideas as to 1) what might be causing the choppiness and/or 2) some idea of how to get this system stable at 20x200 (my desired 24/7 clock)?

i7-920 C0 3839A
Gigabyte GA-EX58-UD5 w/F12 BIOS

CPU Clock Ratio – 20x

Advanced CPU Features:-
CPU Clock Ratio - 20x
Intel (R) Turbo Boost Tech. - N
CPU Cores Enabled - Y
CPU Multi-Threading - N
CPU Enhanced Halt (C1E) - N
C3/C6/C7 State Support - N
CPU Thermal Monitor - N
CPU EIST Function - N
Virtualization Technology - Y
Bi-Directional PROCHOT - Y

QPI Link Speed - 36x

Uncore & QPI Features:-
QPI Link Speed - 36x
Uncore Frequency - 16x
Isochronous Support - Y

Base Clock (BCLK) Control - Y
BCLK Frequency (Mhz) - 200

Advanced Clock Control:-
Base Clock (BCLK) Control - Y
BCLK Frequency (Mhz) - 200
PCI Express Frequency (Mhz) - 101
C.I.A.2 - N
CPU Clock Drive - 700
PCI Express Clock Drive - 700
CPU Clock Skew - 0
IOH Clock Skew - 0

Performance Enhance -
Extreme Memory Profile (X.M.P.) - N
System Memory Multiplier (SPD) - 8
DRAM Timing Schedule (SPD) - Quick

**The following 5 options need setting for each stick of ram**
CAS Latency Time - 8
tRCD - 8
tRP - 8
tRAS - 24
Command Rate (CMD) - 2

Load-Line Calibration - Y
CPU Vcore - 1.366 (effective)
QPI/Vtt Voltage - 1.36
IOH Core - 1.32
DRAM Voltage - 1.66

Advanced Voltage Control:-
Load-Line Calibration - Y
CPU Vcore - 1.366 (effective)
QPI/Vtt Voltage - 1.36
CPU PLL - 1.96
PCIE - 1.5
QPI PLL - default
IOH Core - 1.32
ICH I/O - default
ICH Core - default
DRAM Voltage - 1.66

[ReverendMaynard]

I ran 195x21 for a year on a C0 with the GB Extreme X58 which is still running in a co-workers comp who bought it off of me.

1.375vcore(set) 1.344v(drop) 1.326(droop)
1.84v PLL
1.10v QPI/VTT
36x
16x
1.6v DIMM
CPU Clock Drive - 800mV
PCIE Clock Drive -900mV

[Strages]

I ran 195x21 for a year on a C0 with the GB Extreme X58 which is still running in a co-workers comp who bought it off of me.

1.375vcore(set) 1.344v(drop) 1.326(droop)
1.84v PLL
1.10v QPI/VTT
36x
16x
1.6v DIMM
CPU Clock Drive - 800mV
PCIE Clock Drive -900mV

That's what I ran for a while. I'd really like to get 20x200 working though - I just like the idea of using my DDR3-1600 memory to the fullest!

Any ideas?

Also, Reverend Maynard as in Disposition by TOOL?

[ReverendMaynard]

That's what I ran for a while. I'd really like to get 20x200 working though - I just like the idea of using my DDR3-1600 memory to the fullest!

Any ideas?

Also, Reverend Maynard as in Disposition by TOOL?

Turbo mode, 21x200 should be a snap. I notice you're running vcore and QPI VTT the same voltage, and allot of testing I went through showed VTT needs to be few points lower, like the settings I posted.

Here's a some golden settings I had under water, YMMV of course.
http://www.xtremesystems.org/forums/...&postcount=777

And yes, TOOL/Reverend Maynard....track# 69 off of Undertow called Disgustipated

[Strages]

Doh, sorry, I thought you were giving me your settings at 195x21! I will give that a shot. Some testing I've done hints at a higher uncore multiplier actually improving stability, which doesn't make sense to me. Additionally, for some reason, when leaving the uncore multiplier on Auto, it even sets it to 19, which I thought was way too high (Uncore must be <= QPI, correct?). The default uncore multiplier is supposed to be 16, right? I changed back to an older bios that has proven to be a lot more stable and will be trying 19x200,1.4 vcore, 1.36 vtt, 16x uncore later this evening.

Bah, I meant Digustipated, not disposition - that's the track right after Lateralus!

[Strages]

Another question: I know that some people have pushed the vcore on i7's well past 1.5v, but what is the highest 24/7-acceptable vcore one should run? Obviously it's going to be based on a lot of factors, the individual processor in particular, but is, say, 1.45-ish (drop; before droop) safe for 24/7 operation under water? I haven't really been comfortable with anything higher than 1.376v, but that's mainly because I'm not sure how high is "too high."

[ReverendMaynard]

Another question: I know that some people have pushed the vcore on i7's well past 1.5v, but what is the highest 24/7-acceptable vcore one should run? Obviously it's going to be based on a lot of factors, the individual processor in particular, but is, say, 1.45-ish (drop; before droop) safe for 24/7 operation under water? I haven't really been comfortable with anything higher than 1.376v, but that's mainly because I'm not sure how high is "too high."

1.45v would be my limit, but it really comes down to temps. On air that would get you easily over 100C running something multi threaded, my personal rule of thumb with the i7's is to keep them under 90C and you're golden. I think for air 1.38v would be getting up there but a nice water loop should handle 1.45v 24/7.

As for uncore multi, 17x on the GB board that I had was the best option hands down.

[Strages]

Well, I finally got 19x200 stable last night. It required me bumping the vcore to 1.392 (1.425 set) and 1.4v VTT. It may have been stable with 1.36 VTT, but I tried so many different things I can't remember (at work now). I did try bumping the vcore up another few notches to get 20x200 stable, but no go. I'll probably have to put a lot more voltage into it, which I'm not sure I want to do. Though, if staying below 90C is the goal, I have a lot of headroom - this system hits ~64C under LinX and rarely breaks 53C or so under gaming conditions. I'll have to give the 17x multi a try - I've got it set to 16 right now.

It still puzzles me that 20x200 can be perfectly stable in LinX for ~40 minutes, but then crash out of some games in seconds.

[ReverendMaynard]

Well, I finally got 19x200 stable last night. It required me bumping the vcore to 1.392 (1.425 set) and 1.4v VTT. It may have been stable with 1.36 VTT, but I tried so many different things I can't remember (at work now). I did try bumping the vcore up another few notches to get 20x200 stable, but no go. I'll probably have to put a lot more voltage into it, which I'm not sure I want to do. Though, if staying below 90C is the goal, I have a lot of headroom - this system hits ~64C under LinX and rarely breaks 53C or so under gaming conditions. I'll have to give the 17x multi a try - I've got it set to 16 right now.

It still puzzles me that 20x200 can be perfectly stable in LinX for ~40 minutes, but then crash out of some games in seconds.

I do know that some games and HT don't jive, so voltage isn't going to do much.

If you have that much headroom, I'd still try 1.45v max. C0 920's are tough buggers, don't be shy if you have those temps. Just keep your QPI VTT a few points below, like vcore - 1.45v and QPI VTT - 1.425v.

[Oztopher]

Just keep your QPI VTT a few points below, like vcore - 1.45v and QPI VTT - 1.425v.

+1 to this. I've found the same. Although i don't just shove the vtt up, adjust cpu multi, bclk and uncore so it actually needs that ratio of cpu/vtt.

[Strages]

I do know that some games and HT don't jive, so voltage isn't going to do much.

I always have HT is disabled, so that's not the issue. I'll try a few other things tonight - maybe I will try out my previous chip, as well. I could never get it into windows with a 200 bclk, but I may have been unwittingly allowing the gigabyte board to set an uncore mutli of 20x. Anyway, I'm considering just selling some old gear I'm not using to raise funds for a used D0 or something. ;P