Need help getting 4Ghz stable

[lethial]

I have been playing with my DFI X38 LT and E8400 for a while now, and I can't seem to get a good 4GHz 24/7 OC

Main BIOS Page
Exist Setup Shutdown......................Mode 2
Shutdown After AC Loss....................Disabled
O. C. Fail Retry Counter..................0
CLOCK VC0 Divider.........................Auto
CPU Clock Ratio...........................9x
CPU N/2 Ratio.............................Disabled
CPU Clock.................................445 MHz
Boot Up Clock.............................Auto
DRAM Speed................................333/800
PCIE Clock................................100MHz
PCIE Slot Config..........................1X 1X

CPU Spread Spectrum.......................Disabled
PCIE Spread Spectrum......................Disabled
SATA Spread Spectrum......................Disabled

Voltage Setting Page
CPU VID Control...........................1.2075 (The aim is to get it so that voltage goes from about 1.21V to 1.34V, hence the Special Add below)
CPU VID Special Add.......................108.50%
DRAM Voltage Control......................2.120V
SB Core/CPU PLL Voltage...................1.510V
NB Core Voltage...........................1.41V
CPU VTT Voltage...........................1.100V
VCore Droop Control.......................Enabled
Clockgen Voltage Control..................3.45V
GTL+ Buffers Strength.....................Strong
Host Slew Rate............................Strong What does this do anyway?
GTL REF Voltage Control...................Enabled
CPU GTL1/3 REF Volt.......................78
CPU GTL 0/2 REF Volt......................76
North Bridge GTL REF Volt ................60 (These are 63% numbers)

I didn't play much with the memory settings I used standard 5-5-5-15 with performance set to 8 (7 effectively). Oh and my Corsair Dominator PC-8500 2x2GB doesn't like the "More aggressive" settings, is that normal for these modules? The are not Micron chips anymore.

Ch1 Clock Crossing Setting................Nominal

Ch2 Clock Crossing Setting................Nominal

Ch1Ch2 CommonClock Setting................Nominal

Am I taking the wrong approach completely? It seems that the E8400s should be able to hit 4Ghz with Vcore < 1.3V, so I don't really need to enable the temperature management features of the CPU?
Anything else that I should tweak to get a 24/7 stable 4Ghz OC?

While on that subject, when you guys get a 24 hour Prime Stable OC, do you seem to get slower response time in windows? I swear, Vista seem more responsive w/o any OC...

I need to tweak less and play more games instead :P

[Clunk]

So as not to hijack the other thread, I'm going to shift this to it's own thread, seeing as it's a different board

You haven't got any system specs listed, so it's hard to tell what the problem could be.

At a guess, it looks as though you have the RAM set too high. Try the 333/667 strap.

[lethial]

Hehe sorry about that, I didn't want to clog up the forum with another bother, but you are right, it is much better this way

Is my PC Spec not showing up? I hope I saved it correctly...

I could definitely go back down the ram setting, though, I have tested the memory out separately and found the above setting to be memtest stable for 20+ hours.

I am bit worried about the voltages that I am using though, I am not using any extra cooling on the NB besides the ones provided, and unlike my Q6600 system I am playing it safe this time :P

[Clunk]

It's not a problem, but the other chap's thread had already been hijacked once

Yes, your system specs are showing up now.

Have you tried my 4Ghz settings from the X38 review thread?

Obviously the vcore will be dependant on your own CPU, but you *should* be able to get away with stock VTT, SB/PLL and only minimal NB voltage increase.

About the RAM...Are you stable with the strap at 333/667? If so, it's most likely the RAM not playing nicely on the 333/800 strap

[lethial]

I need to read through the X38 review thread more carefully. I thought the settings in there were primarily for Q6600s, but I didn't get a chance to go through all the pages yet.

I will experiment a little more with RAM settings too, though the RAM was stable at 300/800 when I was testing MAX RAM setting. Though I tested it some time ago, so maybe I should check again.

I will report back.

Aside: nice new avatar Clunk, finally tamed the new intel chipsets have you? Time to smash records?

[Clunk]

There are some E8400 settings in there, page 2 or 3.

I dunno about taming them...trying to understand them is enough

[lethial]

Update: After I tweaked the GTL REF voltage to 63% the system is now very stable... 28 hours of prime and witcher running stable...

Never thought that a little change in GTL could make this much difference... Actually I don't really know ow to interpret the finding... should I drop the vcore some more? I would really like to know why the sudden change of stability?

[Clunk]

It seems to be the luck of the draw, in so much as both of my 45nm CPUs run perfectly on 67% GTL (see CPUZ in sig), which is what the board defaults to with GTL REF voltage disabled.

GTL REF tweaking is highly CPU and board dependant, so what works for one, won't work for another, and then there's getting the VTT right...Anyway, glad you sorted it

[lethial]

Thanks for all the help! I'd love to learn what this whole VTT and GTL REF thing really is... Seems like such a voodoo :P

Maybe now I will go tighten up that RAM timing! :P Nah, I think I will enjoy some gaming first.

[Clunk]

Yep, if it's stable, leave it alone