UD3P / E8500 C0 / 4x1GB D9GMH OC trouble

[Allubz]

Hi there,

I recently switched over from a Maximus Formula x38 @ Rampage x48 to the EP45-UD3P.

Today's overclock-day so here's a little worklog. Any input is very welcome.


The full system specs are in my signature, but we're dealing with an E8500 C0 here.
The RAM was capable of something remotely stable on 1200-5-5-5-18 4x1GB. I'm aiming at <=DDR2-1200.

I'm looking at getting the maximum out of my RAM while maintaining the highest stable CPU OC.

I consider "stable" roughly 5 minutes of OCCT testing. After such stability I move on to the next step, until instability shows up, then I back off and start long-term testing.

DRAM 1:1, 2v (should suffice up to DDR2-1050/1100 on loose timings)
LLC: Disabled
BIOS: F9

4.0GHz stable: (no tweaking or finetuning voltages)
9x445
vCPU: 1.4v (1.34 Win)
vTT: 1.3v
ref: 0.848v
PLL: 1.59v
vMCH 1.2v
ref: 0.783v
DRAMref: 0.91
ICH I/O: 1.59v
ICH Core: 1.2v

4.2GHz stable: (no tweaking or finetuning voltages)
9.5x443
vCPU: 1.475v (1.44v boot, 1.4v load Win)
vTT: 1.3v
ref: 0.848v
PLL: 1.59v
vMCH 1.2v
ref: 0.783v
DRAMref: 0.91
ICH I/O: 1.59v
ICH Core: 1.2v


4.3GHz UNSTABLE:
9.5x453
vCPU: 1.525v (1.47v boot, 1.44v load Win)
vTT: 1.3v
ref: 0.848v
PLL: 1.59v
vMCH 1.2v and 1.3v
ref: 0.783v
DRAMref: 0.91
ICH I/O: 1.59v
ICH Core: 1.2v


4.4GHz UNSTABLE:
9.5x464
vCPU: 1.55v (1.5v boot, 1.47v load Win)
vTT: 1.3v
ref: 0.848v
PLL: 1.59v
vMCH 1.3v
ref: 0.783v
DRAMref: 0.91
ICH I/O: 1.59v
ICH Core: 1.2v

Note: vTT 1.3v OCCT 15 secs. vTT 1.4v OCCT 3 secs.
Note2: Temperatures are always fine. Load on 4.4GHz is 65c


Any input on the 4.2GHz+ settings is more than welcome.


On to setting RAM settings:

My Maximus needed the following voltages for the following frequencies to be remotely stable:


Using the 4.2GHz template (9.5*443) with a lower multiplier.
MCH/DRAM Ref: Auto
DRAM Term: Auto
Channel A/B: Auto
DRAM Drive Strenght: 1066MHz
BIOS: F4

POST - Boot - OCCT (Unstable, 10sec))
Strap: 2.66D
Speed: DDR2-1181-5-5-5-18
Volt: 2.24v (2.21v win)
MCH: 1.3v
PL/TRD: Auto

POST - Boot - OCCT (Unstable, 1:30min)
Strap: 2.66D
Speed: DDR2-1181-5-5-5-18
Volt: 2.28v (2.21v win)
MCH: 1.3v
PL/TRD: Auto

POST - Boot - OCCT (Unstable, 15secs)
Strap: 2.66D
Speed: DDR2-1181-5-5-5-18
Volt: 2.28v (2.21v win)
MCH: 1.4v
PL/TRD: Auto

POST (Unstable)
Strap: 2.66D
Speed: DDR2-1181-5-5-5-18
Volt: 2.30v
MCH: 1.3v
PL/TRD: Auto

So, as it seems my UD3P doesn't like it when I up the voltage of my RAM, which I think is really odd. If anyone can give me info on this it'd be much appreciated!


edit:
signature doesn't show up for this post yet, so here it is:
.ultraV
AC Ryan Acrylic Black Case
Zalman Z600-HP
Gigabyte GA-EP45-UD3P F8
Intel E8500 C0
Team Xtreem PC2-6400(Micron D9GMH)
GeForce 6600GT 128MB
2x Western Digital Caviar 250GB 16MB
Lots of UV-purple case fans and cold cathodes
Pink water cooling - silly!

[Psycho101]

Re: UD3P / E8500 C0 / 4x1GB D9GMH OC trouble

Does the CPU have a known good maximum frequency and Vcore requirement? If you've gotten over 4.2GHz with it before than RAM is likely to be the cause of instability.

Tweaking Driving Strength, sub timings and Static tRead in particular is helpful. I have manaed to squeeze ~30 real MHz (DDR-60) extra out of a set of XMS2 PC2-6400C5 (Ver 4.1, Samsung I believe) above it's current overclock, which isn't the best clocking stuff ever, by tweaking driving strength.

You may also find the 2.66 multi on the C strap may yield more stable results. For example I can't even boot with 2.66D at the settings in my sig, but 2.66C works just fine, as does 2.50A.

As I'm sure you're aware, upping VDIMM will also increase MCH/DRAM, DRAM Ref and Channel a&B ref. Default scaling is 50% of VDIMM, but you may have luck with more or less. As with adjusting CPU and MCH ref, if you temporarily set 1.8V VDIMM, then set the relevant refs to 0.9, then alter them up or down, they will scale correctly when VDIMM is increased.

[Allubz]

Re: UD3P / E8500 C0 / 4x1GB D9GMH OC trouble

Thanks for responding.

4.2GHz runs fine. I find it odd that I can't get 4.3-4.4GHz stable on sub 60c load temperatures.

It is hard to set those references right if I don't know which way to go, as in, higher or lower. On Auto I suppose the DRAM references are at 50%. I can still fiddle with these settings, though.

I'm using the Anandtech article on straps and timings, but it's hard to understand and it's not always too accurate, I found out using my Maximus.
AnandTech: ASUS ROG Rampage Formula: Why we were wrong about the Intel X48

An official reply on how these DDR voltages work would be nice. My Maximus allowed me to set 2.5v no problem, so I'm a bit annoyed that the UD3P doesn't "just" set 2.4 when I want it to, but maybe that's my fault ;)

[gampamu]

Re: UD3P / E8500 C0 / 4x1GB D9GMH OC trouble

Allubz, I have 4x1G Kingstons on UD3P and 1.2V is all I need to run 'um at 1200. I believe you may be experiencing multiple instability issues at 443x9.5 that is obscuring your memory oc results. May I suggest testing the memory at around 360x9.5 using the 3:5 divider (3.33D multi) first and then move on to FSB and CPU overclocks with appropriate PL adjustments.