Intel D975XBX2 Overclocking Problems!!!

[Surgeon]

I'm just really getting into overclocking on my new system and really need some expert's help to figure out what I'm doing wrong... Please...

First, my system configuration consists of the following:

Intel D975XBX2 Motherboard (Rev 504 with latest BIOS v2674)
Intel E6600 2.40GHz Core 2 Duo Processor (Conroe Stepping B2)
Zalman CNPS9700 NT Heatsink (with double mounting brackets)
Kingston KHX6400D2LLK2/2G DDR2 2x1GB HyperX Memory (800/4-4-4-12@1.96v)
4 Maxtor 7H500F0 500GB SATA2 Hard Drives (on Intel controller in native mode)
2 NEC/Optiarc AD-7170A DVD Writers (on IDE bus)
ATI X1950 Pro 256MB PCIE-16X Video Card
ATI TV Wonder 550 PCI Tuner Card
Antec P160W Aluminum Case
Antec 120mm case fans front & rear
Ultra X-Finity 500W Power Supply
Microsoft Windows XP-Pro SP2 (fresh install with all updates)

In the BIOS I've disabled C1E, the Watchdog Timer, and EIST
and XP's power setting is set to "Always On".
With the BIOS's Memory Frequency set from 800 down to 533, and the CPU Settings set to the out-of-the-box Intel defaults as:

CPU Voltage Override: Default
Enhanced Power Slope: Disabled
Front Side Bus Voltage Override: 1.250
MCH/ICH Voltage Override: 1.575
I can then raise the Host Clock Frequency from 266MHz up to 360MHz and obtain a rock-solid 3.24GHz system that idles @ 39° and climbs to 60° max under Intel's Thermal Analysis Tool (TAT) running both cores at full bore for over an hour. (I've tried several other CPU Stress utils and find that TAT gives me the highest under-stress core temperatures. -- Also note that every util I've found reports different core temps, so I use the readings from Intel's Desktop Control Center (IDCC) because it always shows the highest temp values.) Going up to 370MHz always results in various "crashes" after 10-20 minutes of the full-bore stress testing. (But the temp still never climbs above 60°.) I've tested it overnight with various utils and it never misses a beat @ 360MHz.

Now I feel going from the base 2.4GHz -> 3.24GHz with a 60° max temp is pretty decent for all-stock CPU voltages, but, like everyone, I want more... :D

BUT TRY AS I MIGHT I CAN'T FIND ANY MORE!!! :confused: :confused: :confused:

The first problem I encountered is that Everest/CPU-Z/PC Wizard 2007 all still show that C1E and EIST are *still* active, even though they show as disabled in the BIOS! (It's like XP-SP2 is turning them back on, but does anyone know why???) I've tried all the various XP power settings but they still always show up as active.

So, to solve this I run RM Clock to re-disable C1E and EIST on each boot. I then verify that they are "truly" disabled using Everest. Then I try raising the BIOS's CPU voltages. I've tried lots of various combinations ranging all the way up to:

CPU Voltage Override: 1.5
Enhanced Power Slope: Enabled
Front Side Bus Voltage Override: 1.375
MCH/ICH Voltage Override: 1.675
But no matter what I set the CPU voltages to, the max I can run stable at is still the same 360MHz!!! Even though the temp doesn't ever climb above 60° with the higher voltage settings, the system still always crashes on anything above 370MHz.

I'm completely confused! I thought that the whole ideal of raising the CPU voltages would let me climb above what I can obtain with the stock settings... I've even tried raising the memory's voltage up to 2.06v and lowering it's timings to 5-5-5-15, but that also has had no effect...

Can anyone *please* tell me what I'm doing wrong??? (Also, can anyone point me to a util that will show the "true" active CPU core voltage?)

Thanks so much!
-Surgeon-

[mezcal]

Well, I'm no expert but...
The bx2/c1e bug is well documented and discussed to death in the giant bx2 thread.
What strap are you on (ref freq?) It is very easy to massively overclock ram on the bx2 (it likes to reset to it's preferred values when you aren't looking.)
Also, there's a fair amount of discussion re the voltage changes set in bios not actually working until you power the system completely down. Since you're using everst I assume you've already checked that out though.
TAT is what I use for temps also. Coretemp 0.95 reads similar. There are also a ton of threads regarding this issue all over XS and elsewhere.
And hey, 3.24 ain't bad :toast:

[gtj]

If you're using the latest version of Everest then that's the best all around monitoring program out there.

If you ahven't already, check the guide in my sig. You may find something useful there.

[Surgeon]

mezcal & gtj

Thanks so much for the help!

The problem ended up being that I was only powering-down the system via the front panel when I changed voltages, when I should have been fully turning off the system using the power-supply's switch... My bad... :rolleyes:

That said, I find that I'm still going have to be contented with the 360MHz/3,24GHz settings with default voltage levels. Even though I can now get to a stable 380MHz/3.42GHz, to do so requires a sizable voltage increase (CPU 1.225 -> 1.500v) and the additional heat generation (60° -> 72°) worries me too much. This is my "daily driver" machine and as such dependability still remains my paramount concern.

gtj, did you know that your 975XBX2 Bad Axe 2 Guide page is a *great* source of well thought out information? :banana: A really well done site! :clap:

One final question concerning memory speed if I may... How does the wait-state timings affect the "memory calculator's" results? I mean, would one achive more "real world" throughput with a DDR2 rate of 850MHz @ 5-5-5-15 or 750MHz @ 4-4-4-12?

Thanks again!
-Surgeon-

[gtj]

Sounds like you're at a good place right now. Thanks for the comments on the guide.

It's hard to tell what the "real world" difference would be because our real worlds are all different. From a benchmark perspective, the extra 100 MHz is going to give you an edge. From an application perspective, I honestly don't know.

[lad]

Surgeon, I've found Speedfan to give reliable core and other mobo temp readings on 6600/xbx2.

To keep temps low, you must have great case airflow. Consider cutting out the perforated areas in the case (the fan cutouts).

A TAT load is a great way to really testntune your cooling, but if you can stay under 60c using Orthos small ffts for at least 10 minutes, when your ambient temp is reasonably high, you're at a safe place. (You then need to run Orthos overnight to see if your OC is working *reliably*.)

You might need to increase vFSB and vMCH-I did. I'm at 1.3 vFSB and 1.575 vMCH, and the NB and SB temps are still good-due to massive case airflow with 120x32 Silverstone fans.

You want to keep really good records on what you set, and the test results of those changes.

I'd consider a fan mod to that Zalman. I personally think most of the airflow goes either inside, or outside the finned area, reducing cooling. That's an opinion not based on ownership... FWIW.