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Any worthy upgrade for a PII 940BE?

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Dangerous_Dave

Member
Joined
Dec 19, 2009
Hi all,

I made a switch from a Q6600 to a PII 940 BE, not particularly for performance gain, but because it saved me a little money on balance. I'm not sure which wins when they're both overclocked to 3.4Ghz

Is there anything being offered by AMD that is significantly faster than what I have? Is the 965 BE essentially the best they have?

If so, what are safe voltages to apply to my processor with decent aftermarket air cooling? At the moment I'm struggling to hit 3.5Ghz. Should I be tweaking the myriad other voltages that my DFI board lets me interfere with? Maybe fiddling the multiplier?

Cheers
 

Bobnova

Senior Member
Joined
May 10, 2009
The 940 beats the q6600 clock for clock by a decent amount, it ought to go higher then 3.4ghz.
1.5vcore is the accepted max, and temps <60*c (though generally stability takes a dive at 55*c).

The multiplier is the easiest (and arguably best) way to OC a black edition, you don't have to muck with any of the other multis that way.
Unlike Intel's FSB, the HTref really doesn't change the available memory bandwidth or anything else, it's just a reference, there's no benefit from having it higher then 200 (sometimes 200-and-change-x-whatever works better then 200x-whatever for some reason).
Of course on a non-BE it's the only way to OC.

The 965 doesn't beat a 940 clock for clock, they're the same same core, the only thing you gain is a higher base speed (and that the C3 stepping out now OCs further then the C2s do generally speaking).
 

The_Smurph

Registered
Joined
Nov 29, 2008
Alright I can give ya some advice when overclocking that 940. First almost all of the 940's have run up to roughly 3.7-3.8 relatively easy. First off we all want to know what CPU cooler you are using. Temps are key with these chips. My 940(its toasted btw) would run up to 3.75ghz stable. I would recommend keeping voltage below 1.5V. Have you increased your voltage at all?
 
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Dangerous_Dave

Member
Joined
Dec 19, 2009
Hi there,

I believe it's a Zalman CNPS 9500. I've upped the voltage, but only to 1.375 at max. Then it was getting a bit unstable at 3.5Ghz. Just as a matter of interest, why is your processor toast?
 

QuietIce

Disabled
Joined
May 7, 2006
Location
Anywhere but there
:welcome: to OCF!


The first key to OC'ing is knowing the loaded core temperature. To get the load temp you should run Prime95 or OCCT and maybe use CoreTemp to read the temperature off the CPU.
Prime95
OCCT
CoreTemp

If your temp is below 55°C then you're good to increase the vCore (CPU voltage) another step. You should also read through Dolk's Guide. At 3.6 GHz your cpuNB speed should be 2200-2400 MHz to keep everything stable.

Which DFI are you using ...?
 
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Dangerous_Dave

Member
Joined
Dec 19, 2009
I'm using the 790FX M2R. I just read something in the BIOS that might explain my lack of success. It says that for phenoms you need to raise the CPU NB voltage to match the raised CPU voltage. Basically it has 4 CPU voltage options:

1 CPU VID control
2 CPU VID Special Add
3 CPU NB Voltage control
4 CPU NB VID Special Add

I'm not sure what the special add ones are about. Should I just raise 1 and 3 to ~1.4V and see what will be stable?
 
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Dangerous_Dave

Member
Joined
Dec 19, 2009
I tell a lie. Now the fastest that I can get it to run at @ 1.375V is 3450Mhz (230x15). Could it be that I have the worst 940 BE in existence?

This motherboard is some strangeness though. It has a setting for boot up clock separate from the general clock, but it destabilises on boot up for high overclocks.

Anybody got any advice?
 

The_Smurph

Registered
Joined
Nov 29, 2008
I burnt up my memory controller would be the best guess, as that is what I was monkeying around with when my 940 bricked. I also was very unhappy performance wise with my 940 with the setup I had. We need to know temperatures, I will tell you this, I had the 9500 on my old 9950BE and it couldnt dissipate the heat fast enough for overclocking a 140W processor. Let us know temps and we can start to find out where the problems are.
 

QuietIce

Disabled
Joined
May 7, 2006
Location
Anywhere but there
I'm using the 790FX M2R. I just read something in the BIOS that might explain my lack of success. It says that for phenoms you need to raise the CPU NB voltage to match the raised CPU voltage. Basically it has 4 CPU voltage options:

1 CPU VID control
2 CPU VID Special Add
3 CPU NB Voltage control
4 CPU NB VID Special Add

I'm not sure what the special add ones are about. Should I just raise 1 and 3 to ~1.4V and see what will be stable?
The Phenoms, overall, were better with higher cpuNB voltage than the Phenom II's. 1.35v CPU and 1.25v cpuNB should work. As for how to get there, what do the options under both "Specials" look like?

Also, we really do need those load temps to go much farther with advise ... ;)
 

nzaneb

Senior Member
Joined
Nov 3, 2008
I tell a lie. Now the fastest that I can get it to run at @ 1.375V is 3450Mhz (230x15). Could it be that I have the worst 940 BE in existence?

This motherboard is some strangeness though. It has a setting for boot up clock separate from the general clock, but it destabilises on boot up for high overclocks.

Anybody got any advice?

Stop upping the Reference Clock. Set it back to 200, and use the multiplier to increase the CPU speed. Right now you're overclocking your RAM as well. At this point, for the sake of simplicity, overclock with the multiplier only. You'll be able to push it much further, without having to worry about the rest of your components as well.
 

The_Smurph

Registered
Joined
Nov 29, 2008
Yeah you are def at the heat wall with these chips. If you want to get your temps down you should def upgrade your cooler. There are quite a few decently priced coolers out there.
 
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Dangerous_Dave

Member
Joined
Dec 19, 2009
Actually I tell a lie - the processor gets to low 40's, but the chipset gets to 68/75 degrees respectively! Isn't that a bit mad? Could be casuing problems?

Also, the stability of the system depends on which memory slot/slots I use. Is that a returnable defect?
 

QuietIce

Disabled
Joined
May 7, 2006
Location
Anywhere but there
Yes, having a chipset temp that high could be a problem - most chipsets don't run over 50°C. But if you're running caseless with a vertical-mount sink that could do it. You've got almost no airflow over the chipset that way. In the case you should have a rear exhaust fan that will keep some air circulating across the chipset so temps should actually drop in the case.



Guy to a Ford dealer, "Hey, this new Mustang is defective! It's got a 150 MPH speedometer but I can only get it up to 130 MPH! I want my money back!!!" :p
 
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