Hitting walls when OC'ing GTX 470s

[xbonez]

I have an ASUS GTX 470 (stock cooler), and a EVGA GTX 470 with a Zalman V3000f cooler.
Both cards have been flashed with a custom BIOS to permit higher voltages than the standard 1087mV limit.

Asus GTX 470:

Runs furmark stable at Core: 770Mhz, Memory: 1700 Mhz @ 1070 mV.
Furmark cannot push temps above 82 degrees.
Folding overnight keeps temp at about 70 degrees.

From this point on, any increase in clocks causes me to lose display within 3min of Furmark. I've tried pushing more voltage (upto 1200 mV). Temps are well within the threshold of 105 degrees (though I would not run it at anymore than 90-92 degrees)

EVGA GTX 470 with Zalman Cooler

Furmark stable at Core: 825, Memory 1800 Mhz @ 1100 mV.
Furmark cannot push temps above 75 degrees.
Folding overnight keeps temps at late 50s.

Any further OC either causes me to lose display during furmark, or the card crashes during 3D Mark vantage, or return errors during folding (UNSTABLE_MACHINE).
Tried pushing more voltage, but to no avail. Temps are well within control.

With both cards, I'm hitting a wall I cannot explain. The cards are not limited by temperature, nor voltage. How can I push the clocks further?
If there is nothing I can do, I don't get the point why people water cool GPUs when in all cases I'm not being limited by temps. Do I need to OC something else for stability? maybe northbridge, or something?

I'm running a Phenom II x4 965 on a MSI 790FX-GD70, everything at stock.
2x2Gb GSkill Ripjaws 7-7-7-24 @ 1333Mhz.

 

[borisvodofsky]

I have an ASUS GTX 470 (stock cooler), and a EVGA GTX 470 with a Zalman V3000f cooler.
Both cards have been flashed with a custom BIOS to permit higher voltages than the standard 1087mV limit.

Asus GTX 470:

Runs furmark stable at Core: 770Mhz, Memory: 1700 Mhz @ 1070 mV.
Furmark cannot push temps above 82 degrees.
Folding overnight keeps temp at about 70 degrees.

From this point on, any increase in clocks causes me to lose display within 3min of Furmark. I've tried pushing more voltage (upto 1200 mV). Temps are well within the threshold of 105 degrees (though I would not run it at anymore than 90-92 degrees)

EVGA GTX 470 with Zalman Cooler

Furmark stable at Core: 825, Memory 1800 Mhz @ 1100 mV.
Furmark cannot push temps above 75 degrees.
Folding overnight keeps temps at late 50s.

Any further OC either causes me to lose display during furmark, or the card crashes during 3D Mark vantage, or return errors during folding (UNSTABLE_MACHINE).
Tried pushing more voltage, but to no avail. Temps are well within control.

With both cards, I'm hitting a wall I cannot explain. The cards are not limited by temperature, nor voltage. How can I push the clocks further?
If there is nothing I can do, I don't get the point why people water cool GPUs when in all cases I'm not being limited by temps. Do I need to OC something else for stability? maybe northbridge, or something?

I'm running a Phenom II x4 965 on a MSI 790FX-GD70, everything at stock.
2x2Gb GSkill Ripjaws 7-7-7-24 @ 1333Mhz.

There are cases where 2 different coolers produce the same temperature on the same card, yet, one cooler lets the card OC higher..

But, at 75C on that card you ARE infact having heat issues.

Also, overvolting usually requires seperate VRM cooler, do you have 2 of those? BTW (if you're using little square mosfets to cool vrm) stoppp they're a joke, FIT is everything here, cuz their surface is so small.

You need to get some sort of vrm cooler that was made specifically for the 470,,

These cards should ideally be around 60 tops for high overclock

 

[xbonez]

Why is it a heat problem at 75, when these cards are rated to have a threshold temp of 105 degrees by nVidia? I'm a good 30 degrees short of that.

Also, yeah...I am using heat sinks. The ones that come with the Zalman cooler. Whats a good utility to monitor VRM temps?

 

[OCGuy]

75C is NOT a problem on a GPU.

 

[Martimus]

There are cases where 2 different coolers produce the same temperature on the same card, yet, one cooler lets the card OC higher..

But, at 75C on that card you ARE infact having heat issues.

Also, overvolting usually requires seperate VRM cooler, do you have 2 of those? BTW (if you're using little square mosfets to cool vrm) stoppp they're a joke, FIT is everything here, cuz their surface is so small.

You need to get some sort of vrm cooler that was made specifically for the 470,,

These cards should ideally be around 60 tops for high overclock

?

Do you know what a MOSFET is?

It is a transistor, it sure as heck isn't a heat sink. In fact, I can't imagine how you could mistake the two. Functionally and Physically they are completely different things.

 

[xbonez]

?

Do you know what a MOSFET is?

It is a transistor, it sure as heck isn't a heat sink. In fact, I can't imagine how you could mistake the two. Functionally and Physically they are completely different things.

Lol...thanks for clearing that up. I assumed by mosfets, he meant heat sinks. later I was wiki'ing it, and I was completely confused.
I'm editing my post to reflect the correction.