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Missing voltage options? P8Z77-V LK

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July 26, 2012 10:47:12 PM

Here's the difficulty I'm having. on my board, I can't find the QPI/VTT/IMC or equivalent voltages. I'm running my RAM at 1.7v, and I need to know if I'm going over the .5v potential difference limit, and to adjust voltages accordingly.

But I really can't find this option. It's like it exists on every other board, but is disabled on mine. WHat's up with that?
a c 1101 V Motherboard
July 26, 2012 11:02:47 PM

You know about the 1.5 ram limit on the LGA1155 platform.
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July 26, 2012 11:27:55 PM

You mean the default VTT of 1V? and thus the consequent RAM limit of 1.5v? yes. But is it not a standard feature to be able to raise the VTT/IMC to something like 1.2v to raise the RAM to 1.7v? My RAM is still running at room temperature so there's more OC room.
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a c 1101 V Motherboard
July 27, 2012 12:27:50 AM

All I have found in my BIOS is that I can raise the ram voltage itself under ram voltage. If you look in your manual BIOS/UEFI section they warn against going over 1.55volts because it can damage the CPU, nothing to do with the temp of the ram.
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August 3, 2012 4:04:19 AM

Yes.

The reason they recommend against the 1.55 volts is because it exceeds the 0.5v limit between the VTT voltage and the DRAM voltage.

Too large of a potential difference between RAM voltage and vtt/IMC voltage will cause too much back current against the diodes and transistors, causing breakdown and leakage, leading to a lower life expectancy of the CPU

I knew this going in. That's the whole reason I posted this in the first place.

I want to raise my vtt voltage so I can raise my RAM voltage, so that I can take advantage of the temperature headroom.




Let me repeat....

1.0v + 0.5v = 1.5v

1.55v > 1.5v : Not good

I want around 1.7v.

1.7v - 0.5v = 1.2v

So I'll need around 1.2v vtt/imc

In order to raise my vtt, I need to change the option in the BIOS.

Most people with motherboards in this series have the option.

I don't.

I'm on here asking why. If there a hotkey I'm missing, or if there was a BIOS update that removed it.
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August 10, 2012 11:13:30 PM

I seem to have found the issue. According to other forums and other information, the VCCSA is associated with VCCIO. So my raising the VCCSA, the VCCIO offsets by the same amount.


I've tested it, and speedfan doesn't report much of a change, though.
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