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Seom question about new Intel deep sleep modes (c6/c7)

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July 5, 2013 1:42:43 AM

Hello guys,
After updating my main system (Q6600+DDR2) to i7 3770k, I am planning to upgrade my secondary system (X4 965 + DDR3).
I am planning only to replace the mobo and processor. The path I am planning to go is Haswell.
I intend to get H87 + i7 4770. No OC and will use the iGPU.
The rest of the old system, I will keep, this includes my old Corsair VS450W PSU.
In Corsair website, the compatibility (C6/C7 mode) is still said to be being checked but I see no update on the list...it means the compatibility is still unknown...yet, I want to order the stuffs latest end of next week.
I know that the C6/C7 is deactivated by default and most probably I will not need those modes.

I am however simply being curious:
What will happen if I activate those modes in BIOS but the PSU is unfortunately not compatible?
Anyone can tell me? I would be very grateful :) 

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July 5, 2013 2:20:35 AM

this was Corsair's reply to an email seeking comment on this issue
"According to Intel's presentation at IDF, the new Haswell processors enter a sleep state called C7 that can drop processor power usage as low as 0.05A. Even if the sleeping CPU is the only load on the +12V rail, most power supplies can handle a load this low. The potential problem comes up when there is still a substantial load on the power supply's non-primary rails (the +3.3V and +5V). If the load on these non-primary rails are above a certain threshold (which varies by PSU), the +12V can go out of spec (voltages greater than +12.6V). If the +12V is out of spec when the motherboard comes out of the sleep state, the PSU's protection may prevent the PSU from running and will cause the power supply to "latch off". This will require the user to cycle the power on their power supply using the power switch on the back of the unit."
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July 5, 2013 2:37:53 AM

ah...ok...did I understand it correctly?
"The PC cannot be waken up from sleep mode/ restarted unless I turn the PC off completely first (cold boot).
I think...This is not really critical, I could simply try it 1 or 2 times and if I see something like that, I have simply to go to BIOS and deactivate the C6 and C7."
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