I've got a set of corsair 8500c5d memory that has been working well so far. I'm running it in an evga 680i and after flashing a bios I get the c1 post error if the voltage hasn't been manually set. To get around this I end up using just one stick to make it boot. However, the odd thing is that only one of my two sticks will boot at the default voltage(1.85v?). The other stick refuses to boot until it recieves 2.25v or greater. After that it runs completely fine. When this memory was new I don't recall having a problem booting them both at default voltage, until I could get into bios to change them to 2.2v. Any ideas why this one stick now wants more power to operate? The other one doesn't exhibit this issue. Both are memtest stable.