Question on effects of dead memory

I seem to have a dead stick of brand new G.Skill memory. Having tested them in sequential order of three for tri-channel, one set shows 12-GB in BIOS and the other 8-GB in BIOS, though when using all six sticks only 16-GB shows up in BIOS. So I am wondering if that is normal, i.e., when one stick is dead then the another stick will not be counted by the BIOS for use or does this indicate another problem?

Is it set to dual-channel? It may be killing a whole channel because of the single module. See if you get 20 GB in single-channel mode.

EDIT: Or not. Not sure how tri-channel would not kill TWO modules... Have you tested each stick individually? What's the point of testing three sticks at a time? That won't tell you anything.

+1 test one stick at a time.

With all six DIMM slots populated, and the DRAM voltage and timings manually adjusted, try adjusting the CPU VTT voltage from Auto to +100mV to start. Default VTT is 1.20V, so adding 100mV is 1.20 +.100 = 1.30V. You may need to go higher than that, somewhere in the neighborhood of 1.40-1.45V (+200-250mV). Just make sure the VTT is within 0.5V of the DRAM voltage, for example setting the DRAM voltage to 1.65V requires the VTT to be at least 1.15V (1.65 - 1.15 = 0.5V). If all the RAM still isn't recognized even w/ the VTT at 1.45V, then remove the CPU and check for bent pins. And when re-installing the HSF, make sure you don't over-tighten it. Also create a sig. w/ your complete system spec's, so we know what you're working with.

Well if I test 3 4GB sticks in slots 1, 3, and 5 and they show up as 12Gb and then I test the remaining 3 sticks in those same slots and those show up only as 8Gb, doesn't that indicate that one of the latter is non-functioning?

How or where do I check in the BIOS for how many channels are running and what is the name of the voltage to check for (these ideas did not even occur to me, thank you)?

UPDATE: I tried doing them one at a time and the PC would not boot. So I then did three at a time to check for 12-Gb, then I pulled out the last one and tried another, only once BIOS showed 8-Gb, so I found the exact dead stick. So I will be sending them all back RMA in the next few days.

Also to note, I know all the rows are working, because I am presently using my 6x2Gb sticks from my old Dell XPS and am showing all 12Gb.

Let us know how it goes when you get your new memory kit.