Cant dual-channel in Asus Z170

Hi guys,

 

I've searched Google and this forum extensively for any potential solutions, but couldn't find something specifically pertaining to my RAM and this mobo.

 

I have an Asus Z170 Pro Gaming motherboard, and Corsair DDR2400 8GB RAM (2x modules, so 16GB total). The part number of the RAM modules are CMK8GX4M1A2 400C14.

 

So here's what's happening:

 

1) If I put the RAM into slots 4 and 2, the PC doesn't POST.

2) If I only put one module into slot 4, it POSTs fine.

3) If I put one module into slot 4 and another into slot 3, it POSTs fine, but is obviously single-channel.

 

When it does POST, the mobo sees the RAM at 2133MHz. I then have to enable XMP to get it up to 2400MHz (and that works fine).

 

What I've tried:

 

I tried putting in only 1 module into slot 4. The PC POST'ed, and I went into the BIOS and enabled XMP for 2400MHz. I then rebooted, and shut down. Put the second module into slot 2, and started up the PC again. But again, no POST.

 

Some people suggest I do the following:

 

Put in only one module into slot 4. Get into the BIOS, and disable XMP and set it to manual. Then set the speed and timings manually, reboot, power down, and install the second module into slot 2.

 

I'm not sure if that would work, but regardless - I have no idea what timings etc to fill in there, and absolutely no idea what voltage. Can anyone help me out there? Or does anyone know of any other way to get these modules to run in dual-channel?

 

EDIT: My BIOS is on the latest update (1805)

With XMP disabled what happens with just a single DIMM in each of slot 1 and then slot 2?

With XMP disabled what happens with just a single DIMM in each of slot 1 and slot 2?

With XMP disabled, and the DIMMs in slots 1 and 2, it's single-channel at 2133 and POSTs fine.

 

With XMP disabled, and the DIMMs in slots 4 and 3, it's single-channel at 2133 and POSTs fine.

 

With XMP disabled, and the DIMMs in slots 4 and 2, it doesn't POST at all.

 

With XMP disabled, and the DIMMs in slots 1 and 3, it doesn't POST at all.

Strange. What about 1 + 4 and 2 + 3?

 

The manual names the DIMM slots A1 + A2 + B1 + B2. Use the correct names!

Strange. What about 1 + 4 and 2 + 3?

 

The manual names the DIMM slots A1 + A2 + B1 + B2. Use the correct names!

I haven't tried 1+4 and 2+3, but would assume it would have the same result. However, I'll try tonight when I get home.

 

I'll use the correct names, thank you. So far, my "translation" has been:

 

Slot 1: A1

Slot 2: A2

Slot 3: B1

Slot 4: B2

With just one DIMM you should use A2. Does the system post with just one DIMM in A2 for both DIMMs?

A2 or B2 worked for me with 1 DIMM. Tested both DIMM's separately, yes.

Actually no, on further investigation and testing I found that only B1 and B2 work. A single DIMM works in either B1 or B2. Two DIMMs work together in B1+B2 in single-channel mode.

 

But nothing works in A1 or A2. Not a single, no doubles, nothing. Those 2 slots are completely dead. But not dead as you would normally expect from bent CPU socket pins or something.. the computer physically does not POST if you put ANYthing in either A1 or A2.

 

(Did check for bent CPU socket pins, btw, they're all fine. Air cooler also isn't on too tight or anything)

I guess there must be either an issue with the motherboard or CPU and suspect the only way to know which is to try your CPU in a known good motherboard or a known good CPU in your motherboard.

I guess there must be either an issue with the motherboard or CPU and suspect the only way to know which is to try your CPU in a known good motherboard or a known good CPU in your motherboard.

Of which I unfortunately have neither on hand, but I can live with single-channel for now. Talking to ASUS as well regarding the mobo, would be interesting to see if they can RMA or if they are going to blame the CPU or the RAM.

 

Maybe the latest BIOS is the issue, I'm not sure. Hope it's only that.

they are going to blame the CPU or the RAM.

 

I can't see how it can be the RAM as the DIMMs work in B1 + B2 but not in A1 + A2.

 

I also think it's unlikely to be a BIOS issue otherwise all boards would have this problem.

I can't see how it can be the RAM as the DIMMs work in B1 + B2 but not in A1 + A2.

 

I also think it's unlikely to be a BIOS issue otherwise all boards would have this problem.

True, although there does seem to be alot of issues with this particular board (or well, all the Asus Z170's) and RAM with every new BIOS update. Google heaps page upon page of results on me when I search for this issue. Problem is, no 2 problems seem to be completely identical and none of the solutions worked for me (mostly regarding setting the RAM freq, voltages and timings manually).

I've signed up here just to reply to this. I have this exact same problem with G.Skill F4-2133C15D-16GRR with Z170 Gaming Pro and can't find a solution.

 

Only works in B1 and B2. Any ram in A1 or A2 whether 1 or 2 refuses to POST. XMP always shows up as disabled.

 

With B1 and B2 according to UserBenchmark MultiCore read and write are half of what they should be, I assume because it's single channel and not dual which makes sense because the timings are the same if I benchmark a single stick.