can't post with two memory modules installed

[tardis42]

I've been having some system freezing/stuttering issues recently that I suspect might be due to faulty RAM. I've been running a single 8GB stick since its twin died on me last year. Today I removed the old stick and installed two 4GB Kingston HyperX sticks @1600Mhz in slots 2 and 4 of my motherboard. I couldn't boot or even reach the BIOS screen; LED readout on my mobo kept cycling through startup codes and getting stuck at 55, which according to the mobo manual is memory initialization. I figured one of the new sticks might be faulty so I tried booting with just the one in slot 2; the system booted normally.

I then tried swapping the other new stick in on its own and again, the system booted normally. So, thinking there might instead be something wrong with slot 4 on the motherboard, I tried booting with the two new sticks in slots 1 and 3; post failed at code 55 again.

Booting with the two sticks in slots 1 and 2 worked, and the full 8GB was detected in the BIOS, but as I understand it this setup will impact performance as dual-channel mode requires populating either the two odd-numbered or the two even-numbered slots.

I know that a bent CPU pin can cause problems with the memory controller and dual channel function, but I was using dual-channel for a long time and haven't gone near the CPU since the old 8GB stick failed. Is there anything else I should check for?

 

[vegettonox]

Can you post your motherboard model and the model information of your memory sticks?

 

[brispuss]

Yes, for dual channel operation, DIMM's should be inserted in slots 2 and 4, or slots 1 and 3. DIMM's in slots 1 and 2, or in slots 3 and 4 will operate in single channel mode.

It may be that the Kingston DIMM's are just incompatible (in dual-channel mode) with your system.

The two 4 GB DIMM's if they are from the same dual channel kit, then it may be possible to get them to work (in dual channel mode) by increasing the DRAM voltage a bit, and/or increasing memory controller voltage (VCCSA or CPU-NB) a bit in BIOS.

If the two DIMM's were NOT from the same dual channel kit, then the chances of successful dual channel operation is less due to variation in DIMM parameters.

If no success in getting the DIMM's to work in dual channel mode, then could search for compatible replacement dual channel DIMM's at memory manufacturers websites, as most manufacturers have memory search functions.

 

[Tradesman1]

Try clearing CMOS, make sure you have the latest BIOS then try in slots 1-3 from CPU

 

[tardis42]

The motherboard is an MSI Z87-GD65 Gaming. The two sticks I'm trying to use are from the same pack. They're Kingston HyperX Fury 1600Mhz CL10 DDR3, part number HX316C10FK2/8.

Clearing CMOS has no effect. I just updated the BIOS last week.

The mobo is dual-BIOS so for the hell of it, I tried switching to BIOS B (which has never been updated from version 1.0) and it still crashed, although in a slightly different way (current BIOS version repeatedly tries to post and sticks at code 55 every few seconds, older version stops at 55 for about ten seconds and then clicks off).

I've got a pair of Corsair Vengeance 4GB sticks on the way, should arrive Saturday; if they work, I'll return the Kingstons. If not, is it safe to assume this is an unfixable CPU or motherboard problem? Or is there something else I should look at?

 

[Tradesman1]

Couple of things to try, one - try loosening the CPU cooler then snug it back down, it may be too tight in a corner or side throwing the MC (memory controller) off. Another would be to install a single stick in 1 or 2 then raise the DRAM voltage up + 0.05 (to 1.55) in the BIOS, save, exit, shutdown and then add and try the second stick in slot 3

 

[brispuss]

If the Corsair Vengeance 2 x 4 GB memory is either -

this, or

this, or

this, or

this, or

this, or

this, or

this,

then the memory is (supposed to be) compatible with the Z87-GD65 Gaming motherboard.

If the Corsair Vengeance memory ordered is NOT one of the above models, then it may not be compatible with the Z87-GD65 Gaming motherboard.

If by chance the Corsair memory doesn't seem to work, it may be that the memory is faulty, or the memory slots/motherboard is faulty, or maybe both.

Again, minor increase of DRAM Voltage and/or the memory controller voltage may be tried.

Trying one DIMM at a time in different slots will help determine whether the DIMM and/or slot is faulty.

 

[tardis42]

The Vengeance memory is the second-last one in that list, CML8GX3M2A1600C9. Same problem as the Kingston: works in slots 1 and 2, but not 1 and 3 or 2 and 4. Tried loosening and re-tightening CPU cooler and upping RAM voltage, no dice. I haven't tried to tweak the memory controller voltage yet...not sure I even know what that setting's called in the MSI BIOS.

I'm going to assume something on the motherboard is faulty. Planning to upgrade next year so for that time I guess I'll probably have to stick with a single-channel config.

 

[brispuss]

Seems likely that the motherboard is faulty, unfortunately. But at least you can still run it, even though at reduced memory bandwidth.