When XMP is enabled the computer does not wake from sleep.

[Denis_K]

Hi All!

I have built a new Skylake based pc.

The motherboard is a Gigabyte GA-Z170X-Gaming 5, the processor is the i7-6700K and the memory is the Corsair Vengeance LPX 2x8GB DDR4 3200MHz Kit (CMK16GX4M2B3200C16).

I have RMA'd the motherboard because the first one I received was most probably faulty. Also, the memory seems to be working fine; please see below.

I am experiencing a somewhat annoying problem when XMP is on:

1. When I put the computer in Sleep, it does not wake up. More specifically, when I try to wake it up, it seems to be working (all lights, fans are on), but nothing shows on the screen. The reset button does not respond and I have to turn the PSU off and on again. When I do that, the system boots just fine.
Of course, when XMP is off, everything works as it should be.

2. The same thing happens when I shut down the PC. Specifically, when I turn it on pressing the power switch on the front of the case, it seems to be working (all lights, fans are on), but nothing shows on the screen. Again, I have to turn the PSU off and on again and when I do that, the system boots fine.

Additionally, apart from the above (when the system boots normally), the system is super stable, no problems, everything running smoothly (I have also stress tested the system and every test has passed).

I would appreciate your help!

Thanks!

Denis

 

[Tradesman1]

Do you have the latest BIOS and mobo drivers?

 

[Denis_K]

Do you have the latest BIOS and mobo drivers?

Of course, everything is updated to the latest versions.

 

[Tradesman1]

Any OC on the CPU? might need a slight voltage increase to pick up and get going with the 3200 sticks

 

[Denis_K]

Any OC on the CPU? might need a slight voltage increase to pick up and get going with the 3200 sticks

No CPU overclocking at all. Everything is stock. If I need to change any cuatom bios setting, I would really appreciate a brief guide.

 

[Tradesman1]

When running DRAM at the higher data rates a CPU OC is often needed, sounds like your rig runs fine with the CPU at stock but to have the power to pull out of sleep it might need the OC, try going in the BIOS and simply raising the CPU multiplier up 3

 

[Denis_K]

When running DRAM at the higher data rates a CPU OC is often needed, sounds like your rig runs fine with the CPU at stock but to have the power to pull out of sleep it might need the OC, try going in the BIOS and simply raising the CPU multiplier up 3

Thanks. I will try that now and post back to report!

 

[Tradesman1]

Will be in and out, sigh, like always

 

[Denis_K]

Will be in and out, sigh, like always

No prob, of course. So, I did what you suggested (increased the CPU multiplier from 40 to 43) and look what happened:

1. Wake up from sleep is the same as before, no change.
2. When I shut down the PC and the press the power switch, it powers on for less than a second and then goes off. Then, I have to turn PSU off and on again in order for it to boot.

What is your opinion? If it is the motherboard again, probably I will go with another brand.

 

[Tradesman1]

This latest may simply be it needs more vCore 9CPU voltage) can try it at 1.2 (perfectly safe)

 

[Denis_K]

This latest may simply be it needs more vCore 9CPU voltage) can try it at 1.2 (perfectly safe)

Also did that.
Apparently, you were partially correct.
What is actually happening (I had to experiment a bit in order to figure it out) is that when multiplier is increased (with or without an increase to vCore), the system RANDOMLY chooses either to start or not to start, after shutting it down or putting it to sleep.

Any ideas?
By the way, many thanks, you have given a lot of clues here...

 

[Denis_K]

So, after some time experimenting with different settings, at the same time learning about the functionalities of the different voltages that can be adjusted from BIOS, I ended in the following setting:

DRAM Voltage: 1.4V
CPU Vcore: 1.35V
CPU Clock Ratio (Multiplier): 43 (4.3 GHz)

Under this configuration, the system is perfectly stable so far. It also succeeds in sleeping and waking up and it shuts down correctly. Plus, now the system is slightly overclocked at 4.3 GHz.

Dear Tradesman1: Is the above configuration safe? Is it going to affect the life of the processor?

I read somewhere (I think in this forum) that the above value for the CPU Vcore is the "maximum safe" setting. Is that correct?

Thanks a lot!

 

[Tradesman1]

Looks good, as far as the vCore, yes, it's considered 'safe'. How are the temps?

 

[Denis_K]

Looks good, as far as the vCore, yes, it's considered 'safe'. How are the temps?

Temps are as follows:

Idle 24 C
Under full stress 56 C

My cooler is the Cryorig H7 and the fan never reaches 1000rpm. Most of the times, at normal operation, it is at around 650prm.

By the way, what about the DRAM voltage being 1.4V. Should I lower it to the nominal value 1.35V?

 

[Tradesman1]

Take it down and see how things go

 

[Denis_K]

Take it down and see how things go

I did that also. 1.36v works also great (BIOS setting comes only in increments of 2. So I could pick either 1.34v or 1.36v).

Everything runs normal and quiet.

 

[Tradesman1]

Great

 

[Denis_K]

Great

Thanks so much for your help. You have really opened my eyes!

 

[Denis_K]

An important update for anyone using this motherboard:

There is a new BIOS update, version F5e (still in BETA though), which solves the problem completely, at least it worked perfectly for me!

Sleep and shutting the PC down work out of the box with XMP enabled, WITHOUT any CPU overclocking!

By the way, I have changed the Corsair kit with the slightly better G.SKILL F4-3200C16D-16GTZ DDR4 2x8kit and it works flawlessly, although this kit is not in the QVL!

Plain and simple, the system is super stable, for anyone interested.

 

[Tradesman1]

Thanx for sharing that