Memory Can't Reach Spec: 3000 MB/s

[jchunter]

My Corsair memory (cmk16gx4m4b3000c15) is stable at 2800 MHz at stock voltage (1.2v). However, frequencies above that fail immediately with voltage up to 1.3v. I have also tried Memory Profile 1 suggested in the bios setup (3000MHz @ 1.35v) and it also fails immediately. I am wondering if some of the other memory tuning parameters need to be set (eg., Dram Training Voltage, DDRVPP, and DRAM Termination, ...). These are new to me, as are safe max voltage limits, and I need some memory overclocking advice... TIA

 

[EarthDog]

Have you updated to the latest bios on that board (F5)? If not, do so as F5A included an XMP profile compatibility fix.

Have you tried the XMP Profile instead of setting it manually?

 

[jchunter]

Have you updated to the latest bios on that board (F5)? If not, do so as F5A included an XMP profile compatibility fix.

Have you tried the XMP Profile instead of setting it manually?

Yes to both questions.
BTW, when the memory crashes, the mobo usually responds by resetting the bios back to F2. Is there any way to prevent this?

 

[EarthDog]

What?!!! That shouldn't happen... I have never heard of the bios flashing back. Are you certain you flashed it properly to F5? And it shows that on the screen? Post a screenshot of the bios with it showing F5... or CPUz in windows - the mainboard tab.

 

[jchunter]

What?!!! That shouldn't happen... I have never heard of the bios flashing back. Are you certain you flashed it properly to F5? And it shows that on the screen? Post a screenshot of the bios with it showing F5... or CPUz in windows - the mainboard tab.

I am quite certain that F5 was properly flashed. It clearly showed in the bios. I asked Gigabyte Tech support and they replied that happens if the bios becomes corrupted in the crash. I suspect a bios bug that could be overwriting itself... Edit: The board has a dual bios.

 

[EarthDog]

Wow... that's new to me! Weird how it corrupts the bios when using XMP...

You should just have to set 1.35v and the main timings manually and it should work. You can try adding System Agent voltage, but I doubt its needed.

 

[jchunter]

Wow... that's new to me! Weird how it corrupts the bios when using XMP...

You should just have to set 1.35v and the main timings manually and it should work. You can try adding System Agent voltage, but I doubt its needed.

It certainly is weird and also is a PITA because I have to reflash F5 after every failed overclock. I expected new memory to work at rated speed without boosting voltage.

BTW, what is the maximum safe voltage for ddr4 dram?

 

[EarthDog]

1.5v from the Intel spec I believe.

DDR4 3K will more than likely run at 1.35v.

 

[jchunter]

I just tried 2900MHz @ Vmem = 1.36v and it crashed with a "Boot Failure Detected" warning. This time it allowed me restart without rolling back to F2.

 

[ATMINSIDE]

It's very possible you need to up the VCCSA since you're running 4x4GB.

 

[jchunter]

It's very possible you need to up the VCCSA since you're running 4x4GB.

I don't find VCCSA on my bios. What is it also known as?

 

[ATMINSIDE]

System Agent Voltage

 

[jchunter]

System Agent Voltage

I've scanned my ga-z170xp-sli documentation and have found nothing in the bios that would control what seems to be a major power rail. Perhaps it is controlled indirectly thru something else...

EDIT: Two other bios controls that might be the "something else": Power Limit TDP and Core Current Limit. It seems a long shot but the failure smells like a sharp cut off rather than a gradual decline in memory circuit performance...

 

[EarthDog]

Shouldn't be... it's called vccsa or system agent voltage.

Probably in advanced voltage settings...

Edit: it's cpu vccsa.

 

[jchunter]

Shouldn't be... it's called vccsa or system agent voltage.

Probably in advanced voltage settings...

Edit: it's cpu vccsa.

Found it under adv voltage settings! The Gigabyte manual has no detail in this section but the bios has it listed at 1.060v. I took a guess and set it to 1.070v but no joy. 2900MHz failed and dumped me back into bios release F2.

 

[EarthDog]

Set it .15 over stock.. .01 is nothing.

 

[jchunter]

Still no joy... Back to F2 bios. I'm not getting a warm feeling about more voltage. Something else is going on. Maybe I should consider RMA... Suggestions for 16 GB DDR4 ?

 

[EarthDog]

Any reason you need 16GB 8 is plenty for most people.

If you want to make sure it will work 100%, go off their QVL list found on their website.

 

[jchunter]

Z

Any reason you need 16GB 8 is plenty for most people.

If you want to make sure it will work 100%, go off their QVL list found on their website.

I did check the Gigabyte QVL for these specific Corsair memory sticks and got the OK before I ordered them.

 

[EarthDog]

Oy... bad luck my man.