Problem with Strix Z270-F and G.Skill Trident Z RGB 2x8GB @3866MHz

[samuel9521]

Hi All,
I have a problem with my ram, and I hope you can help me.

I bought a Strix Z270-F with an i7-7700k and these G.Skill ram: F4-3866C18D-16GTZR. The problem is that I can't run them at 3866MHz: simply when I set 3866MHz in the BIOS (v. 0906) with the stock XMP profile voltages and timings, the system doesn't boot, and on the mobo the yellow led lights up for some seconds, then it lights off and the screen goes black, and the only thing I can do is turn off the pc through the power button.


Now my system is perfectly stable with this settings:

Ai Overclock Tuner____________________________XMP
XMP__________________________________________XMP DDR4-3868 18-19-19-39
BCLK Frequency_______________________________100.0000
ASUS MultiCore Enhancement__________________Auto
AVX Instruction Core Ratio Negative Offset_____0
CPU Core Ratio________________________________Sync All Cores
Core Ratio Limit_______________________________48
BCLK Frequency : Dram Frequency Ratio_______Auto
DRAM Odd Ratio Mode________________________Enabled
DRAM Frequency______________________________DDR4-3600MHz
TPU___________________________________________Keep Current Settings
EPU Power Saving Mode_______________________Disabled
CPU SVID Support_____________________________Auto
DRAM Timings________________________________15-15-15-36
Internal CPU Power Management
Intel SpeedStep_______________________________Auto
Turbo Mode__________________________________Enabled
CPU Core/Cache Current Limit Max.___________Auto
CPU Graphics Current Limit___________________255.50
Min. CPU Cache Ratio________________________Auto
Max. CPU Cache Ratio________________________45
Max. CPU Graphics Ratio_____________________27
BCLK Aware Adaptive Voltage________________Auto
CPU Core/Cache Voltage_____________________Adaptive Mode
Offset Mode Sign_____________________________+
Additional Turbo Mode CPU Core Voltage______1.205
Offset Voltage________________________________Auto
DRAM Voltage_______________________________1.3530
CPU VCCIO Voltage__________________________1.13750
CPU System Agent Voltage___________________1.13750
CPU Graphics Voltage Mode__________________Offset Mode
Offset Mode Sign______________________________+
CPU Graphics Voltage Offset___________________0.315
PCH Core Voltage____________________________Auto
CPU Standby Voltage_________________________Auto

[tommiboi]

Hmm i wanted to buy these just for the RBG. Already have 3200Kit in my pc.

Anyways there is no performance boost between 3200 to 3866. So the 3600 is super good. Yes it frustrating that ram will not run at the speed you buy it for.

okay.
Did you try to dail in the setting manually ? If it wont boot up the volatge of you ram. it might just be that. The XMP setting is an OC anyways. So up the voltage to 1.375 or 1.4v

Could also be that your MOBO doesnt accept the speed.

[tommiboi]

Hmm i wanted to buy these just for the RBG. Already have 3200Kit in my pc.

Anyways there is no performance boost between 3200 to 3866. So the 3600 is super good. Yes it frustrating that ram will not run at the speed you buy it for.

okay.
Did you try to dail in the setting manually ? If it wont boot up the volatge of you ram. it might just be that. The XMP setting is an OC anyways. So up the voltage to 1.375 or 1.4v

Could also be that your MOBO doesnt accept the speed.

[samuel9521]

I tried with different voltages combinations, setting the DRAM Voltage to 1.5 and both VCCIO and VCCSA to 1.4, but nothing changed.

The fact is that the motherboard actually supports ram at 3866, and for now I haven't the gpu. The igpu shares system memory so I can see the difference in games between 3200MHz and 3600MHz.

On the mobo support page, it says that it accepts the 2x4GB non-RGB version of G.Skill Trident Z ram @3866. Maybe 16GB are too many for this moterboard, I don't think the RGB leds can make a difference.

P.S. I'm having some bsod playing Rocket League after about 30 min gaming, but the system passed stress tests and benchmarks like Cinebench R15, GeekBench and CPU-Z, so I've just increased the DRAM Voltage to 1.375 and both VCCIO and VCCSA to 1.15.

[JustinThyme]

disable the XMP and everything manually.

whats on your list above that just slaps the dog doo out of me

XMP DDR4-3866 18-19-19-39
DRAM Timings________________________________15-15-15-36

Its not at all uncommon for things not to play nice when doing an OC. keeping the 100 BCLCK is important and leaving XMP disabled is as well. you just have to find the sweet spot.
In the grand scheme of things higher clock rates do not always = better performance.
CL/freq x 1000 gives you the response time. Lower is bettter

CL 18/3866 =4.65ns
CL 15/3600=4.16ns which is actually faster
CL15/3400=4.41ns which is still faster
CL15/3200=4.68ns which is virtually the same as the 3866 at CL18

[samuel9521]

JustinThyme wrote:

whats on your list above that just slaps the dog doo out of me

XMP DDR4-3866 18-19-19-39
DRAM Timings________________________________15-15-15-36

Well I lowered the timings for an higher bandwidth, and my ram can run with those ones at a relatively low voltage, but the XMP profile uses different timings and frequency.

So the only thing you're suggesting me to do is disabling the XMP, leaving frequency at 3600 and timings at 15-15-15-36?

[tommiboi]

are you saying you use the IGPU ? and not an external GPU ?

[samuel9521]

tommiboi wrote:
are you saying you use the IGPU ? and not an external GPU ?

Yes but it's only a temporary solution, i'm going to buy a real gpu soon 😛

[Korth]

tommiboi wrote:
are you saying you use the IGPU ? and not an external GPU ?

samuel9521 wrote:
The fact is that the motherboard actually supports ram at 3866, and for now I haven't the gpu. The igpu shares system memory so I can see the difference in games between 3200MHz and 3600MHz.

On the mobo support page, it says that it accepts the 2x4GB non-RGB version of G.Skill Trident Z ram @3866. Maybe 16GB are too many for this moterboard, I don't think the RGB leds can make a difference.

He's using processor iGPU (which shares main memory), not PCIe GPU (with onboard VRAM). So faster memory = faster graphics.

F4-3866C18D-16GTZR is single-sided single-rank Samsung (20nm) 8Gb B-die K4A8G085WB-BCPB. Nice kit.

STRIX Z270F specifications do list "support" for up to DDR4-3866(O.C.)
I couldn't find a DDR4 QVL for this mobo, F4-3866C18D-16GTZR may or may not technically qualify as "compatible" memory.

Of course anything faster than the JEDEC-2400 natively supported in a KBL CPU is an overclock and has *absolutely no guarantee* of working at (faster) non-JEDEC speeds. But it's not too hard to run it faster (even a lot faster) on a decent mobo like this one, especially with some extra voltage.
Yet DDR4-3866 is the top extreme ASUS advertises on the STRIX Z270F (it probably failed with the DDR4-4000, -4133, and even -4266 memories they tested successfully on MAXIMUS IX mobos). I suspect ASUS might have used low-density (2x2GB or 2x4GB) DIMMs or even a single DIMM when performing these tests - and it's obvious they used an "above average" CPU with strong iMCs - they may have even used exotic cooling. But I don't know the specifics. ASUS might volunteer more accurate information.

The main hardware factor limiting your DDR4 XMP/overclock is usually your particular CPU part, not your particular motherboard part.

iGPU uses power and produces heat, so using it will limit the budgets flowing through the rest of the silicon die. I think you'll be able to run your RAM faster (though perhaps still not at full DDR4-3866) when using PCIe GPU instead of iGPU.