Overclocking Z370 DDR4 memory uncanny problem

[wingman99]

After overclocking Gigabyte Z370 G.SKILL Ripjaws v 16GB F4-3200C14D-16GVK to 3600 15-15-15-35 Vccio 1.15v, Vccsa 1.27v DDR 1.45v for two days of testing with 6 instances of HCI MemTest and not changing my memory overclock settings it has come down to a weird problem with rebooting my Gigabyte z370. Some boots HCI MemTest runs fine without error for 100-400%. Then sometimes after testing from ~1-20 boots I have all kinds of errors with HCI MemTest preliminary test or at 1%-30% in the testing. I tried G.SKILL TridentZ RGB F4-4000C17D-16GTZR at 3600 15-15-15-35 with the same results. What is the opinion to have a failed test only when rebooting the PC ~1-20 times?

 

[Alaric]

Is your memory Boot Mode in the BIOS set to Enable Fast Boot? I'd look here for potential issues first:

>> Memory Boot Mode (Note)
Provides memory detection and training methods.
>>Auto Lets the BIOS automatically configure this setting. (Default)
Enable Fast Boot Skip memory detection and training in some specific criteria for faster memory
boot.
>>Disable Fast Boot Detect and train memory at every single boot.
>> Memory Enhancement Settings
Provides three different memory performance enhancement settings: Normal (basic performance), Enhanced
Stability, and Enhanced Performance. (Default: Normal)

 

[wingman99]

Tried disable fast boot and it took a long time to boot so I went back to AUTO, so when I make memory speed and timing change I don't have to clear CMOS if it fails to boot.

Realtime Memory timing Allows you to fine-tune memory timings after the BIOS stage. Disabled that and will have to test later.

 

[Woomack]

It looks like stability issue which happens when timings are too tight / there is some interference ( PCB etc issues ). I would check it at more relaxed timings like 16-16-16 or 17-17-17 as everything else seems fine for these settings.
I bet you won't have these problems when you power down the PSU.

 

[wingman99]

Well I already tried more relaxed timings and lowering the speed to 3466 and PSU powering down was the same. Tried a new Gigabyte motherboard with exactly the same reboot only failure in testing. Trying the only option that I have not tried Memory Enhancement Settings relax OC.

It is very odd I can test forever with 6 instances of HCI MemTest 100-400% testing over and over. However, when I reboot ~1-20 times testing each time with HCI MemTest up to 30%, it will fail on one boot always 1-30% testing over and over.

 

[wingman99]

Well it is not performance beneficial to run Memory Enhancement Settings with enhanced stability.

3200 14-14-14-34 Memory Enhancement Setting default normal.


3600 15-15-15-35 Memory Enhancement Setting enhanced stability.


3600 15-15-15-35 Memory Enhancement Setting default normal.

 

[Alaric]

Mine wouldn't get stable until I set it to Enhanced Performance.

 

[Woomack]

Maxxmem is not so good to check performance. You can have 4-5GB/s difference between runs... just repeat test couple of times and you will see.
Maybe check "winsat mem" command in Windows. It usually shows performance better as it shows how Windows operates on available memory.

Somehow I doubt that enchanced stability/performance changes anything else than memory settings which are hidden or under auto settings. Usually it's like stable mode is at more relaxed settings and the one which improves performance is on tighter sub timings or has something else enabled/disabled. At least it was working this way on earlier Gigabyte boards but I was always using manual settings as some timings were just wrong.

 

[Alaric]

I set my timings manually and tried Enhanced Stability, and it crashed if I touched the settings, or refused to boot. On Enhanced Performance it was much better. I don't remember if I even looked at sub timings, though. It was early in my RAM OCing, so I just left on the performance setting and went from there. That worked better than Normal, too.

 

[wingman99]

winsat mem
32299.59 MB/s 3200 14-14-14-34 normal
27959.97 MB/s 3600 15-15-15-35 enhanced stability.
36418.47 MB/s 3600 15-15-15-35 normal
36461.74 MB/s 3600 15-15-15-35 enhanced performance
Do you know what the secondary timings should be?

 

[Alaric]

Post #76 here http://www.overclockers.com/forums/showthread.php/787371-3866-MHz-Too-much-is-enough/page4 has my settings, with three exceptions: My uncore is now at 4400 MHz, My CPU is at 4700 MHz, and my tRFC is now at 530. My mobo has point to measure actual voltage, so I put the actual measurements up. The 1.450 vDIMM is set to 1.460 in the BIOS. The tREFI is set manually according to JEDEC standard for that speed. Going higher can make a difference, but it's a narrow window. If it will take 20,000 it's worth a shot. The formula is RAM speed (actual) X 7.8=tREFI (3733=1866 X 7.8= 14,559).

Edit: What is your command rate set to? Mine is 2T. Also, having background processes running lowers your winsat mem score. Especially browsers that are resource hogs. Probably because it checks available memory.

 

[Woomack]

Easy way to set tight sub timings ( secondary at least ) ... run memory at auto/SPD ... save timings ... set higher frequency with the same sub timings as at auto/SPD. Works in most cases on Samsung B up to at least 3600. There are some single timings that sometimes have to be corrected.
Max values are limited by timing tables. Some timings have rules like can't be higher than xxx or can't be lower than some value. Sometimes motherboards are adjusting whatever you set wrong like with tWCL.

 

[wingman99]

What do you think about ASUS motherboard memory overclocking?

 

[Woomack]

If you want something good for OC then get ASUS ROG ( not Strix ), ASRock ( pretty much any Taichi or higher series ) or any MSI Carbon or similar with printed DDR4 boost on the PCB.
One of the easiest boards for memory OC is MSI Z370 Gaming ITX and it's also cheaper than most competition but it's ITX board. 2 slot boards OC better because of shorter traces and lower interference.
I have Trident Z 4266 RGB kit and it runs at XMP 4266 19-19-19 stable. Actually I had no time for more tests so when I got it, it was installed on mentioned MSI board and was working 24/7 for about a month. Today I took whole rig to work and now it runs in AIDA64 stability test. It's just because I've replaced my gaming PC with TR and wanted to use Z370 for memory tests. At least 2 short forum reviews should appear on the OCF in next days. One is Trident Z 4266 and other one is Team Xtreem 4133 CL18. I'm just not sure when as recently I have limited time.

 

[wingman99]

Do you think I will get stable memory overclocking at 3600-3733 speed with ASUS TUF Z370-PLUS GAMING. I think there is just something unreliable with the BIOS when rebooting this Gigabyte model that Alaric does not have. If there is no testing errors and I don't reboot the Gigabyte works fine forever.

 

[Woomack]

It's one of the reasons why I don't like Gigabyte for tests/competitive benching ... these many small issues that you find after some time and support won't ever fix. Their older boards were solid but for last ~2-3 years they release too many mobos and don't care to prepare them right. That's just my experience while I still sell some Gigabyte at work. It's just that what matters for me is not important for most users.

I have no idea what about ASUS TUF. I see it's in promo price so I guess you wish something in similar price. Do you have any budget or something ? I won't hide that I was testing only couple of Z370 motherboards as I didn't even want to buy anything for this chipset. I got something for review and I decided to buy MSI ITX for memory tests but I wasn't really testing anything from ASUS on Z370 chipset.

I guess that ASRock will work fine but again I had no chance to test their full ATX Z370 motherboards to tell how they work. Recently I was testing multiple X299/X399 ASRock motherboards and all were stable in quad channel at 3600-4000 (depends on used memory kit).

 

[wingman99]

ASUS TUF Z370-PLUS GAMINGI like the ASUS crashfree bios 3 and USD 124.99 + no tax at the newegg. Are ASUS motherboards not stable, I see a lot of BIOS updates for Improve system stability?

 

[wingman99]

Well I was using the ASUS TUF Z370 Plus Gaming Motherboard with the same components and it was memory overclocked to 3866 16-16-16-36 passed memtest86 and HCI MemTest also stable for 3 weeks all the time every boot. The processor did not overclock as good as my Gigabyte Z370. I was going to keep the ASUS TUF Z370 Plus Gaming. However, when I flashed the BIOS update last night it did not reboot up, so much for crash free BIOS 3. So I'm back to my Gigabyte Z370.