OC stable on P95 but crashes in games?

[Zberg]

Hey community, question for you guys I am a little confused on.  I have been having issues with a finicky OC recently.  I thought it was stable, but it seems that may not be the case.  I took my 2080's out of SLI to take that variable out of the equation.  Also took that single 2080 to stock settings as well.

 

9900k - was stable at 5.1 GHz in testing, but was getting random crashes in games.  Usually CPU was fluctuating between 20-50% utilization, games GPU bound 100%.  Random things will crash games sometimes in menus, sometimes when picking up an item, sometimes looking around.  It isn't so frequent that I can't play (in fact, some sessions it won't happen at all), and often I will get in 1-2 hours before it happens.  But it obviously takes you out of the game for a couple minutes until reboot.   I decided to just take the OC back off to stock and see what happens...and now it NEVER crashes.  Not one single time since reverting to stock.  

 

I then tried fooling around with the Vcore, LLC, and clocks to see if I can do something to make it stable in games.  Nothing has worked like taking it back to stock.

 

My big question, is how the hell can it pass AIDA64 for 45 min-1 hour, and prime 95, and then crash in games when it is NEVER, EVER at 100% utilization for any significant amount of time on multiple cores.  I have HW monitor up when gaming and it's never like I am getting high temps (50's-70s gaming), or high utilization for that matter...but it still has occasional crashes.  Then I take off the OC, crashes gone.  I have tried 5.1 GHz, 5.0GHz (both of these pass P95 and AIDA64, with the 5.1 getting into the 90's in P95 though).  LLC tried at pretty much all of the highest 3 levels (turbo, extreme, extreme+).  Additionally, crashes only ever happen in games, nothing else I do (internet, streaming, light photo/video editing stuff, all simultaneously) crashes it.  

 

So is there some trick and/or setting of the many settings on the BIOS that might remedy this?  Anyone heard of a similar situation? My obvious thought, as I am lowering the OC to 4.9, then 4.8 is at that point just take the whole thing off since at stock it's putting everything at 4.7 for all 8 core load anyways.  I mean it's never close to CPU bottlenecked so I don't NEED it, but my concern is that in the future if it would benefit me I can't seem to get it just right.  

 

Drop some knowledge bombs on me?

 

 

[Jurrunio]

also possible that the voltage spike caused by going load to idle and back to load again to cause the crashes. You can increase the VRM mosfet switching frequency to help with that, though VRM thermal output will then shoot up so make sure you only do this on a good board.

[Enderman]

It's definitely possible for some tasks to be stable and other tasks (which you would think are a lighter load) to not be.

So that means your CPU is unstable.

[Zberg]

16 minutes ago, Jurrunio said:

also possible that the voltage spike caused by going load to idle and back to load again to cause the crashes. You can increase the VRM mosfet switching frequency to help with that, though VRM thermal output will then shoot up so make sure you only do this on a good board.

aha, I shall give that a go!

[GMart84]

@Zberg What OC settings are you using?

[Zberg]

21 minutes ago, GMart84 said:

@Zberg What OC settings are you using?

The setting that seems to give me the fewest crashes (again this is like a random crash after 1-2 hours of gaming, though still very annoying to me) is a 5.0 GHz OC.

 

I have an Aorus Master MB.  When I decided to mess with the OC to remedy things, I first just went back, reset to stock, and followed right along with their OC guide for a fresh restart if you will.  So 5.0GHz, 1.35V, turbo LLC, XMP enabled, all of the "C states" disabled, turned off "enhanced multi-core performance".  To that I then added an AVX offset of 2 and put LLC to extreme.  That combination seems to have the least frequent crashes.  Thermals are still fine in stability testing on it.  I have gotten away with lower Vcore in the past, but was hoping this higher number would help me in case it was power hungry (and also it was what the gigabyte OC guide for the board said to start at).  Crashing less, but still not perfect clearly  

[GMart84]

@Zberg Below are the settings I am using on 9900K, obviously you know that there are chip differences but this is what I have.  I am using an Aorus Z390 Extreme

 

CPU Ratio 51x

BCLK 100.00

Uncore Ratio 48x

CPU LLC Turbo (for Higher OCs I have to bring it up to Extreme)

CPU Vcore 1.29 (Reading in Windows is showing 1.296 and sometimes spikes to 1.308)

VCCIO 1.050

VCCSA 1.100

XMP Enabled - Timings Adjusted down to 15-16-16-36

DRAM Voltage 1.375

 

I have noticed that when I leave the VCCIO and VCCSA on Auto they seem to stay at like 0.950 and 1.050 respectively and that made my OC less stable.

 

Also when I mess with the BCLK it seems to really effect performance in general with things outside of the CPU, as it should.

[Zberg]

29 minutes ago, GMart84 said:

@Zberg Below are the settings I am using on 9900K, obviously you know that there are chip differences but this is what I have.  I am using an Aorus Z390 Extreme

 

CPU Ratio 51x

BCLK 100.00

Uncore Ratio 48x

CPU LLC Turbo (for Higher OCs I have to bring it up to Extreme)

CPU Vcore 1.29 (Reading in Windows is showing 1.296 and sometimes spikes to 1.308)

VCCIO 1.050

VCCSA 1.100

XMP Enabled - Timings Adjusted down to 15-16-16-36

DRAM Voltage 1.375

 

I have noticed that when I leave the VCCIO and VCCSA on Auto they seem to stay at like 0.950 and 1.050 respectively and that made my OC less stable.

 

Also when I mess with the BCLK it seems to really effect performance in general with things outside of the CPU, as it should.

I appreciate the info very much, I have not altered the VCCIO or VCCSA myself in the past, maybe that could help as well.  I am trying out what the above guys were saying with the switching freq increased to see what that does, just did a little round of an hour gaming and so far no crash.  Fingers crosses.  Thanks again

[GMart84]

@Zberg The link below is to a reasonable OC guide that talks through the different settings and what they do.  Best of luck.

 

https://www.tweaktown.com/guides/8812/gigabyte-z390-9th-gen-oc-guide-vrm-thermal-test/index.html