Bus Speed Fluctuating? Normal or Not?

[maxbrokeaway]

Ok here's the situation. I'm running an Asus z97-AR MoBo, with a 4790K, as well as 16GB of G-skill Sniper 1866Mhz @ CAS 9.

Only modifications I've made in bios was enabling XMP, and I turned off CPU Spread Spectrum, as well as set custom fan curves.


While gaming, I use the windows power options set to "High Performance" that runs my CPU at 4400Mhz.



Here's the issue, I've noticed recently (Meaning I don't know if it's always been this way) in HWMonitor that occasionally my Core Speed will go to 4511Mhz, or sometimes the other way to 4295Mhz, while gaming. Doing a little digging I found out it was due to the bus speed fluctuating every so often. It normally sits at 99.98Mhz. It's normally very stable and sits right on that speed. I check HWMonitor often while I game and it's only once or twice in an hour or so that I'll see it had at some point fluctuated.

I was able to duplicate the issue of the Bus Speed going to 102 by using Passmark Performance Test. I saw that it would start intermittently bouncing from 99.98 to 102 whenever it was doing Memory and SSD related testing.



I have attempted to fix the issue by turning off the XMP profile and going back to default BIOS settings. Tried Turning off C-States, Tried turning off EIST. To no avail. All of these things yield the exact same behavior from the Bus Speed.


I've ran stability tests for hours using AIDA64 with no issue, Package temp hovering around 56C, while individual cores top out in the low 70s. I've also ran Memtest for several hours and the RAM had 0 errors.


So my question is, am I just trying to fix a non-issue? Is this perfectly normal?


If it's due to something hardware related, the only thing I can think of that would have caused it was I had some RAM die on me after I air dusted the inside of my case a few months ago. The computer powered on and off and on about 3 times quickly and then gave me the red led RAM PROBLEM indicator. Swapped out the ram with an 8GB kit and all was well, used that for a couple months before upgrading to the 16GB kit. The Bus Speed fluctuation was happening with both kits so I have ruled out that it could be due to specific RAM.

Anyway, Thank you so much for taking the time to read the post and hopefully I hear back from some of you soon.

Thanks,

 

[syked3]

It is normal for bus speed to fluctuate by a few MHz, it wont affect function or performance. The only time when you should be worried about bus speeds is if they start fluctuating by really large amounts, that can cause system instability

 

[maxbrokeaway]

It is normal for bus speed to fluctuate by a few MHz, it wont affect function or performance. The only time when you should be worried about bus speeds is if they start fluctuating by really large amounts, that can cause system instability

so the fact that it's fluctuating and causing my CPU clock to go +/- 100Mhz is a non-issue? And what would you define as a "large amount"? So that I can know for the future.

 

[syked3]

That shouldn't be an issue. What is an issue is if your cpu clock starts going from 3GHz to 1Ghz etc