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Impossible to reach 1866 MHz with 1600 MHz RAM on Z97-A USB3.1

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New Member
Sep 2, 2010
Since a couple of weeks ago my mind was invaded to OC my RAM (DDR3 Crucial Ballistix Sport 4X8GB) since I saw a post here on OCN from a dude OCing the very same model up to 2400 CL13. So, after a ton of reading I decided to give it a try baby-steps approach, so I went with 1866 CL10 (10-10-10-30 @1.54v) I passed an hour of google's stressapptest but then I got some BSOD playing videos, so I went back to stock (1600 9-9-9-24) and read some more.
I give it another shot with the same values, but this time it didn't pass even stressapptest, so I went to the BIOS and give it to the System Agent +100mv (Leaving it at 1.1v), the OC was, again 1866 CL10, this time it passed 90 minutes of stressapp test, but then again, I had random BSODs playing videos and I got a BSOD regarding eamonm.sys (I suspect it's ESET Smart Sec. service) with the legend "system_service_exception". After that I removed the OC completely and never tried it again.
Some people says to rise the VCCIO (Analog and Digital) to 1.1 to give some stability, others says that giving voltage to the SA is more than enough, the thing is that my MOBO doesn't show values for the VCCIO (nor digital, nor analog) so I don't want to take the risk rising the voltage when I'm completely blindfolded.

I know that this is a lottery, but I refuse to think that I got such a bad luck that a 1600MHz RAM from a renowned brand can't do even 1866. The mobo is supossedly be more than enough, so, what am I doing wrong? (Screenshots of the final stressapp test I passed and the stock BIOS values below)

Sys specs:

4690K @stock
Z97-A USB 3.1
Sapphire RX480
Crucial Ballistix Sport DDR3 1600 CL9 1.5v
Seasonic Platinum 1kW



  • 1866.PNG
    710 KB · Views: 36


Senior Pink Member
Sep 13, 2015
I would start by putting everything including timings back to auto.


up your dram to 1.65v
Then add .1v to system agent, analog IO and Digital IO.

Then load into your system at 1600mhz with timings on auto.

If it boots ok go back and up your speed to 1866. If it boots again and is stable continue going up leaving timings on auto until you no longer have stability.

If that is successful you can then start working your timings down from there.

Your system is going to take a little finesse to get right running 32gb total across 4 sticks. This is putting extra stress on the memory controller and will probably take more voltage than normal to help compensate for this.