Some effects of Ram frequency on Coffee Lake CPUs I discovered

[Bhav]

So previously I was trying to get my cheapo crucial ballistix ram stable at higher clocks at CL14. 2800 Mhz was a complete no go, and after trying for several days, 2700 was still slightly unstable leading to crashes after prolonged use, and using 1.4v on the CPU and 1.425v on the Ram still didnt bring stability, and my windows install ended up corrupting again.

 

So after reinstalling, I dropped it back down to 2666 Mhz CL14, 1.4v ram, 1.38v CPU. I also ran these same voltages for most of the time I was trying to get 2700 Mhz stable.

 

I ended up discovering that at the stock frequency of 2666 Mhz and with the same tighter timings at 1.4v (14-16-30-1T), and CPU settings of 5 Ghz @ 1.38v, my max CPU temps dropped from max 88c all the way to max 70c with the same ambient temps and in the same game Im currently playing (Sim City).

 

Whether the reason for having difficulty going above 2666 CL14 was due to the cheap ram, or due to the IMC on my CPU, running the ram just 34 MHZ higher was causing my CPU to get stressed significantly a lot more. So it looks like Im stuck to the stock frequency of 2666 Mhz for CL14, which is fine for how much less I paid for this ram, and how nicely the sticks also match my build.

 

Whether or not I will eventually sell this ram and upgrade to samsung b die or any better in the future if prices come down Im unsure of now, I dont even think ram willl get any cheaper for a long time to allow that.

[maartendc]

1 hour ago, Bhav said:

So previously I was trying to get my cheapo crucial ballistix ram stable at higher clocks at CL14. 2800 Mhz was a complete no go, and after trying for several days, 2700 was still slightly unstable leading to crashes after prolonged use, and using 1.4v on the CPU and 1.425v on the Ram still didnt bring stability, and my windows install ended up corrupting again.

 

So after reinstalling, I dropped it back down to 2666 Mhz CL14, 1.4v ram, 1.38v CPU. I also ran these same voltages for most of the time I was trying to get 2700 Mhz stable.

 

I ended up discovering that at the stock frequency of 2666 Mhz and with the same tighter timings at 1.4v (14-16-30-1T), and CPU settings of 5 Ghz @ 1.38v, my max CPU temps dropped from max 88c all the way to max 70c with the same ambient temps and in the same game Im currently playing (Sim City).

 

Whether the reason for having difficulty going above 2666 CL14 was due to the cheap ram, or due to the IMC on my CPU, running the ram just 34 MHZ higher was causing my CPU to get stressed significantly a lot more. So it looks like Im stuck to the stock frequency of 2666 Mhz for CL14, which is fine for how much less I paid for this ram, and how nicely the sticks also match my build.

 

Whether or not I will eventually sell this ram and upgrade to samsung b die or any better in the future if prices come down Im unsure of now, I dont even think ram willl get any cheaper for a long time to allow that.

Well are you surprised you are getting a warmer CPU? Running more voltage through it will make it run warmer.

 

I doubt you would be able to tell any difference in performance between 2666 and 2700 or even 3000. It is only when you start comparing 2166 to 3200 for example that you notice any meaningful difference.

[Bhav]

4 minutes ago, maartendc said:

Well are you surprised you are getting a warmer CPU? Running more voltage through it will make it run warmer.

 

I doubt you would be able to tell any difference in performance between 2666 and 2700 or even 3000. It is only when you start comparing 2166 to 3200 for example that you notice any meaningful difference.

The voltages were the same in both cases. And also NVM this whole thread, the CPU warmed up to the same max after being on all day.

[maartendc]

1 hour ago, Bhav said:

... 2700 was still slightly unstable leading to crashes after prolonged use, and using 1.4v on the CPU ...

 

I dropped it back down to 2666 Mhz CL14, 1.4v ram, 1.38v CPU....

Sorry, I thought I read that you dropped the CPU from 1.4V to 1.38V

[Ebony Falcon]

Memory controller is inchip so adding voltage to ram will make it run hotter 

[danrey84]

As the person above said the memory controller is on the chip now so the more heat you pump into the CPU and RAM the more heat you get. Plus the higher the RAM speed can sometimes lead to unstable clocks on the cpu.