Do memory (Ram) timings effect cpu temperatures?

nic8good

Commendable
Mar 11, 2018
7
0
1,510
Hello all,

I have recently realised that activating the xmp memory profile causes my cpu temps to increase. I have been told by intel that this is likely because the memory is running at a higher MHZ than the cpu was built to support (my ram is 3000mhz and my 7700k is designed to support up to 2400mhz) so the cpu memory controller is having to work harder to keep up (which then increases temps).

I mostly use my pc for gaming (no rendering or live streaming) so i don't really care if i have to lower the ram to 2400mhz, however i was hoping that i could lower the mhz to 2400 and then tighten the timings (CAS, tRCD, tRP, tRAS latencies), so the performance is basically the same.

So my questions are: Will lowering the timings also put strain on the CPU memory controller? and Will lowering the timings cause the cpu temperature to increase?

My current setup is 2x8GB 3000mhz 15,17,17,35 @1.35v (XMP defaults) but i'm looking to change it to 2400mhz 12,14,14,29 @1.2v (voltage may need to be higher but i'll test that). According to this link the performance should be similar: https://i.imgur.com/MhqKfkf_d.webp?maxwidth=640&shape=thumb&fidelity=high

Thanks.
 
Solution
There are many factors that affect CPU overclocking to the maximum stable operating zone that are memory related. One of the most common is just occupying the 2 main primary recommended memory slots for maximum overclock and not occupying all 4 memory slots on dual channel motherboards so equipped, most motherboard manuals even reference this. Overclocking stability also is affected if the motherboard is running cooler and the DDR4 slot voltage is running at 1.20v specification, can it be run higher of course it can to support higher memory speeds, but then comes the additional heat.

Keep in mind if you're not overclocking the CPU multiplier at all the memory speed you run is really acceptable, but the higher you push the CPU...
Timings won't affect the CPU at all no
Its the jump in memory controller clock speed & the increased ram voltage that hikes the cpu temp - although Ive honestly never seen it raise enough to cause massive concern .
How much are we talking ? 4-5c is normally the max.
 


Thanks for the reply and the confirmation. Right now i'm trying to lower the temps for my 7700k as far as possible, I've already lowered the vcore below stock (from 1.2v to 1.175v ) at a slight OC of 4.6ghz. I'm now looking at how the ram might affect the cpu temp. Like you say it is only up to 4-6C higher at XMP settings but i'm trying to get the temps as low as possible (summer is coming). Plus if i can get the same performance at 5c lower (by changing timings and lowering mhz) then that would be perfect.

BTW Its a real shame that Intel was so cheap with their TIM, my chip can get to 5ghz stable at 1.35 vcore (maybe 5.1/5.2 at 1.4) but the temps hit 98C in aida64 and 100c in intelburntest, I want to run at 80c max without deliding (I like my warranty). Anyway, I'm currently running hci memtest and the 2400mhz-12,14,14,29 settings look stable so far (at 600% right now) so all seems good. I just wish i'd known that the ram OC would effect the cpu temps when i bought the ram, I would have just got the 2400mhz version and lowered the timings.

Two more questions: Are the possible timings only dependent on the rams ability/do other components limit the degree to which you can lower the timings? and Can the motherboard/CPU restrict the ability for the ram to function at lower timings? I ask because on the Asus website none of the supported ram is running at timings as low as mine (I've got the asus z170-k board). I hope that makes sense...

Thanks again for the reply
 
There are many factors that affect CPU overclocking to the maximum stable operating zone that are memory related. One of the most common is just occupying the 2 main primary recommended memory slots for maximum overclock and not occupying all 4 memory slots on dual channel motherboards so equipped, most motherboard manuals even reference this. Overclocking stability also is affected if the motherboard is running cooler and the DDR4 slot voltage is running at 1.20v specification, can it be run higher of course it can to support higher memory speeds, but then comes the additional heat.

Keep in mind if you're not overclocking the CPU multiplier at all the memory speed you run is really acceptable, but the higher you push the CPU multiplier the more negativity you get heat wise because the more voltage is required to reach stability.

http://www.tomshardware.com/forum/id-2345618/reaching-cpu-overclocking-stability.html

Memory speed however will definitely affect CPU overall temperature, I have personally tested that myself and also a few other well known here at Toms Hardware have tested it as well.

http://www.tomshardware.com/forum/i...r-effect-raised-multiplier-cpu-overclock.html

I see one of your concerns is lowering memory speed and it's affect on performance being able to be countered by lower DDR4 slot voltage and running tighter timings and that's possible with some of the memory modules, but you may not see a performance equality doing that but you will see lower CPU temperatures.

Taking manual control over the memory settings vs XMP profile will allow you to get away from some of the motherboard automatic setting that allow XMP to run stable in the first place that in some motherboards run aggressively higher supporting voltages than needed.

You have to decide for yourself what's most important to you a faster performing machine all the time or just when it's needed for benchmarks and such as that, that's what setting overclocking memory profiles are great for because you don't need the pedal to the metal for normal everyday use, but you do need the lowest operational temperatures you can run for CPU longevity.

Helping you would be easier if you listed your memory specs, brand, model #, amount, etc., of exactly what you are running, and other specs besides the motherboard as well even including the operating system you're running?

Also how are you cooling the CPU?
 
Solution


No and No



Yes and Yes



 


Thanks for the answers and the other detailed reply, i had actually read your post (one of the links you provided) but i couldn't see any info on ram timings (very useful for temp information though). In your reply you mentioned that i may not be able to achieve a performance equality with lower timings at 2400mhz compared with xmp settings, while i don't mind a small performance loss, I was hoping the speed would be roughly the same (https://i.imgur.com/MhqKfkf_d.webp?maxwidth=640&shape=thumb&fidelity=high). I'm not sure how accurate that chart is but i was hoping it was correct (it appears to be, IF my math is correct....).

You also asked about my PC specs, they are as follows-

  • -7700k 4.6ghz oc at 1.175v (I'll try for 4.8 at good temps now that the ram is lower than xmp settings)
    -corsair vengeance lpx 2x8gb ddr4 3000mhz (manufacture code CMK16GX4M1B3000C15)
    -asus z170-k motherboard (latest bios)
    -Nvidia GTX 1070 evga ftw
    -rmx 650 corsair psu
    -corsair h100i v2 water cooler (CPU cooler)
    -2x512gb samsung 850 evo ssd's
    -2x corsair ml140 pro fans
    -running on the latest windows 10 version
I have just managed to get the ram to function at 2400mhz with 12,14,14,29 timings at 1.2v (tested with HCI memtest to 1000% on 95% of ram). Which has resulted in a 3c reduction in max temps (and the average is about 5c lower) when running HCI memtest compared with xmp settings (which makes sense based on the info you have given).

One thing that does bother me though is that the supported ram for the z170k does not have timings that are as low as mine are currently set to (see https://www.asus.com/uk/Motherboards/Z170-K/HelpDesk_QVL/). I'm guessing its because most ram doesn't come with/is sold with such low timings but I don't want to damage my motherboard by running the timings so low (I intend to keep the system going as long as possible while only upgrading my gpu and possibly ram).

Thanks again.
 
I have just managed to get the ram to function at 2400mhz with 12,14,14,29 timings at 1.2v

That's great! :)

One thing that does bother me though is that the supported ram for the z170k does not have timings that are as low as mine are currently set to (see https://www.asus.com/uk/Motherboards/Z170-K/HelpDesk_QV...). I'm guessing its because most ram doesn't come with/is sold with such low timings but I don't want to damage my motherboard by running the timings so low (I intend to keep the system going as long as possible while only upgrading my gpu and possibly ram).

Don't give that another thought regarding hurting anything, you're fine!
Memory tested in motherboards by manufacturers are not overclock or underclock tested just stock settings.
 


Thanks for all your help, I can rest easy now knowing everything is stable and safe. BTW i could probably push the ram further but i'm happy that i managed to get the CAS value to 12 (I doubt i would notice any real performance improvement if i pushed it further, plus HCI memtest takes a while to get to 1000%).

Take care and all the best.

P.S.(For anyone reading this thread in the future)- I have selected Ryan's first answer as the solution as it is the most detailed and informative, however all the posts are useful and relevant if you're concerned about timings and temps.