RAM Operating voltage exceeds recommended of 1.5v

[Jonny on Torry]

Im aware that there are many questions similar to the one I'm asking. Much of them look like this:

The G.Skill Ripjaws X Series 16GB (2 x 8GB) DDR3-2400 Memory operating voltage of 1.65V exceeds the Intel Haswell Refresh CPU recommended maximum of 1.5V+5% (1.575V). This memory module may run at a reduced clock rate to meet the 1.5V voltage recommendation, or may require running at a voltage greater than the Intel recommended maximum.

Given that people are commonly asking what this means and if their parts are compatible, my questions are somewhat different.

1.) Is there anything I need to do to make it run at a reduced clock rate to meet the 1.5v? Whether that be editing BIOS or any settings, or would the board do this automatically?

2.) What is affected when running the sticks at 1.5v compared to 1.65v?

3.) Out of curiosity, is it the CPU that determines the operating voltage?

I know that the board, sticks, and CPU are compatible with one another as I've seen them used in many other builds. My goal is to avoid overclocking/running them past their recommended voltage, whilst still getting the most out of these sticks. Below is my potential build, and many thanks in advance!


ASRock Z97 EXTREME9 ATX LGA1150 Motherboard
Intel Core i7-4790K 4.0GHz Quad-Core Processor
Corsair H100i 77.0 CFM Liquid CPU Cooler
G.Skill Ripjaws X Series 16GB (2 x 8GB) DDR3-2400 Memory
Gigabyte GeForce GTX 970 4GB WINDFORCE Video Card (2-Way SLI)
Crucial MX100 512GB 2.5" Solid State Drive
Seagate Barracuda 3TB 3.5" 7200RPM Internal Hard Drive (x4)
Corsair 760W 80+ Platinum Certified Fully-Modular ATX Power Supply
Cooler Master HAF X ATX Full Tower Case

 

[Eximo]

In this particular case, and likely all future Intel chips, the memory controller is inside the CPU. So you risk damaging the CPU directly by running the high voltage.

DDR3-2400 is a fairly high clock to reach. When you drop it in it will likely run at 1333 anyway, and you would need to use an XMP profile or set it manually to get those speeds. That memory might have several profiles, including one that operates at 1.5 volts.

I would just look for DDR3-1866 with a CAS of 9 or DDR3-2133 with a CAS of 10 that is 1.5 volt.

I see lots of people running 1.65volt memory, but they probably upgrade often and don't see the downsides. Only been about 18 months since the chips have been out as well. (Tom's reviewers did burn out a CPU though)

 

[TweeDoor]

I made the misstake of buying 1.65v ram... Im re-adjusting them to run at 1.55v as thats perfictly fine, and there just as fast once you tweak them well. Dont give up on high voltage ram(at least its rated to handle the voltage), just needs adjusting.

 

[LucoTF]

Typically the JDEC table will mean that it runs at a reduced speed and 1.5v anyway, so it doesn't matter

 

[Eximo]

Typically the JDEC table will mean that it runs at a reduced speed and 1.5v anyway, so it doesn't matter

On a slightly related topic. How is your 1st Gen i7 memory holding up?

My own I7-950 and its Corsair Dominator 1600 is starting to fail to recognize all of the memory. And I ran into another person with the exact same problem. At the time all of the 'fast' memory was 1.65 volt, but the controller was designed to handle that, but now I'm not so sure.

Just gathering a little more data.

 

[LucoTF]

The memory is newer than the cpu...