What is the effect of running memory at a LOWER voltage?

[pharrg]

What is the effect of running memory at a lower voltage? The best memory I find of the type my board needs is rated 1.65v, but my board recomments 1.5v memory. If I use memory rated higher will it cause problems? Will it affect performance? I guess I don't understand whether the voltage rating on memory modules is the maximum that it's rated to run at? or is that the minimum it needs? Thanks!

 

[darkguset]

The higher voltage usually allows memory modules (as well as lots of electronics) to run at higher speeds or tighter timings, that is because of the transistor nature inside, it is a bit complicated, but that is how it is for now. Of course more voltage produces more heat too and reduces the life span of the electronics involved due to electromigration and other several factors. Hence there is a point where higher voltage will bring more heat in and produce less benefits like higher speed, up to the point where the transistors or the silicon will be damaged (irreversably). That is why it is not suggested to put a lot more voltage on sticks, but ususally remain within 5% of their rated value from the memory manufacturer and not the motherboard manufacturer irrelevant of their suggestions. If the memory is rated at 1.65V from the memory manufacturer then that is what you should do. If the memory fails or not works, the mainboard manufacturer will have nothing to do with it, you will have to deal with the memory manufacturer. Hence try to stay within THEIR specifications.
If you use lower voltages for your memory:
1) You will produce less heat and consume less power BUT
2) The memory might not work correctly, produce errors, or not work at all. If it works, it will probably not work at the rated timings and work at lower timings. If you are not into every juice of performance your system can give you, then you might not really care, but if you are you will want to increase the voltage a bit to achieve those rated timings.
The voltage rated on the memory sticks is a medium value: it is a recommended value. If you go below, they might not work, if you go much higher you are risking of voiding your warranty and destroying the sticks.

I hope i was clear.

 

[pharrg]

Thanks! I really appreciate all that info. That helps a lot. So, it sounds like if I get the 1.65v memory, I can go into the bios and set my board to provide it that voltage instead of the default 1.5v and it should work great.

I'm looking at the Gigabyte GA-EX58-UD5 board with the Patriot Viper DDR3 1600 memory, so changing that one setting should be ok with both I think, unless you think I should do something different.

Anyway, thanks again.

 

[darkguset]

No worries mate, do that, it should be ok. The motherboard just states the 1.5V because that is the default value for DDR3 in the Jedec specifications. But that is a general rule. That does not mean that a memory module cannot run any higher or lower than 1.5V. It just gives a rough "default" value at which it should operate. Now only the manufacturer would be able to know the exact voltages at which its modules run and are warrantied to.