Originally Posted by ayyini
I'm building a new rig as a basic office machine and was RAM shopping today when I noticed something interesting. The CPU in the new system will likely be a Pentium G620 which, according to the specification from Intel
, only supports up to DDR3-1066 RAM. That seemed really low, so out of curiosity I pulled up the specs on my i5-2500k
. It says it only supports DDR3-1333/1066! I've been running 1600 for over a year and it's easily the most commonly recommended speed around here. Are Intel's specs inaccurate? I've seen people say they're running speeds even faster than 1600, and I've seen it in memory benchmarks as well. Can someone explain the discrepancy between Intel's official memory support and actual real-world usage?
Secondly, I will probably be using my current rig's RAM (4GB DDR3-1600 7-8-7-24-1T 1.6v) in the new system and just getting 8GB for the bigger machine. If the G620 can handle the 1600 speed I'll just leave it as-is, but if it can't I'll just downclock it to 1333 or 1066 and drop the latencies even further. Any recommendations on settings? Stability aside, how low can
The specs are accurate, but it's the motherboard that determines the maximum speed supported. So with the G620 in a motherboard that supports memory above 1066 MHz (like maybe up to 1866 MHz, I guess), if even 1333 MHz memory is installed, then it'll default to 1066 MHz. This requires the user to manually bring the memory up to its stock speed.
So with the i5-2500K's maximum supported of 1333 MHz, any memory that gets installed that's faster than that will default to 1333 MHz. So it's the same thing: this requires the user to manually bring the memory up to its stock speed.
However, some motherboards (especially the kind of boards many of us here on OCN prefer to buy) won't work exactly like that due the way the manufacturers designed them. For example, I have an i5-2500K, the P8P67 EVO, and 1866 MHz memory. When I turned my system on for the first time, it defaulted to 1600 MHz. So I checked the motherboard's specs, and found this:
This is an interesting design to me because it looks like they designed it around the more common memory being purchased at the time this board was released, which was 1600 MHz. That way people could just put their 1600 MHz memory in and be done with it instead of wondering why it's running at 1333 MHz.
The "O.C." is a fancy way of saying that if memory is installed that's faster than 1600 MHz, then it must be manually brought up to its stock speed.
Edited by TwoCables - 7/4/12 at 8:04pm