How come my system memory is not consistent?

[dn7309]

My RAM is supposed to be DDR3-1600 and I set it in the BIOS to run at 1600mhz, but CPU-Z said otherwise. If you look at the screen capture below, the top window said I run at 800mhz (which is 1600 mhz at double data rate), but the windows below read that my max banwidth is at 667 mhz 😵

 

[Blain]

My RAM is supposed to be DDR3-1600 and I set it in the BIOS to run at 1600mhz, but CPU-Z said otherwise.

CPU-Z F.A.Q.
"If the computed bandwidth is lower than the one specified on the memory module, that means that the SPD information on the module is not correctly programmed, or most likely that the bandwidth is not given at the default memory voltage, but at a voltage defined in an extended profile (EPP or XMP)."

 

[bryanl]

Defaulting to the XMP profile is not the safest practice, owing to the more lax testing done to determine it, so most motherboards default to JEDEC profile, i.e., the actual ratings of the RAM chips. DIMMs made with JEDEC 1600 MHz chips aren't expensive or hard to find, the best being advertised for 1600 MHz, rather than faster speeds. They tend to look plain.

 

[dn7309]

So what does it mean? Corsair advertise it as 1600mhz even though it 1333mhz. so the model is only 1333mhz, but can theoretically go up to 1600mhz if you are willing to mess with the latency and voltage?

 

[bryanl]

It means quality standards for memory are low, both with stick manufacturers and retail customers. Somewhere there's a thread where one person says a certain brand is better than another since it's made with 1600 MHz chips rather than the usual 1333 MHz chips, and they're talking about 2133 MHz sticks.