DRAM Frequency crashing

[NAZAR640]

Hello, everyone. Who could help me, my DRAM freq drops to ~665.4 MHz, and then rises to ~1064MHz. Why it happens? my ram: M471A5244BB0-CRC (2pieces). Could it be caused by processor? My proc: Intel core I5-6300u(max freq that it supports is 2133MHz).

[TzortzisG · Accepted solution]

Hello NAZAR640.

I have the same system you have, but with a Kaby Lake CPU (7th gen) -a Probook 640 G3. Your RAM is working exactly as DDR4 RAM is supposed to work.There is no "DRAM frequency crashing" here. DDR4 modules on laptops are meant to lower their frequencies when not used heavily. This jumping up and down of their speeds is normal and usually follows the equivalent throttling of the CPU. If you're wondering why your 2133MHz RAM is actually limited to around 1066MHz, it's because it's not really 2133MHz but 2133MT/s. DDR4 modules are Double Data Rate, and their actual speeds are half of their advertised speeds.

Because your modules are Double Data Rate modules, they perform like they have 2133 speeds -they don't really though. The MT/s you see above is actually the transfer speed of the modules (bandwith). Everything is 100% normal with your system. This is what I get with my similar 640G3 and everything after that which uses DDR4.......

Take care!

* Double Data Rate should not be confused with Dual-Channel, which again has nothing to do with RAM speed. Again the memory bandwith is doubled here, but only because TWO modules are accessed at the same time instead of single-channel mode where one is accessed and THEN the other.

[NAZAR640]

Thanks, for explanation ❤️