Memory appears to be running really slow

imrazor

New Member
I recently purchased a 'new' laptop, an open box Dell Inspiron 7586. It came with a single stick of DDR4-2666 RAM, so I decided to pull the dual channel set from my old, semi-functional laptop and put it in the new notebook. The old laptop had a pair of 8GB DDR4-2400 RAM, so I thought the memory controller would just downclock to 2400/1200 MHz, but I'd still get a much higher effective speed with a dual channel set up. That doesn't appear to have happened.

Instead the memory is showing up as a speed of 665MHz, or about 1333MHz when double data rate is accounted for. Can this possibly be right? See attached log.
Code:
Memory --------------------------------------------------------------------

[General information]
  Total Memory Size:                      16 GBytes
  Total Memory Size [MB]:                 16384
[Current Performance Settings]
  Maximum Supported Memory Clock:         1200.0 MHz
  Current Memory Clock:                   665.2 MHz
  Current Timing (tCAS-tRCD-tRP-tRAS):    10-10-10-28
  Memory Channels Supported:              2
  Memory Channels Active:                 2
  Command Rate:                           1T
  Read to Read Delay (tRD_RD) Same Rank:  4T
  Read to Read Delay (tRD_RD) Different Rank: 4T
  Read to Read Delay (tRD_RD) Different DIMM: 7T
  Write to Write Delay (tWR_WR) Same Rank: 4T
  Write to Write Delay (tWR_WR) Different Rank: 4T
  Write to Write Delay (tWR_WR) Different DIMM: 7T
  Read to Write Delay (tRD_WR) Same Rank: 8T
  Read to Write Delay (tRD_WR) Different Rank: 8T
  Read to Write Delay (tRD_WR) Different DIMM: 10T
  Write to Read Delay (tWR_RD) Same Rank (tWTR): 19T
  Write to Read Delay (tWR_RD) Different Rank: 16T
  Write to Read Delay (tWR_RD) Different DIMM: 6T
  RAS# to RAS# Delay (tRRD):              4T
  Refresh Cycle Time (tRFC):              234T
  Four Activate Window (tFAW):            16T
 

Martin

HWiNFO Author
Staff member
That information should be correct, you might double-check with some other tool like CPU-Z.
 

imrazor

New Member
Instead of looking at the static configuration tree, I took a look at the real time data. I found that the memory speed is constantly switching between 666mhz and 1200mhz. It might be a power saving measure, but even when the system is under full load (video export, etc.) the speed is constantly fluctuating. I really don’t know what to make of it.
 

Martin

HWiNFO Author
Staff member
Oh yes, memory controllers in latest CPUs feature such power management modes and can dynamically switch memory clock/timings, it's normal.
 
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