Laptop Memory Query

[Kris55]

SODIMM memory question.

 

I have 2x 16GB CL16 3200 installed in my Legion 5 laptop but is being underclocked to 2667.

 

In gaming am I better off keeping the memory with the underclock or getting some Kingston CL22 3200 32GB Kit?

 

According to their website it will run at full 3200 without XMP

 

Would I have an performance increase or decrease? The latency worries me. 

 

Note: My Legion 5 AMD 5800H Laptop doesn't support XMP and only use laptop for gaming

[mariushm]

No, it will not run at 3200 without XMP / DOCP.  the website is lying.

 

AMD uses a different name for XMP, they use it DOCP or something similar to that name. 

 

If the BIOS doesn't have options to configure the frequency manually or through some profiles, then you're stuck with 2666 Mhz. 

Without bios options, maybe you could find some overclocking utility to overclock the ram on the fly, from within Windows, but no guarantee it would work right. 

 

 

[Kris55]

1 hour ago, mariushm said:

No, it will not run at 3200 without XMP / DOCP.  the website is lying.

 

AMD uses a different name for XMP, they use it DOCP or something similar to that name. 

 

If the BIOS doesn't have options to configure the frequency manually or through some profiles, then you're stuck with 2666 Mhz. 

Without bios options, maybe you could find some overclocking utility to overclock the ram on the fly, from within Windows, but no guarantee it would work right. 

 

 

Thanks Mariushm,

 

What if I was to buy another stick of the memory that came with the laptop - 16GB of Samsung memory that was clocking to 3200Mhz out the box but has the same CL22 rating as the Kingston memory I was looking at.

 

I replaced the OEM memory because of the poor CL rating and wanted 32GB - but on hindsight I could just buy one extra Samsung 16GB stick and use the two at 3200Mhz - if there is not a drop in performance. 

[mariushm]

The CL value, the latency, is not a fixed number.  You get CL22 when running at 3200 Mhz, but when the memory is configured to run at a different frequency, the latency value may change. 

For example, the same memory stick that needs CL22 at 3200 Mhz may only need CL20 at 3000 Mhz and CL18 at 2666 Mhz.  

 

Basically, the higher the frequency, the memory chips on the stick need a bit more time to respond to requests to read or write data into the chips. That's what that CL parameter means. 

 

The bios in your laptop may limit your RAM at 2666 Mhz for various reasons, which could be good reasons or bad reasons... Could be for power saving, to keep the RAM cool and to keep ram's power consumption low,  or it could be simply because they were too lazy and wanted to simplify the bios and remove the options where you can choose to run memory at higher frequency. 

 

XMP/DOCP are basically a list of presets, where each preset tells the BIOS the stick can reach a certain frequency when a bunch of parameters are set to some specific values and the voltage is a specific value.  The stick may have a 2400 Mhz preset , may have a 2666 Mhz preset, may have a 3000 Mhz preset and may have a 3200 Mhz preset. 

 

If the BIOS supports XMP/DOCP, the BIOS goes through all these presets and picks the best preset that it considers safe. In your case, if your BIOS considers 2666 maximum possible, it may look in the presets stored in the ram stick and picks the preset closest to 2666 Mhz and applies those parameters. 

If the BIOS doesn't support XMP/DOCP, it will simply use a built-in preset with more conservative parameters, guaranteed to work with any memory stick. 

 

CPU-Z or Aida64 are tools that will show you these presets stored inside the memory sticks.