Inspiron 15 3520 ram speed running 2666mhz instead of 3200mhz

According to the manual, the model with no USB-C connector is 2666 MHz only.  Only if you have a USB-C model will 3200 MHz run at full speed.

No -- changing the battery will do nothing for memory speed.

https://www.dell.com/support/manuals/en-us/inspiron-15-3520-laptop/inspiron_3520_ss/memory?guid=guid-e9d2ea83-38a4-431d-803c-96d63c1dbc34&lang=en-us

1. why ?? the inclusion of  usb type c gives a ram higher frequency

someone with a technical answer?? e.g is there a reason apart from 3 cell battery lower power. i.e higher frequency ram consumes more power.

your reply makes sense but here is another hypothesis of marketing i.e  maket segmentation, through product differentiation by adding features to add value for higher profit.

i.e dell has has done this on purpose and components are the same just to make  some prospective customers buy the more expensive usb type c dell model. M

could this also be valid?? e.g bios lock of ram speed at lower clock??

You'd need to talk to the engineers in China who designed the system, and even then you won't get a definitive answer.   They design a system to sell at the price Dell wants.

You can't redesign the mainboard or rewrite the firmware either way, and replacing the mainboard with one having USB will require more than just the mainboard, plus cost more than 50% of what the system did initially, making very little difference in the end. If you need the faster RAM, sell the system and buy one that meets your needs.

actually Dell vostro with same cpu and 3200 ram speed with usb type c  and 4cell 54 wh battery sells for 100 usd more . Product appeared few weeks after having purchased my dell laptop.

might sell it as you suggested

will test if sk hynix module comply with the timings of the intel i5-1235u cpu to run 3200.

Seems that there is no issue with the memory modules to run 3200mhz speed.

Must be a bios rram speed lock or a motherboard design issue as you suggested.

@ejn63​ 

ordered 2 x16 hynix 3200 memory modules and a 54 wh battery. when all arrive will upgrade and test.

I will test fifa 23 capability of this dell laptop with intel 12 gen and dual ram (iris xe) though I doubt it will work very well without 3200 mhz ram capability and or an i7 and or a dedicated onboard graphic chip but I wanted the 3200 feature enabled in order to remove one of the uncertainties for better graphic performance/speed. Seems the task in hand will not be resolved as Dell has made that clear that it is not supported.

Good and bad news compared to a Dell latitude 5430 with same cpu and 32gb ram but with 3200 ram speed.

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Good news

1. 32 gb ram installed successfully 2 x 16gb

2. ram dual  mode enabled

3. Fifa 23 can now work and play

4. Disk mark I was better

5. 2D mark I was better

Bad news

1. still 2666 mhz ram speed and found no way to enable 3200 mhz ram speed.

2. Fifa 23 definitely needs 3200 mhz modules as there is an occasional-motion lag and delay of controller responsiveness

3. had to uninstall dell support assist as it was consuming all my ram and rendering my laptop unresponsive.

4. 93% passmark ram speed of comparative laptop.

5. 3D mark I was 1% lower due to 2666mhz ram module

6. cpu mark I was 56% of total of  alternative dell latitude laptops. This is very strange.

overall I would think that an i7 or an i5-1335u with 3200mhz ram speed would be a better choice though  definitely go with the 120hz screen and i5-1335u cpu ot an i7-1355u if gaming is essential.

Did not comprehend he reason why my cpu mark suffered by 56 of comparative laptop results.

Any remedies o how to increase cpu mark??

Are turbo boost or speedstep turned off??

Are you comparing an i7 Latitude with an i5 Inspiron?

same cpu same video card so it is an i5-1235u dell latitude.5430 

should I enable turbo boost power max to 28w?? 

 Dell has set this to 20w but using the intel extreme tuning utility it can be modified? the default according to XTU is 28w. 

Also turbo boost short power max is set to 39w  which is the default. Max is 55w should I increase this to 55 ??

Test 1: increase turbo boost  short power max from 20w to 28w and decrease turbo boost short power max from 39w to 28w. 

I get about 76% of best test.

Test 1  increased my results but still not enough

What happened to your original Inspiron 3520?

And no, neither system will handle the head dissipated by that much power, even if you set the system to run that way.

still here. I have set both short and long turbo boost to 28w still 76% of best result. cpu temperature rises to 95oC.