Hi-

Google the program CPU-Z. Download it to you computer and run it. Go to the SPD tab. It will show you the manufacturer, serial number and part number of the ram installed in your computer.

I think you can also run the dell support application and look up the information of what is actually installed in your computer. One of the items listed is the ram (memory) information.

For example, I have a 16gb stick in one slot of my computer of Samsung ram. The other slot is currently empty. You can have a maximum of 32 gb, 16gb per slot. The computer has 2 slots for ram.

google M378A2K43CB1-CRC and that will show you for example what ram stick in my Inspiron 5675. I have the 1800X processor.

I don't believe you can speed up the ram to run faster in the Inspiron 5675. I think Dell has it locked somehow.

Below are the Dell validated OEM memory sticks for the Inspiron 5675 Desktop. Call Dell Spare Parts 1-800-357-3355 and ask for price and availability.

H14WP 16GB,2400MHz,PC4‑19200,2RX8,DDR4,Dual Rank,Unbuffered,1.2v,Non-ECC, Samsung M378A2K43CB1-CRC

2J55C 8GB,2400MHz,PC4-2400T,1RX8,DDR4,Dual Rank,Unbuffered,1.2v,Non-ECC, Micron MTA8ATF1G64AZ-2G3H1R

The max memory speed for Inspiron 5675 is 2666.  You need memory that has a JEDEC SPD profile for that speed (Intel XMP is not supported).  As you have found most memory only has a JEDEC SPD profile of 2133. The thread below lists some options.

https://www.dell.com/community/Desktops-General/Fastest-Memory-for-Inspiron-Gaming-Desktop-5675/td-p/5127755

For my system I got a matching Samsung M378A1K43CB2-CRC memory stick off of eBay.

Ok I had read the information about how the motherboard reads the chip before, what program are you using to determine the speed your Ram is actually operating at?  My 5675 came with a single Kingston 16 gig installed, yippee i thought i probably had two 8s but i was very happy when I opened the case to install an M2 and saw what I had for ram.  chip came in 5675

I looked and looked but could not find an identical chip kingston lists only one product in 16gb for this machine  had a rough time even finding one of those but finally located one on ebay.  Everything runs but I do not know if they are running full speed someone let me know what they are using to test memory speed so i can check for myself.  I run black desert online as one of the most demanding things I do with this machine, it just loves that nvme m2 and the extra ram also seems to make things much smoother.  

Hi-

 Google up CPUID CPU-Z. It is a program you can install on your machine and it will tell you a lot of information about your machine.  Click on the MEMORY and SPD tabs, they will give you all the information about your ram chips. The program is free.

@suemccartin Could you give more details on the Kingston model installed?

The picture a few parts up is the chip that came with the machine.  I went to the Kingston web page they list one and only one as approved for the 5675 I think they called it Dell gaming or something.  I ordered that one everything is fine cpuz verifies memory speed is where it should be.  I had to hunt but I ended up paying 190.00 for the 16 gig chip (aak outrageous).

As mentioned by lost savage, the Inspiron 5675 has a maximum ram speed of 2666mhz, only achievable if the ram has an 'SPD' profile of 2666mhz. After browsing this thread and the other one linked to by Lost Savage, I finally went with the Adata Gammix D10 2666mhz. It booted right up and runs at the right speed out of the box. 

For some light reading, AMD lists a known collection of ram that runs with its Ryzen chips on an AM4 motherboard here: https://www.amd.com/system/files/2017-06/am4-motherboard-memory-support-list-en_0.pdf

So you could just scroll to the DDR4-2667 category and choose from those options. The Kingston HyperX, Adata and Corsair are all listed. Again, the key is to avoid ram without a specific SPD profile. Corsair's SPD of all their ram is set at 2133mhz, regardless of their "tested speeds" that exceed 3000mhz and beyond. Adata's Gammix line is the only one of their Ram that has an SPD profile set to 2666mhz. The HyperX also has an SPD of 2666mhz.

*Word of warning, don't buy the 2400mhz versions! You must buy the 2666mhz versions in order to get the 2666mhz SPD. This isn't explicitly mentioned anywhere on these websites, so I felt it should be mentioned.

*Also, Dell support will always tell you 2400mhz is the maximum speed because that's what all their official documentation lists. They can't go outside of that, so it's up to us to experiment. Luckily, we have forums like this!

There are Clues 

This is what the label says

16GB 2Rx8 PC4 2400T UB1 11
KYXC0V                MIH$17405AND8

DDR4 UN Buffered 2400

 CRUCIAL is a Dell partner and guarantess specific parts to work

http://www.crucial.com/usa/en/inspiron-5675/CT10638697

Crucial 16GB DDR4-2400 UDIMM

I have a slightly different RAM manufacturer from the others listed, See my screen captures below from CPU-Z

I get the exact same information from CPU-id no mater what memory I use.

I have tried:

PNY Anarchy-X 16GB (2x8GB) 3200MHz DDR4 Desktop Memory - Red MD16GK2D4320016AXR

and

G.SKILL Fortis Series 16GB (2 x 8GB) 288-Pin DDR4 SDRAM DDR4 2400

So am i truly getting only getting a max of 1197mhz from my ram no mater what?

suemccartin,

Click my name and private message me the pc service tag number.

Well,
I spoke to soon. After a shutdown overnight I have given up on running both ADATA sticks at the same time. The blue lights and fans come on but no signal to the display via the RX-580. The blue lights usually did not come on 2 days ago. I did get a Kingston 8GB and ADATA 8GB combo to work, and timings etc seemed ok in HWinfo, but they also failed a shutdown and restart. I should note that the ADATA 8GB x 2 combo did survive a hibernation previously. Currently even the single Kingston 8gb is not working. Will toy with this later and likely return the ADATAs. Such is life.....