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Last reply by 04-22-2022 Unsolved
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2 Bronze
2 Bronze

XPS 8940, RAM from XPS 8930 not working (can't boot)

Hello, I have had an XPS 8930 for 2.5 years. I recently purchased an XPS 8940. I removed two RAM modules from XPS 8930 into my new XPS 8940. When I did that, the XPS 8940 system was not able to boot (nothing on screen), and the orange light kept flashing on the power button, indicating a boot error. Here are the details below.

1. XPS 8930 was purchased with 16GB RAM in 2019. (2 x 8GB sticks pre-installed)

2. In December 2020, I purchased from Amazon two 8GB sticks (Keusuny brand - DDR4 2666Mhz UDIMM PC4-21300). I added them on the motherboard and they worked without a problem.

3. Last month, I purchased an XPS8930 (11th gen Intel i7-11700, Nvidia RTX 3060 Ti) that came with 16GB installed (Micron DDR4-3200)

4. I removed the two aftermarket RAM sticks from XPS8930 and added them to XPS8940. This is when I got the error. I removed the sticks, and then the computer works again.

I read on this forum that the pre-installed RAM in the XPS8940 is 3200 MHz, but performs at 2933 MHz due to the intel processor limitations. I also read that if RAM speed are mismatched then the performance is at the lower speed of the two. Therefore, I expected my computer to perform at 2666 MHz using 32GB RAM. Obviously, I was mistaken.

Can anyone on this thread shed any light on exactly what caused the system to not boot? I called Dell, and they simply said 4x8GB configuration is not supported. However, I have read on this forum that others have managed to make that configuration work. Therefore, before I purchase the "correct" 2-x8GB sticks, I was hoping to understand the precise source of incompatibility.

Thank you

Replies (20)
6 Indium

Dell support is correct that 4 x 8 GB is not supported. But be that as it may the problem is more likely that the aftermarket RAM is not compatible with the RAM that came with the 8940 or with the 8940 in general. Dell systems are picky about RAM and just because it worked in the 8930 is no guarantee it will work in the 8940. The most compatible RAM for Dell systems is from Crucial which by the way is Micron RAM. That RAM can be found here and I would suggest 2 x 16 GB if you want 32 GB of RAM total.




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@sfbayXPS I agree with @JOcean , that your 32 GB configuration is not supported. You did not indicate what your 16 GB memory configuration was in your XPS 8940 whether it was 1 x 16 GB or 2 x 8 GB, but there is only two 32 GB memory configurations supported in the XPS 8940, 1 x 32 GB or 2 x 16 GB.

Re: I removed the two aftermarket RAM sticks from XPS8930 and added them to XPS8940. This is when I got the error. I removed the sticks, and then the computer works again.

Dell configuration by default often uses a single lonely 16Gb ddr4 for 8940 (more common than 2x8Gb dual channel).

Re: purchased from Amazon two 8GB sticks (Keusuny brand - DDR4 2666Mhz UDIMM PC4-21300

Mixing the above pair w presumed single Dell ddr4 16Gb seems to be an odd combo, and no wonder it is rejected by Dell bios.  Dell XPS 8940 is completely bewildered by this odd combo of different ram of different speed, latency settings as well as parity (if you indeed have single 16 gb).

But perhaps you have 2x8 gb Dell ram in 8940?  It is still not recommended to mix Dell ram pair with third party pair, and that is most likely why you got no POST.  Your prior luck of mixing ram in 8930 does not extend to 8940.

Re: I called Dell, and they simply said 4x8GB configuration is not supported. However, I have read on this forum that others have managed to make that configuration work.

Dell support is often clueless. They are incorrect by default.  User benchmark has many examples of validated 4x8GB in 8940.

https://www.userbenchmark.com/PCBuilder?searchTerm=XPS%208940%204x8GB

One example of successful 4x8GB is CT8G4DFRA32A.C8FP 4x8GB

https://www.crucial.com/memory/ddr4/ct8g4dfra32a

here is another BL8G32C16U4B.8FE 4x8GB

https://www.crucial.com/memory/ddr4/bl2k8g32c16u4b


Re: Dell/they simply said 4x8GB configuration is not supported

to give Dell credit, what they actually meant is they have not tested or validated 4x8 Gb Dell ram in XPS 8940 factory configuration.  Since they never did the test, they do not support such configuration.  That statement does not mean it is incompatible.  It only meant you are on your own if you want to do that, whether it would work or not is not supported by Dell (a disclaimer that Dell is not responsible if it did not work), and Dell has no idea whether it would work or not.  


2 Bronze
2 Bronze

@redxps630 @Vic384 @JOcean thanks for your thoughtful responses. I should have mentioned that both my old XPS 8930 and the new XPS 8940 came configured with 2x8GB sticks. So both had two filled and two empty slots. And I am trying to fill the two empty slots with 2x8GB sticks.

 

Regarding what Dell support said, I was referring to another post that I saw on this subject

https://www.dell.com/community/XPS-Desktops/XPS-8940-memory-upgrade-of-2x8GB/td-p/7779679/page/5

It seems you have also participated in this post. Do you see any merit in getting another brand or speed of 2x8 sticks, or should I just throw out my existing 2x8 and replace with new 2x16?

@sfbayXPS I wish I could say that another brand or speed of 2 x 8 GB may work but I have not seen any posts in this forum where 4 x 8 GB works in the XPS 8940.

Re: Do you see any merit in getting another brand or speed of 2x8 sticks, or should I just throw out my existing 2x8 and replace with new 2x16?

It is safer to get 2x16 or 4x8 of a brand and specific model (Dell or non-Dell) that is validated to work in 8940.  If price is similar then go for whatever you like more.

here are user validated 2x16GB.  https://www.userbenchmark.com/PCBuilder?searchTerm=XPS8940%202x16GB
community recommends crucial ram. Crucial says $back if does not work.


8 Krypton

Maybe I missed it, but did you mention if the XPS 8940 will boot when only the RAM from the XPS 8930 is installed in the 2nd and 4th slots from CPU in the XPS 8940, without the Dell XPS 8940 OEM RAM installed? And you should also remove the motherboard battery and press/hold power button on front of XPS 8940 for ~30 sec, reinstall the battery, close up and see if it boots now with XPS 8930 RAM. If it doesn't boot that way, the XPS 8930 RAM isn't compatible with this motherboard.

Even if it does boot with only the XPS 8930 RAM installed, it's possible those two sets of RAM just aren't compatible with each other But there is one more thing to try....

Put one of the XPS 8940's original RAM modules in the slot closed to the CPU. Put the other XPS 8940 OEM module in the 2nd slot from CPU. NOTE: These two slots do not have the same color retention clips.

Now put the RAM from the XPS 8930 in the two empty slots, 3rd and 4th from CPU, again with mis-matched retention clips. Then remove the motherboard battery and press/hold power button on front of XPS 8940 for ~30 sec, reinstall battery, close up and see if it boots now.

FWIW, the XPS 8940 motherboard has an odd quirk about where to install RAM, and putting matched pairs in slots with mis-matched retention clips works while putting matched pairs in slots with the same color retention clips has issues...

 

Ron

   Forum Member since 2004
   I'm not a Dell employee

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