Inspiron Desktops

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Dell Inspiron 3891 RAM Upgrade Question

Hello, I recently purchased a Dell Inspiron 3891. It came with 12 GB RAM - 1 8 GB stick + 1 4 GB stick. I was wanting to upgrade the 4 GB to another 8 GB to get the total RAM to 16 GB, but something has confused me that I need help with.

My 3891 has an Intel 10th Generation Core i7 10700 processor (8-Core, 16M Cache, 2.9GHz to 4.8GHz). Looking for the right kind of RAM memory, I read this here:

https://www.dell.com/support/manuals/en-us/inspiron-3891-desktop/inspiron-3891-setup-and-specificati...

"NOTE 2933 MHz speed memory modules are only available for computers that are shipped with 11th Generation Intel Core i5/i5F/i7/i7F processors."

But according to my invoice, my 3891 came with "12GB, 8Gx1 + 4Gx1, DDR4, 2933MHz".

So, apparently Dell shipped to me a 10th Gen Intel PC with 2933 MHz RAM that Dell says should only be used with 11th Gen Intel CPUs.

So which is correct here? I need to know so I get the proper RAM upgrades for my PC. Any feedback here would be great!

Solution (1)

Accepted Solutions

recent user complaints are if bios is updated you would not be able to use 2x16 GB that used to boot in this model on previous bios.  you would have to use one of the Dell stock ram (8 or 4 gb) along w new ram to boot.  so beware do not update bios if you can help it.

Dell spec says 

● 4 GB, 1 x 4 GB, DDR4, 2666 MHz, 2933 MHz
● 8 GB, 1 x 8 GB, DDR4, 2666 MHz, 2933 MHz
● 8 GB, 2 x 4 GB, dual-channel, DDR4, 2666 MHz, 2933
MHz
● 12 GB, 1 x 4 GB + 1 x 8 GB, DDR4, 2666 MHz, 2933 MHz
● 16 GB, 1 x 16 GB, DDR4, 2666 MHz, 2933 MHz
● 16 GB, 2 x 8 GB, dual-channel, DDR4, 2666 MHz, 2933
MHz
● 32 GB, 1 x 32 GB, DDR4, 2666 MHz, 2933 MHz
● 32 GB, 2 x 16 GB, dual-channel, DDR4, 2666 MHz, 2933
MHz
● 64 GB, 2 x 32 GB, dual-channel, DDR4, 2666 MHz, 2933
MHz

2933 MHz, 2666 MHz
NOTE: 2933 MHz speed memory modules are only
available for computers that are shipped with 11th
Generation Intel Core i5/i5F/i7/i7F processors.

this means the same ram runs at two different speed depending on your cpu.  for 10th the bios will make ram run at 2666, for 11th at 2933.  even though your ram spec says 2933, when it is used with your 10th gen cpu, it will be downclocked to 2666.  Dell does not sell two different ram in this model.  it is the same ram whether cpu is 10th or 11th.  but this ram can go up to full speed of 2933 only with 11th gen cpu.

 


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Replies (6)
2 Bronze

Hello, my last posted question was marked by this site as spam, and therefore not included for public viewing. Testing this now.

OK, it was included in the forum. So, my question is: I am wanting to upgrade the RAM in my Inspiron 3891 PC. It has 12 GB, but I would like to upgrade to as much as 32 GB of RAM. Dell says that 2933 MHz RAM should only be used for 11th Gen i7 CPUs - I have 10th Gen i7 CPU, but my PC invoice shows I have 2933 MHz RAM. So is this correct or not?

Doing some reading, I see that the MHz may not matter - even if you install 2933 MHz or 3200 MHz RAM, if the CPU only uses up to say 2666 MHz then it only used 2666 MHz from the 2933/3200 MHz. Sort of like how USB 3.2 will only use 3.1 transfer speeds if the USB port only supports 3.1 transfer speeds. Is this correct? I just want to make sure I get proper RAM sticks for my PC. Thanks in advance for any help you can give!

recent user complaints are if bios is updated you would not be able to use 2x16 GB that used to boot in this model on previous bios.  you would have to use one of the Dell stock ram (8 or 4 gb) along w new ram to boot.  so beware do not update bios if you can help it.

Dell spec says 

● 4 GB, 1 x 4 GB, DDR4, 2666 MHz, 2933 MHz
● 8 GB, 1 x 8 GB, DDR4, 2666 MHz, 2933 MHz
● 8 GB, 2 x 4 GB, dual-channel, DDR4, 2666 MHz, 2933
MHz
● 12 GB, 1 x 4 GB + 1 x 8 GB, DDR4, 2666 MHz, 2933 MHz
● 16 GB, 1 x 16 GB, DDR4, 2666 MHz, 2933 MHz
● 16 GB, 2 x 8 GB, dual-channel, DDR4, 2666 MHz, 2933
MHz
● 32 GB, 1 x 32 GB, DDR4, 2666 MHz, 2933 MHz
● 32 GB, 2 x 16 GB, dual-channel, DDR4, 2666 MHz, 2933
MHz
● 64 GB, 2 x 32 GB, dual-channel, DDR4, 2666 MHz, 2933
MHz

2933 MHz, 2666 MHz
NOTE: 2933 MHz speed memory modules are only
available for computers that are shipped with 11th
Generation Intel Core i5/i5F/i7/i7F processors.

this means the same ram runs at two different speed depending on your cpu.  for 10th the bios will make ram run at 2666, for 11th at 2933.  even though your ram spec says 2933, when it is used with your 10th gen cpu, it will be downclocked to 2666.  Dell does not sell two different ram in this model.  it is the same ram whether cpu is 10th or 11th.  but this ram can go up to full speed of 2933 only with 11th gen cpu.

 


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Community Accepted Solution

Thank you for your response! So, regarding the bios upgrade issue - I have already had a bio upgrade performed. One issue with my 3891 - when I first got it, for a few days (I've only had the PC for about 5-6 weeks now) the screen-saver and sleep mode worked on the PC. Then out of the blue I noticed that they were no longer working. I'd come into my office in the morning, and the screen was still on and brightly lit. There were times in the middle of the night when I went to the restroom, and saw the office lit up in blue, and saw the monitor was still on. Still other times during the day when I left my office to have a meal or watch television, and come back hours later, and the monitor was still on.

I checked my settings, and they were proper - 15 minutes for screen saver, 30 minutes for sleep mode. But hours later the screen was still on.

Then I had a bios update about 3 weeks into having the PC, I installed the update, and the screen saver and sleep modes started working again, and have worked ever since. But now you say that a RAM upgrade might not work with the new bios? And while the 3891 supports 12 GB via 1x8GB + 1x4GB, it does NOT support 24 GB via 1x8GB + 1x16GB. SO the only options for me are to upgrade from 12GB to 16GB, using the 8GB stick that came with the PC? So even though the 3891 supports 32GB and even 64GB, those options are not available to me due to the bios upgrade? That seems to be a very poor business model on Dell's part. Are they working on fixing this issue??

Re: Are they working on fixing this issue?

multiple users of this model are awaiting Dell solution.  given the 3891 is a new model Dell should be writing new bios update and pray they do not introduce a new bug while fixing the current one.

Re:  it does NOT support 24 GB via 1x8GB + 1x16GB

Dell did not validate this config.  that does not mean it would not boot.   you may try but you should try to use Dell oem ram if possible.


@Man With A Box,

I don't know if you have done anything yet, but you might want to just pull the ram out to see what Dell stuck in there.

I had recently purchased a 3891 with 8GB of ram and a 10th gen i3.  After some discussions on this board last month with another member who was very helpful, we figured that Dell was likely installing 3200 MHz sticks in all the machines regardless of processor since, as you noted, they step down to the next multiple speed supported by the CPU anyway.  I took the risk and ordered another 8 GB 3200 MHz stick by Crucial from Newegg for all of about 40 bucks.  I also bought an additional 7200 rpm WD 1 TB hard drive for about 35 bucks to add to the 256 GB SSD that came in the box.  I planned all that as I ordered the PC because I could not customize the order in the way I wanted with the base box configuration.  Sure, I could make some changes, but the way the configurator works, it automatically made other changes such as bumping up the processor, or losing the optical drive, but certainly pricing the end result beyond what I wanted to pay (and the i3 itself was more than enough for my 13-year-old).

When the Dell finally showed up (this was the week of this past Christmas), my additional parts had already come in several days earlier.  I opened up the box and checked the ram.  It was in fact a Samsung 3200 MHz 8 GB stick - model # M378A1G44ABO-CWE.  Both the Samsung and the Crucial stick I bought have a CL of 22.  When I installed the new stick, the machine booted up with no problems.  Of course, the ram is running at 2666 MHz (or 2667 as the Task Manager reports) just as it should with an i3.

Even after the BIOS update that I ran just over a week ago (before hearing of the problems), the PC is still running fine with the ram.

There are several ram suppliers that Dell uses.  But, it seems that to make building the machines easier, Dell simply uses the same speed ram on all machines within the line (the Inspirons in this case) as long as they are the right multiples of what the various CPUs they use supports.

But, double-check your existing ram - there is a sticker on it with the relevant information.  Just match the speed and type, and you should be fine.

2 Bronze

Oh, and just to add, my invoice said the ram was "8GB, 8Gx1, DDR4, 2666MHz", but it was most certainly 3200 Mhz that was installed from Dell.

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