XPS 8930 only supports PCI-e 3.0, so any NVME SSD plugged into that PCI-e 4.0 adapter isn't going to be as fast as you may expect. 

What's the intention here? Add an SSD for storage or use it as the boot drive, instead of using an existing HDD or smaller SSD as boot drive?

If your existing boot drive is an HDD, do you also have an Intel Optane module in the M.2 slot?  If you have an Optane as cache for that HDD, you could disable the Optane cache in Windows and then replace it with an NVME SSD which you could use as boot drive. 

You may also want to change BIOS from RAID to ACHI before installing any new drives, but this has to be done correctly, or PC won't boot:

1. Open Cmd prompt window, run as administrator
2. Copy-paste this command, which will start Windows in Safe Mode the next time you reboot: bcdedit /set {current} safeboot minimal and press Enter
3. Restart the computer and enter BIOS setup by tapping F2 when you see the Dell screen
4. Change SATA Operation from RAID to AHCI
5. Save the change and exit Setup. Windows will automatically boot in Safe Mode
6. Open Cmd again, as in step #1
7. Copy-paste this command, which will start Windows in Normal Mode next time you boot: bcdedit /deletevalue {current} safeboot and press Enter
8. Reboot and Windows will automatically start with AHCI drivers enabled

@RoHe​ Hi Ron,

You may remember my upgrade saga from earlier this year. Happy to report all is well with the 8930 and the Nvidia RTX 4060!

As part of the upgrades, I did switch the boot drive to a 2TB SSD. I also have 2 8GB HDD inside the case.

The intent here is to add more internal storage. I have been busy with my fashion photography. I just wanted to take advantage of the BF sales.

I also have the space where the original HDD used to reside. Is there a recommendation for an SSD for that space?

Thank you!

Sorry, I don't even remember what I ate for breakfast this morning... ;o))

And I'm confused. Your OP says you're looking for an NVME SSD to fit in your x4 PCI-e>NVME adapter.  Your 2nd post talks about using the empty 3.5" drive bay which would be for a SATA drive. 

The two HDDs you have now are only 8 GB? That doesn't sound right...

You could get any 2.5" SATA3 SSD you want for that empty drive bay. You'll need a 2.5" tray to fit the 3.5" drive bay, if the SSD doesn't come with it, plus a SATA3 data cable. 

If this is for extra storage, you might still consider an NVME SSD for the adapter that you already have.  SSD on adapter in x4 slot may still be faster than a SATA3 SSD.  Just make sure the SSD will work with your PCI-e adapter...

@RoHe​ LOL.

My original question in the first post is if I should get a NVME SSD for the x4 slot or if there is a form of SSD that will plug into that slot without an adapter.

The choice is yours: use the x4 adapter you already have with an NVME SSD or buy a 2.5" SATA3 SSD and put it in the empty 3.5" drive bay using an adapter tray and attach a SATA3 data cable.

Motherboard has three SATA3 data connectors for drives, plus one (white) for optical drive. So all you need to do is confirm you have an available SATA data port on motherboard, and an available SATA power connector cable coming from the PSU for a new 2.5" SATA3 SSD, and get a SATA3 data cable. 

Even if you don't have an unused SATA power connector from PSU available, you could use a Y-SATA power cable splitter to connect two drives to one PSU cable.

So it might come down to relative speed of an NVME SSD in the  x4 slot vs a SATA3 SSD, budget, $/GB, warranty, etc. 

Only you can make this decision. Just don't buy a "no-name" cheapo NVME or SATA SSD.

The intent of my original question was if something like this will work in that x4 slot or if I should go with the adapter route.  Sorry, I wasn't clear. Thanks.

Can I guarantee that SSD will work in your adapter card...no.  You may want to check with their tech support to see what/any experience they may have about using that SSD in an x4 PCI-e adapter card like the one you have.

Both are compatible with PCI-e 3.0 which is what the XPS 8930 uses. So that's a good start.. Adapter card comes with both "standard" and "low profile" mounting brackets so it should fit the XPS 8930 case.