Added an extra 1Tb M.2 SSD, now all my programs take ages to open. Why?

Hi

I recently rebuilt my computer with a new motherboard, CPU and graphics card and all was going swimmingly.

It's an MSI Z790 Gaming with Wifi, Intel Core i7 14700K CPU and a GeForce 3060 GPU with 12Gb. System is also running 32Gb DDR5.

Windows version is 23H2 running on a 1Tb M.2 SSD

I am a professional wedding photographer and the computer really only runs editing running predominantly, predominantly Lightroom, Photoshop, Photo Mechanic etc.

For extra storage and speed, I decided I wanted to add another M.2 SSD, so added a Crucial P3 Plus 1Tb M.2 SSD to the third slot of my motherboard (the board can take 4 x M.2 slots).

When I did this and initialised the disk, I suddenly found that programs like Lightroom etc all started to slow down significantly.....so much so that when trying to load them, it would take up to 4 mins at a time for Lightroom to even become usable.

Is there a reason for this? Why would the addition of an SSD SLOW the computer down? I would have imagined it would have had at LEAST no effect on this as it's purely storage, nothing else? And the board is relatively decent and should be able to take 4 M.2 SSD's.

I do have an older 250Gb M.2 SSD in the second slot on the motherboard, so I am wondering if I am overloading the motherboard? Or is there something I need to configure, maybe in BIOS?

I am a total complete computer idiot when it comes to this detailed kind of thing, so any help would be really grateful. Thank you!

Connecting M.2 SSD is the way to speed up application startup time try different M.2 slot or maybe you did not connect the M.2 SSD securely check that as well.

Which M.2 slots are used can also be important to speed of programs loading.
Check your manual and your BIOS setting options.
In many cases, the data lanes used by the slots are altered in number of lanes available to any one slot when one introduces a new M.2 device. (Especially if the device is not the same generation as the other on the Motherboard.)

your motherboard might have a limitation on speed and pci bandwidth depending on how many sata drives you have connected, as well as combined with nvme. Check your motherboard manual for information to see if your limiting yourself.

You could also run something like crystal disk mark with the drive not connected and with it installed to see if the speed is being affected.

You should also enable AHCI mode from BIOS, you need to select SATA Mode and switch to AHCI.

I have a Desktop with a 512GB NVMe M.2 and added a 2TB SATA HDD, no speed issue accessing files on it. The HDD is 7200RPM.

That's certainly not something I would expect you to see. Even if you did drop speeds a bit on the PCI Express bus due to the number of devices connected, it shouldn't be something that would slow down loads of applications like Lightroom to take up to 4 minutes to become usable.

I would certainly do some testing on that new SSD if you can? For example, I would drop it in a test box (as I have extra) and would run it by itself just to make sure that it works as expected.

I would remove the drive from your current setup to make sure that speeds immediately return back to normal.

I would update BIOS, chipset driver and check whether M2 is not damaged.