Computer: Dell Optiplex 7010 MT
OS: Win 10 20H2
CPU: i5-3470 3.2GHz
RAM: 16GB
HDD: 1TB WD Blue

I bought this PC last year for about the price of the Windows license. It lives in the basement next to the furnace, where I remote to it from one of my Macs when I need it, which is usually to abuse it with HandBrake. Lately, I've been using it more frequently. When selecting a folder in Explorer, sometimes it would make me wait, saying "Working on it" before it would list the contents.

I looked at the HDD S.M.A.R.T. data, and the spindle spin-up values were out of range, and the HDD was predicting a complete failure by 2024. I know S.M.A.R.T. data isn't necessarily great, but not being one to risk it, I ordered a Crucial MX500 1TB SSD and installed it Friday, using the Acronis software available on Crucial's website to clone the drive. It took me 48 hours to get it done, but I finally got a working drive. It took so long because of the typical PC problems. Needed a Bios update, which didn't work at first. Read internet threads until eyes fall out. Make boot-up media, do BIOS update from DOS, etc... Of course, didn't know this until spending a day trying to get the PC to see the SSD. You know, the typical, frustrating, try everything twice, kinda stuff.

My question is about the partition type. Because I cloned the existing 1TB WD Blue drive to the SSD, the partition type is MBR. The Acronis software states that a GUID partition would be better for a SSD, but that wasn't an option because I was doing a direct clone. Is it worth it for me to go through the hassle of converting the MBR partition to GUID? What does GUID do for the SSD that MBR doesn't? I have backed up the whole system to my Synology, and could redo the SSD with the new partition and restore without too much trouble, in theory. It would probably take me five hours or so to get it done.

Also, I have installed a spare 6TB Seagate Ironwolf I had into the Dell, which is obviously a GUID partition, being greater than 2TB. Is there an easy way in Windows to make it a bootable drive? There's nothing currently on it except some scratch files. Do I need to basically clone the startup SSD to the HDD and then expand the volume out to 6TB? Will the free space be contiguous, or will I have to deal with that hassle? I've been fooling around with Macs for so long now that I've gotten soft. I'm so used to using SuperDuper! to clone drives on a Mac and setting the startup disk in settings that I don't have my PC mojo like back in the day.

Any thoughts are appreciated.

The short answer is to use GPT partitions for volumes larger than 2TB and for bootable UEFI installations.
It is not inherently better for SSD vs a spinning drive.

smschulz, I was hoping you'd show up. OK, so I should just leave my SSD alone since it's working now and it's less than 1TB? I was hoping that was the answer.

Basically, yes it will be fine.
If you get energetic and want to a new from scratch installation and your BIOS supports it then create the install with a GPT partition at that time.
That's a lot of work (backup data and reinstall all applications) but technically it would be better.
Otherwise the 1TB MBR will be just fine.

Success! In case anybody else is curious, I was able to switch from MBR to GPT in just a few minutes. Kudos to Microsoft for including the utility with the OS. Just be sure your PC supports UEFI boot before doing this. From the command prompt with admin privileges, the command is:

mbr2gpt /convert /disk:[enter your disk number here] /allowFullOS

Full Instructions
https://www.makeuseof.com/tag/...ert-mbr-gpt-windows/

Yes, you can convert MBR Disks to GPT.
However, if this is a boot disk and your computer is using legacy BIOS it is not always the best decision.
I do not think Microsoft supports or recommends it.
UEFI boot supports both a MBR but is optimized for GPT.
The real benefit again is for UEFI boot drives and to use larger than 2TB disk/partitions effectively.