Windows 10: My Old Computer ran faster with spinning disk than my new computer runs with SSD

I have just bought a more modern computer Dell 7050 with 1 terrabyte SSD disk running Windows 10 split into "C" and "D" drivesIt has Intel Core i7 @3.50 ghz and 64GB RAMMy 12 year old Dell Prescision had 0.5 terrabyte Spinning disk running Windows 10 split into "C" and "D" drives32GB RAM operated much quicker than the new machine yet it has only 32gb Ram and IntelR Xeon CPU X5680 @3.33GHZI am at a lost to reason why.I would have the the SSD computer would be much fasterRegards Jeff

:)

 

Old SSD to new computer

I have an old SSD that I would like to install and use on a new computer that already has one SSD and on HD. Windows is installed on the new computer on the SSD. However, windows was also installed on the old SSD I would like to move to the new computer.
When I hook up the old SSD windows will not start and goes to blue screen with options to recover, use different version of windows, etc. As soon as I disconnect it, windows boots right up again. How do I format the old one to get windows off of it to use
it as storage?

 

New Dell Computer and can't dualboot.  

@Tekkie Boy, I'm not mad at anybody. I really appreciate all the help! I ran mbr2gpt and am now having a different problem. @SIW2 mbr2gpt ran successfully. I restarted the computer, went into BIOS, changed boot order as below, then restarted computer again. The system tried to boot from my old SSD, but failed. The error is below (INACCESIBLE_BOOT_DEVICE). What do I need to do to the SSD out of my old computer so the installed OS (Windows 10 Pro) will boot on this new computer? BIOS now shows my SSD as boot option -- top of list (yea, first step).

Boo, Windows will not boot from my SSD.

This is how Disk Management showed my disk BEFORE mbr2gpt conversion (Disk 1).

This is how Disk Management showed my disk AFTER mbr2gpt conversion (Disk 1).

 

Adding an old SSD to new computer

When I got my new computer, I also got another SSD, so now that I am adding the old SSD in addition to my new one and HDD I am not sure what to do. Before I added my SSD from my old one, I reinstalled Windows 10 on it. I do not want to remove it since it
cost me money, so I am keeping it as a backup, however when I open file explorer, I see 4 disks; Local Disk (C, HDD (D, System Reserved (E, and Local Disk (E. The last two have only appeared after I have added the old SSD.

My problem is that I would like to use my old disk for games, yet want to keep another copy of Windows 10. Additionally I don't fully understand why the System Reserved disk shows up and would not like to see it, do you know what I can do?