Mac Pro5.1 very slow with SSD, fine with HDD

Thanks for that quick reply. The SSD reports write 227, read 272 MB/s, and the HDD reports write 127, read 122. I hadn't enabled TRIM because Samsung say they have their own version, but I will do that now and report back. Another glitch - I'm getting a message that the backup has failed because there is insufficient room on the backup drive (another 860 EVO in another drive bay) even though it's nowhere near full. I know an SSD isn't ideal as a backup drive, it was just convenient... I have another backup on an external HDD, I will plug that in when this is resolved.

I'll enable TRIM now. Wish me luck, I'm terrified of Terminal...

That didn't go too well... after I enter the command it asks for a password, which I have not set up on this drive (I just press 'return') but it says this is incorrect. I will reboot from another drive that does have a password and try again.

That's very helpful, thanks. I have a MBP I can put the TM SSD in, and revert to using the external HDD - I was backing up to both anyway, the SSD has only been in for a week. I somehow suspected it was a daft idea when I installed it.

I enabled TRIM after booting from the original MX500, and the computer works really well, thanks. I ran Etrecheck and the performance is 'Good'. However, when I boot from the EVO 860 it's still really slow with beachballing and scores 'below average' - this drive was brand new yesterday. The write/read speeds on both SSDs are still the same as before. I just want a working machine so I'm happy to just use the MX500 and find another home for the EVO. I did read somewhere that Samsung SSDs can have issues with TRIM, but I'm not too bothered, I can find another home for it. Many thanks again, I'm sorted.

Firstly, I solved the TM backup problem: it was trying to back up both the internal drives and also a 1TB general backup partition on the 2TB external HDD (the remaining 1TB is the TM destination). I excluded the unnecessary items and it works fine.

DriveDX reports all 3 SSDs to be 100% EXCEPT the 860 EVO. The original MX500 with 2000 hours on-time and the second with 200 hours report 100% lifetime left but the Samsung with only 10 hours has 99%. Possibly a faulty drive?

Actually I'm not bothered by this, only interested. The problem is that, with only the MX500 startup drive and an old HDD installed, the computer still lags by a second or two when typing in Nisus Writer Pro, or moving folders around on the desktop, or browsing - opening a web page takes up to 6secs. Opening one 2.5Mb Macdraft plan takes up to 10 secs, but opening multiple other plans in another folder only takes a few. Opening all the pics in a 549Mb folder only takes 4 secs which to me is pretty quick, there is no lag when moving between pics. Etrecheck rates the performance as 'good'. Do you think reinstalling the OS might help?

Thanks again. As we say here in Norfolk, thaa's a rum 'un. I will restore onto the newer Crucial and try that. Something slightly odd is that Etrecheck reports only 2000 hours use for the MX500 in the report I sent, but that drive was in use since 2019 in my previous MP 3.1 until I got the current 5.1 a couple of months ago, and I use the computer for several hours every day. Here's hoping...

It worked, thanks. I simply restored my TM backup to the newer MX500 and all has been well for a few hours, it's really quick (by my standards anyway).

Thanks again for your patience and all your help. It's been an education.

Thanks, yes Native Command Queuing is enabled, and queue depth is 32. Tomorrow I will run Drive DX on that drive and report back. Thanks again, Alan

Thanks, I'm having trouble uploading it 'cos of the 5000 char limit, and using the 'additional text' button still gives the same message. I'll keep trying...