SD card running slow. How can i fix so i can access folders to transfer files off before formatting?

[SirMoeHimself]

So here's the situation I have, and I'll try to be succinct. I recently upgraded phones (from an S7 to an S10) and also upgraded Sandisk SD cards. My goal is to have the S7 with the previous SD card inside, to serve as a backup device that would be on wifi (like if my S10 was charging i could grab the S7, nothing big.) The previous Sandisk SD card I've had for a while, however lately ive noticed the card having some issues while in the S7. This includes folders taking longer than usual to provide thumbnails and sometimes open, files when opened would open much slower (a PDF file instructional book for my watch I have took very long to show each page) and the more concerning, some folders with images/pics would show partially or fully blacked out pics. However when i plugged the SD card into my PC, those blacked out pics were showing just fine off the phone. Yet even on the PC, this SD card would run slow and some folders opening very slow as well. So id say the card has an issue, could even be corrupt. So before I go on, I have decided to format the card, which I have done in the past and usually helps solves the issues. I've managed to transfer just about everything to my PC and then back onto the new SD card and into my new phone except for pics from the DCIM folder. However, my issue is the picture/DCIM folder, which has around 1000 pics in it, seems to be the problem folder. My plan was to plug the SD card into the PC, and go through that folder and delete any nonsense or useless pics (there are a lot of those) and transfer the ones i want to keep. So like, a pic of behind the couch to see where a napkin fell: delete, a pic of me and my buds: keep. As i said before, when plugging the SD card into my PC, that folder took a very long time to open and load each pic. That Green bar would keep loading, then clicks on the folder would get a "Not responding." Furthermore, every time I try to eject I get the "still in use" no matter what programs I close, so I have to restart the computer, which somehow works so I can successfully eject it. I even did the right click/properties/tools on the SD card, and both the check and scan drive option reported no errors, but i havent run chkdsk yet. Needless the say, there is an issue with the card, but I know a format will fix it, and I'd like to have that card back in the S7 with only certain files back in it. But before i format it, i have to access that DCIM folder to go through the pics, but that folder just loads very slow or not at all. So, my question is, what would be the best way to fix this card so I can access that pic/DCIM folder and go through to delete or transfer pics? Would it be better to do so on the S7? Or run chkdsk or something else on the PC to make it run smoothly? Should I delete other files off the SD card (since everything is still there) to perhaps help it load better? Like I said, I want to format the card but I have to access that folder first. Thanks in advance for any info given and I'm happy to provide more info myself for assistance.

 

[Mr Bojangles1]

What is the storage on the card and how much of it is being used?