Even if your 1050 ti isn't recognized, it should still be running the game. The easy way to make sure is to open deviceconfig (in Documents\Electronic Arts\The Sims 3) and check what it lists in the graphics card info, starting 30 lines down. That's the card TS3 is using.
There's no reason to try to force GeForce Experience to optimize your game. In fact, it would probably be counterproductive for TS3, and it would definitely override any changes you tried to make to your graphics settings. Adjust the settings yourself, and you'll be fine.
There are two approaches to getting a card recognized, and I think your confusion stems from combining the two. The simpler way to do it doesn't even touch graphicsrules.sgr, just graphicscards. The idea is that you let your card borrow the profile of a card that's already in the database. So all you have to do is change the listed device ID (in graphicscards.sgr) of an older card to match your card, and you're done.
Using the Nvidia 580 is fine; it's already listed as an uber card. Weirdly, graphicscards.sgr lists the device ID differently for the 580 than for the others, but it's not going to matter for what you're trying to do. Just change the bolded text in this line:
card 1080 "Geforce GTX 580"
to the device ID of your own card. You can find that ID in deviceconfig, among other places; look for this:
=== Graphics device info ===
Number: 0
Name (driver): Radeon Pro 560
Name (database): AMD Radeon Pro 560 Series
Vendor: ATI
Chipset: Vendor: 1002, Device: 67ef, Board: 0179106b, Chipset: 00c0
Replace the old device ID with yours, and you're good to go. But write it as 0x67ef (that's a zero) just in case it matters to the game.
The result of this is that TS3 will "think" you have an Nvidia 580, but that doesn't matter. It will be using the profile of the 580 in graphicsrules, so you won't have to add a separate entry for your 1050 ti. You'll know the edit worked when you see a in deviceconfig, as shown above.
The last thing to do is to check the texture memory (TS3's name for VRAM) listed in deviceconfig. It's a couple lines down from the device ID and should look something like this:
Texture memory: 1024 MB
If it says 32 MB <>, you have one more edit to make. In graphicsrules, find this, 8-10 lines down:
if ($textureMemory == 0)
seti textureMemory 32
setb textureMemorySizeOK false
and change it to this:
if ($textureMemory == 0)
seti textureMemory 1024
# setb textureMemorySizeOK false
So you're changing the 32 to a 1024 and adding a # and a space in front of setb. This will force the game to recognize your card's dedicated video memory. By the way, a 1050 ti has 4 GB VRAM, not 1, but TS3 can only use 800 MB anyway, so setting it to 1024 MB is fine.
P.S. The comments about patching are irrelevant here. Every time the game patched, it would revert the changes to graphicscards and graphicsrules, so any edits would have to be redone. But the only ways those files would change now is if you ran the Super Patch for some reason, or maybe if you repaired the game in Origin or Steam.
