A new, good video card works worse than the old one.

Hello. I recently bought myself a GTX 550 ti 1gb since my GTS 250 died. I ordered it on Avito, like a good seller. In general, I inserted it, went to test it in games and noticed that the fps on it is less than on the GTS 250. For example: Dota 2 on the old video card pulled 70-80 fps, and on the new one it barely rises above 50. And the thing is it's all frizz. Yes, even in Harris fashion, when you go to the normal server, the game crashes. I don't know what's the matter. The video card passed the furmark test, although it warmed up to 96 degrees but passed (720p test). What is strange, ION does not install the driver (Error code 43), but it works worse with new ones. Now I'm sitting on the drivers that Windows 11 found for me.
My kits:
Mother: N68C-S UCC
Proc: AMD Phenom ii X4 955T
RAM: 4gb 1 bar Samsung ddr3 1333mhz (not overclocked)
BP: I don't remember the name but it's like 500W, like FSP.
SSD 120 gb, HDD 500 gb.
And yes, I know that my PC is something else, then I’ll assemble a computer for myself later