Arctic, Zalman and Thermaltake made nice aftermarket coolers for cards like these. There is the Arctic Cooler NV Silencer 3 that is compatible with the 5900XT, but I don't know if will fit on yours. There should be something out there compatible. Arctic ones still can be found on the Internet for cheap and are good value 😀

I solved a similar problem with the single-slot GF 6800, where the original cooler is too noisy. I solved this by installing the old AC Twin Turbo Pro, which is probably incompatible with the holes in your GF 59xx (the cross pitch is 75 mm). Compatible with FX59xx should be Acutake DarkVGA https://www.suntech.cz/produkt/77616-acutake- … kvga-rectangle/ or https://www.suntech.cz/produkt/77615-acutake- … graficke-karty/ .

I think a Zalman VF700 AL/CU should be enough. You can get them fairly cheaply with Geforce 9600GT, 8600GT, GT240, HD4670, HD5670.
Gigabyte really liked that cooler and shipped a lot of budget gamer cards with it in the 65-100W TDP range from around 2005 to 2011.
It fits my FX-5700.

Maybe if you look for Sapphire cards, you can find a Zalman VF900 or Arctic Cooling Accelero L2. Those were shipped on HD4600, HD4700, HD4800, HD5500 and HD5600 series graphics cards.

Thanks all for the valuable information, I'll have a rummage through my old and defunct stuff for a cooler that meets the requirements. I'll check in again 😀