Topinio, sorry to hear about your Vega 56. Don't sell your 580 short, I plan to shop for one in the near future. I think with a slight under-clock a 580 should make decent points with reasonable temps. Heck, my effort in the next few days will (I hope) be a GTX650Ti, if I can revive my bricked i5-750 or master a Kubuntu 18.04.3 dual boot learning curve!
Damn, I hate typing on my Nook HD+! My browsing laptop also recently bricked.
Ta, sympathies right back at you -- and good luck with reviving your Lynnfield box!
Maybe I'll fire up the 580 after all. (I debated a 5700 XT or a RTX 2060 Super, once Sapphire finally confirmed the Vega was unrepairable and gave me the rebate, but the latter doesn't work with my FreeSync screen and if the former doesn't fold ... maybe I'll get a Vega 64?)
Desktop: E3-1270 v5, X11SAT-F, 32GB, RX 580, 500GB Crucial P1, 250GB Crucial MX500, 4TB 7E8, Xonar DGX, XL2730Z + L22e-20
HTPC: i5-2500K, DH67GD, 6GB, GT 1030, 250GB MX500, 1.5TB Barracuda, Xonar DX, G2420HDB