Well,since last friday Steam works again. With the last Steamclientupdate came the possibility
to circumvent hwcaps with a inbuild hack in Solus.
Its activated by tipping into the terminal : echo "STEAM_HACK_IGNORE_HWCAPS=1" | sudo tee /etc/environment
Than log out and log in again,then tipp in terminal:
Run sudo ldconfig -X
It works for the time being at least,but i guess future Steamupdates will refine it.