I mean...using a discreet card with an APU. About, maybe 2 years ago, I built a system for a friend, similar to the 'Kill Your Console' rig. I managed to save some money by buying an A10 5700 off of Ebay (it worked out half the price of the 5800K as I won the auction at 5am).
Anyhow it has the 7660D the same as the 5800k but clocked a bit less. 384 streams. He has been using a 6570 1GB Asus card off ebay (cost £14 in an auction) it does benefit most games, but still is too weak for 1080p.
I can get an R7 240 with GDDR5 (72gb/s) bandwidth vs 28 of the 6570, for £30 secondhand.
When using crossfire, does the APU use the memory of the card ? Or does the system default to the ram ?
I figure the ddr5 bandwidth if it could be used by the APU in crossfire, would boost games significantly, even though the card is quite weak itself, with 320 streams.