Resizable BAR / SAM
Also searched as: resizable bar · rebar · sam · smart access memory · above 4g decoding · base address register
What it means
A BIOS-and-driver feature that lets your CPU reach the graphics card's whole video memory at once, instead of through a small window. AMD's version is branded Smart Access Memory (SAM).
More detail
It gives a few percent in many games, a real bump in a handful, and occasionally a small loss in a rare one. The move is to enable it, measure, and only turn it off for a specific game that regresses. You usually have to enable "Above 4G Decoding" in the BIOS first.
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