It does seem low, but I doubt the effect on performance would be huge. Certainly not enough to affect the major claims of the paper. For example, on my 4-core

It does seem low, but I doubt the effect on performance would be huge. Certainly not enough to affect the major claims of the paper. For example, on my 4-core machine I just loaded up two instances of Stockfish, one with 32MB hash and one with 512MB, and assigned 2 cores to each. I loaded up a few random middlegame positions, and after analyzing for 1 minute, the evaluations and main lines were generally the same (within the margin of error for repeated runs of the same engine). when analyzing the Kasparov's immortal game, it was a toss-up which engine would find the famous rook sac first. 1GB is probably suboptimal on the hardware they used, but the difference is probably minimal.