〜が早いか

席(せき)に座(すわ)るが早(はや)いか、眠(ねむ)ってしまった。

Seki ni suwaru ga hayai ka, nemutte shimatta.

No sooner had he sat down than he was asleep.

が早いか stresses near-simultaneity, more emphatic than や否や

チャイムが鳴(な)るが早(はや)いか、教室(きょうしつ)を飛び出(とびだ)した。

Chaimu ga naru ga hayai ka, kyōshitsu o tobidashita.

The chime sounded and he was out of the classroom.

It paints someones haste, with a touch of caricature

書き言葉(かきことば)専用(せんよう)で、会話(かいわ)では聞(き)きません。

Kakikotoba senyō de, kaiwa de wa kikimasen.

Written only; you do not hear it spoken.

All three in this set are like that — recognising them is enough