3 ms·
https://www.lo-tech.co.uk/xt-cfv3-dma-transfer-mode/ https://www.lo-tech.co.uk/xt-cfv3-dma-transfer-mode/ has some benchmarks for Compact Flash cards on an XT
by andrewf 6y ago
https://www.lo-tech.co.uk/xt-cfv3-dma-transfer-mode/ https://www.lo-tech.co.uk/xt-cfv3-dma-transfer-mode/ has some benchmarks for Compact Flash cards on an XT bus. On a V20+/186+, "rep insb" saves a lot of instruction fetch traffic.
(The page also talks about breaking up DMA transfers, so a Soundblaster on the same bus can do its own DMA often enough)