Performance - ZuluSCSI/ZuluSCSI-firmware GitHub Wiki

Performance characteristics of ZuluSCSI differ depending on the hardware version.

With debug log messages disabled (debug DIP switch OFF), here is best-case SCSI performance by ZuluSCSI model:

Platform	Read	Write	SCSI bus width
Ultra Wide/Wide SCA	34.6 MB/sec	11.7 MB/sec	16 bit
Blaster	17.5 MB/sec	11.7 MB/sec	8 bit
RP2040	9.5 MB/sec	6 MB/sec	8 bit
V1.1	3.5MB/sec	2 MB/sec	8 bit
V1.0	2.4MB/sec	2 MB/sec	8 bit

Slow SD cards or fragmented image files can significantly slow down read and write access. The use of Speed Class 4 or 6 SD cards may result in the bottleneck being the SD card itself. We recommend using Speed Class 10 or above SDHC/SDXC/SDUC-marked cards.

Seek performance is best if image files are contiguous.

On older, slower computers, particularly 68000 Macs with 8-16MHz CPUs, performance is typically gated by the bandwidth between the local bus, SCSI controller, and/or CPU