Just to note:
When paired with a DRAM controller typical of the period the 68030 usually takes about five or six clock ticks to read a 32 bit quantity from RAM. If we assume 5 clocks then the maximum memory bus performance of the SE/30 is: 16Mhz X 4 = 64MB / 5 = 12.8MB/s. (It might be interesting to write an assembly benchmark to test this, I got these figures from the datasheet of a DRAM controller used in some contemporary computers.) So even if you could interface, with zero wait states on a full 32 bit wide bus (the 53C80 is an 8 bit chip) a fast/wide SCSI controller the SE/30's RAM would be the bottleneck during sustained reads from cache. (And this is assuming the controller's using DMA, rather than depending on the CPU to do a load/store/write operation for each byte/word. Does the SCSI driver implementation in the SE/30 even support DMA? Pretty sure most of the early Macs used PIO.)
The theoretical speed of the SCSI chip in the SE/30 is about 3MB/sec. I don't know exactly how fast the bus that Apple hung it off of is, but honestly, I'd be surprised if the SE/30 could even saturate that 3MB/sec running flat out. Don't really see the point of trying to sub something faster there.
When paired with a DRAM controller typical of the period the 68030 usually takes about five or six clock ticks to read a 32 bit quantity from RAM. If we assume 5 clocks then the maximum memory bus performance of the SE/30 is: 16Mhz X 4 = 64MB / 5 = 12.8MB/s. (It might be interesting to write an assembly benchmark to test this, I got these figures from the datasheet of a DRAM controller used in some contemporary computers.) So even if you could interface, with zero wait states on a full 32 bit wide bus (the 53C80 is an 8 bit chip) a fast/wide SCSI controller the SE/30's RAM would be the bottleneck during sustained reads from cache. (And this is assuming the controller's using DMA, rather than depending on the CPU to do a load/store/write operation for each byte/word. Does the SCSI driver implementation in the SE/30 even support DMA? Pretty sure most of the early Macs used PIO.)
The theoretical speed of the SCSI chip in the SE/30 is about 3MB/sec. I don't know exactly how fast the bus that Apple hung it off of is, but honestly, I'd be surprised if the SE/30 could even saturate that 3MB/sec running flat out. Don't really see the point of trying to sub something faster there.