English Amiga Board - View Single Post - Real-world difference between bus speeds

Overmann · 12 December 2018, 09:53

Hi there,

I've been wondering what are the actual difference in performance between the different zorro buses (inkluding fast Zorro II, which is supposedly ZorroIIx2). I've never had a machine with Zorro III but I understand it's bandwith is about the same as VLB, while Zorro II's bandwith is a little less then ISA (which I find surprising).

Does anyone know, or have measured, how the difference in bandwith effect the performance of cards (such as Cybervision 64/3D)? It might be difficult to create an "all-things-being-equal" situation when going from one bus to another as a Zorro II and Zorro III machine will be so different in so many ways, but lets say an A1200/60 with a Zorro II busboard, then in fast-zorro II mode, then an A4000/60 on the Zorro III bus.

Does a Cybervision saturate the Zorro II bus? Would it saturate it in fast-mode as well? Is there really any point in buying an RTG-card for the zorro bus in a machine that could potentially work with a PCI card?

That's just for graphics. I understand that few SCSI cards were made for Zorro III and that the PCI SCSI cards that work with mediator busboards are for some reason capped at about 4mb transfer-rates, but what about other expansion cards like sound/music, videoediting and ethernet?

12 December 2018, 09:53	#1
Overmann Registered User Join Date: May 2014 Location: Norway Posts: 379	Real-world difference between bus speeds Hi there, I've been wondering what are the actual difference in performance between the different zorro buses (inkluding fast Zorro II, which is supposedly ZorroIIx2). I've never had a machine with Zorro III but I understand it's bandwith is about the same as VLB, while Zorro II's bandwith is a little less then ISA (which I find surprising). Does anyone know, or have measured, how the difference in bandwith effect the performance of cards (such as Cybervision 64/3D)? It might be difficult to create an "all-things-being-equal" situation when going from one bus to another as a Zorro II and Zorro III machine will be so different in so many ways, but lets say an A1200/60 with a Zorro II busboard, then in fast-zorro II mode, then an A4000/60 on the Zorro III bus. Does a Cybervision saturate the Zorro II bus? Would it saturate it in fast-mode as well? Is there really any point in buying an RTG-card for the zorro bus in a machine that could potentially work with a PCI card? That's just for graphics. I understand that few SCSI cards were made for Zorro III and that the PCI SCSI cards that work with mediator busboards are for some reason capped at about 4mb transfer-rates, but what about other expansion cards like sound/music, videoediting and ethernet?