English Amiga Board - View Single Post

Promilus · 02 August 2021, 19:36

@videofx - those are different approach for a turbo card. Vampire is based on FPGA (Cyclone III for Vampire 500 V2 version) which handles everything to exactly fit into amiga memory map and CPU softcore acts as enhanced 040/060 alike. So in other words directly after boot you do have everything you could have with Amiga + Turbo + RTG + ...
Use of softcore inside the same FPGA which is (nearly) directly hooked to Amiga also allows fastest possible CPU to CHIP RAM transfers (and FAST2CHIP as well). On the other hand PiStorm is based around emulation of 68k CPU on Broadcom ARM CPU and physical interface is based on FPGA. Since FPGA is hooked to Broadcom with GPIO and not dedicated data/address bus it means there has to be yet another layer of translation. And emulated 68k itself (along with RTG, mass storage) are just application run on RaspiOS so it won't work until OS loads up and obviously will fail if app/os hangs up. PiStorm atm is also much slower (both because it's hardly optimized software emulation and because it's interface to amiga isn't quite as good as softcore<->amiga inside of Vampire).
In other words - PiStorm is budget option for something being cross of emulator and accelerator. Not every amiga fan likes that. Vampire is premium option with decent support and kind of close to metal approach like all the hardware hacks inside most turbo cards. Premium performance means also premium price and pretty long time to delivery.
So if you need turbo ASAP - go with PiStorm, that's pretty safe option with plenty of room to improvement. You hardly can get much more from fixed FPGA on Vampire than it already has. There's distinct possibility PiStorm emulation software will improve it's performance and/or allow use of unused ARM cores to offload certain tasks plus use more on-board peripherals efficiently under AOS (e.g. video core, usb3.0).

02 August 2021, 19:36	#4
Promilus Registered User Join Date: Sep 2013 Location: Poland Posts: 867	@videofx - those are different approach for a turbo card. Vampire is based on FPGA (Cyclone III for Vampire 500 V2 version) which handles everything to exactly fit into amiga memory map and CPU softcore acts as enhanced 040/060 alike. So in other words directly after boot you do have everything you could have with Amiga + Turbo + RTG + ... Use of softcore inside the same FPGA which is (nearly) directly hooked to Amiga also allows fastest possible CPU to CHIP RAM transfers (and FAST2CHIP as well). On the other hand PiStorm is based around emulation of 68k CPU on Broadcom ARM CPU and physical interface is based on FPGA. Since FPGA is hooked to Broadcom with GPIO and not dedicated data/address bus it means there has to be yet another layer of translation. And emulated 68k itself (along with RTG, mass storage) are just application run on RaspiOS so it won't work until OS loads up and obviously will fail if app/os hangs up. PiStorm atm is also much slower (both because it's hardly optimized software emulation and because it's interface to amiga isn't quite as good as softcore<->amiga inside of Vampire). In other words - PiStorm is budget option for something being cross of emulator and accelerator. Not every amiga fan likes that. Vampire is premium option with decent support and kind of close to metal approach like all the hardware hacks inside most turbo cards. Premium performance means also premium price and pretty long time to delivery. So if you need turbo ASAP - go with PiStorm, that's pretty safe option with plenty of room to improvement. You hardly can get much more from fixed FPGA on Vampire than it already has. There's distinct possibility PiStorm emulation software will improve it's performance and/or allow use of unused ARM cores to offload certain tasks plus use more on-board peripherals efficiently under AOS (e.g. video core, usb3.0).