4 ms·

That's honestly not true at all; it all just depends on your platform. On the Pocket, the FPGA _is_ the processor (there are actually two FPGAs, one for the act

by agg23 3y ago

That's honestly not true at all; it all just depends on your platform. On the Pocket, the FPGA _is_ the processor (there are actually two FPGAs, one for the actual emulation core, and one for scaling video, and there's technically a PIC microcontroller for uploading bitstreams and managing UI). The FPGAs are still not much power compared to the display itself. With the in-built current sensor on the dev kits, the highest we've measured drawn by the main FPGA is ~300mAh. Now this sensor isn't going to be the best measurement, but it's something to go off of.

WhiteDawn 3y ago
Personally I think this is the biggest selling feature of FPGA based emulation. The reality is both Software and FPGA emulation can be done very well and with very low latency, however to achieve this in software you generally require high end power hungry hardware. A steam deck can run a highly accurate sega genesis emulator with read-ahead rollback, screen scaling, shaders and all the fixings no problem, but in theory the pocket can provide the exact same experience with an order of magnitude less power. It's not quite apples to oranges of course, but the comfortable battery life does make the pocket much more practical.
- agg23 3y ago
  When being nitpicky about latency is where FPGAs truly shine. You lose a good bit of it by connecting to HDMI (I think the Pocket docked is 1/4 a frame, and MiSTer has a similar mode) (EDIT: MiSTer can do 4 scanlines, but it's not compatible with some displays), but when we're talking about analog display methods or inputs, you can achieve accurate timings with much less effort than on a modern day computer. For a full computer like the Steam Deck, you have to deal with preemption, display buffers, and more, which _will_ add latency. Now if you went bare metal, you could definitely drive a display with super low latency, hardware accurate emulation, but obviously that's not what most people are doing.
eulgro 3y ago
> ~300 mAh mA? You're not very convincing here.

by agg23 3y ago

WhiteDawn 3y ago

Personally I think this is the biggest selling feature of FPGA based emulation. The reality is both Software and FPGA emulation can be done very well and with very low latency, however to achieve this in software you generally require high end power hungry hardware. A steam deck can run a highly accurate sega genesis emulator with read-ahead rollback, screen scaling, shaders and all the fixings no problem, but in theory the pocket can provide the exact same experience with an order of magnitude less power. It's not quite apples to oranges of course, but the comfortable battery life does make the pocket much more practical.

agg23 3y ago
When being nitpicky about latency is where FPGAs truly shine. You lose a good bit of it by connecting to HDMI (I think the Pocket docked is 1/4 a frame, and MiSTer has a similar mode) (EDIT: MiSTer can do 4 scanlines, but it's not compatible with some displays), but when we're talking about analog display methods or inputs, you can achieve accurate timings with much less effort than on a modern day computer. For a full computer like the Steam Deck, you have to deal with preemption, display buffers, and more, which _will_ add latency. Now if you went bare metal, you could definitely drive a display with super low latency, hardware accurate emulation, but obviously that's not what most people are doing.

eulgro 3y ago

> ~300 mAh mA? You're not very convincing here.