2 ms·
> Assume FP64 units are ~2-4x bigger. This is wrong assumption. FP64 usually uses the same circuitry as two FP32, adding not that much ((de)normalization, most
by thesz 8mo ago
> Assume FP64 units are ~2-4x bigger.
This is wrong assumption. FP64 usually uses the same circuitry as two FP32, adding not that much ((de)normalization, mostly).
From the top of my head, overhead is around 10% or so.
> Why would gamers want to pay for any features they don't use?
https://www.youtube.com/watch?v=lEBQveBCtKY https://www.youtube.com/watch?v=lEBQveBCtKY
Apparently FP80, which is even wider than FP64, is beneficial for pathfinding algorithms in games.
Pathfinding for hundredths of units is a task worth putting on GPU.
- kbolino 8mo agoHas FP80 ever existed anywhere other than x87?
- Paul_Clayton 8mo agoThe Motorola 88k and 68k both supported (eventually) extended precision, and, of course, Itanium supported it for x87 compatibility. https://en.wikipedia.org/wiki/Motorola_88000 https://en.wikipedia.org/wiki/Motorola_88000 (under "Registers": "32 80-bit (88110 only)") https://en.wikipedia.org/wiki/Extended_precision https://en.wikipedia.org/wiki/Extended_precision (see section titled "IEEE 754 extended-precision formats")