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Up Topic The Rybka Lounge / Computer Chess / What is the time equivalence for 32-bit compared to 64-bit?
- - By kullboys Date 2018-09-06 02:49
Hello everyone
About twice as long if everything is actually using 32 bit integers for the 64 bit operations.
If the 64 bit operations are emulated using 32 bit integers, it takes twice as many operations.
Of course, the entire body of the program is not involved just in the bitboard operations.
But a lot of it is.

On the other hand, 32 bit code can sometimes take advantage of SSE type instructions.  So we really are using 64 bit operations on a 32 bit machine.
In such a case, the 32 bit code can be pretty close to the speed of the 64 bit code.

So, as a general rule of thumb, I would say that the speed of a 32 bit bitboard program will be between 50% and 75% of the speed of a 64 bit program.

So why would you use a 32 bit program in the first place?  Because you have a 32 bit operating system.  There is no other sensible reason that I can think of.
Thanks.
Parent - - By Labyrinth (*****) Date 2018-09-06 04:16 Edited 2018-09-06 21:44
Sedat Chess has a 980X benchmark, at the same clockspeed 64-bit gets 14790 kN/s, 32-bit gets 10905 kN/s. Edit: percentages were bad, see reply by anst
Parent - - By anst (*) Date 2018-09-06 07:57 Upvotes 1
That is either a 36% increase or a 26% decrease depending on which way you look at it.
Regards
anst
Parent - By Labyrinth (*****) Date 2018-09-06 21:39
Yeah, you're right, I somehow forgot how percentages work : /
Parent - By Vegan (****) Date 2019-02-28 20:24
64-bit has better memory management and with more RAM installed it can allow for literally supercomputer memory sizes
Up Topic The Rybka Lounge / Computer Chess / What is the time equivalence for 32-bit compared to 64-bit?

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