Author: Eugene Nalimov
Date: 11:34:47 01/03/00
Go up one level in this thread
I can assure you that for at least one part of chess program - TBs - 32 bits is too small; for 6 man TBs we need at least 33 bits... And while it is doable at 32-bit machines (or at 16-bit, or even at 8-bit), 64 bits will help a lot. Eugene On January 03, 2000 at 12:35:28, Bruce Moreland wrote: >On January 03, 2000 at 10:43:19, Fernando Villegas wrote: > >>Not too much. F5,16 to Fritz 5,32 was not the great thing in terms of speed >>increment. Seems to me that top programs has reached a point where dramatic >>improvements are: >>a) more slowly >>b) more based in code improvements than in speed progress. >>But I am not a guru and I can be totally wrong. Ask the programmers here. >>Fernando > >In a 16-bit architecture there are issues involving quantities that exceed 16 >bits. You have 65536 unique values that you can stuff into an int. This is >usually enough in a chess program. But going to 32-bits allows you to do a few >things that were a little harder before. > >The big 16-bit issue is memory addressing, because you can only stick 65536 >unique values into a pointer variable. Computers have more memory than this, so >in the Intel architecture how they let you address more is through segment >registers, which are 16 additional bits that you can use to address more memory. > >I'm not going to go into great detail about this, but it's a big deal. >Essentially you get 64K that you can address quickly, and for everything else >you have to use a segment register, which is slower. > >In a chess program you can jam everything into 64K, except the hash table and >maybe some other large and infrequently used data, but you can do more if you >don't have to deal with this. > >In the 32-bit world you don't have to deal with this. You can create new chunks >of data without having to worry about blowing out 64K segments, you can write a >lot of code, and you can deal with ints that have larger values. > >So what you get when you go from 16- to 32-bits is freedom to write more >interesting stuff. You also get a little speedup from being able to throw away >segment registers. And finally, in my opinion you can ditch your assembly code >if you want, since the compilers seem to be much more capable in the 32-bit >environment. > >When you run in 64-bits, you can make bigger ints, but the lifting of code and >data size restrictions are much less important, since no "normal" programs are >anywhere near to blowing out a 32-bit address space. > >For chess applications you can use a 64-bit datatype to assign one bit per >square, which can be either vaguely useful or extremely crucial depending upon >how you architect your program. > >My guess is that most programs are designed to run fine in the 32-bit world, or >even the 16-bit world. These will not benefit much from 64-bit processors. You >can write a perfectly fine chess program without having to take heavy advantage >of 64-bit quantities. If you are starting from scratch perhaps you would make >more use of these, but if you don't have them you can live without them and >suffer very little if at all. > >bruce
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