bob wrote:
With one thread, HT on or HT off will have absolutely no effect. So I am not sure what your point is here... you have two logical processors. One is used, one is not. So how can this possibly do anything useful???
oh apologize here, perhaps I don't explain to me with clarity, we have reached the conclusion that in certain processes the HT can harm, what I meant is that if "an engine", in a single processor, with two logical cores, to use a version deep, it can harm to the yield, we can leave activated the HT, and to force to the engine to use one alone of the processors, that will avoid problems associated to the use of two logical cores and system left "something" useful for other different processes in second plane...
I meant that in that way, HT=on, Cores=1 forced in setup engine, at least we will get that it doesn't harm to the yield, the HT is useful in a great majority of applications, let us say that in 5 of each 10 applications the HT is useful, therefore negotiating the modules in that way doesn't need to give up the HT in all the processes...
When thinking in that way I try to extrapolate that behavior to a processor more complex, as an icore 7, but you were guessed right when indicating that the operating system doesn't go that is to distinguish and it could balance the load incorrectly. Therefore the only thing that I seek with that idea of forcing the number of processors in the setup of the engine, it is that at least, don't harm to the yield in that application and we can have the HT in other different processes.
Only for some old system, but a lot of people have semi-olds cpu that have one core and HT...
bob wrote:
I think it is worthless in the case of chess, period. And in general, it is a poor idea as well. There are some applications that run faster with hyper-threading. There are some that run far slower...
good, I personally think that there is more applications than the HT takes advantage to applications that don't take advantage of it... and some programs exist in those that the improvement is tiny, less than 1%... resume for me: (50% software better, 30 % worthless or zero, 20 worse %... bad result)
for example...
http://www.devhardware.com/c/a/Computer ... 5nm-CPU/2/
in an intel D 955 EE, 2 cores + 2 cores logic... the test super PI, is very good for HT, this cpu have to very good test when we test 3 or 4 programs superpi test.
2 superpi.exe programs
40.484 seconds (intel D 955 EE 2+2cores)
35.813 seconds. (AMD Fx60 2 cores)
but when we use:
4 superpi.exe programs...
53.218 seconds Intel Pentium D 955 EE
74.177 seconds. AMD FX60
Regarding in a normal use, I perceive, but it is a personal opinion that if the processor not this busy one to 100% of the load, when the processor has HT=on, the behavior it is more slight, its answer is more sensitive and more quick to the changes of applications, ...
What is not very appropriate is that to activate the HT in a processor iCore7 takes among 1/3~1/4 bigger consumption of power, if you estimate you some 90 W of consumption max in some reviews, to have active the HT implies among 20-30 W this is a true atrocity.
I think that serious possible to take advantage in a better way the use of the HT, in fact, programs calculate intensive as superpi.exe they take advantage of the HT correctly, but evidently that perhaps is because they are 4 different instances of programs, in those that each one has access different to an area by program and they don't mix among them.
it is possible that the only form of taking advantage of the HT a little, be with the simultaneous load of different engines that uses a different area by process... and is with the ponderyn=off.
The problem more big that find the HT, it is that the system overloads one of the cores (core1+core1virtual to 95%, and leave the alone core2+core2 to 5%), that is a great nonsense...
greetings, THE chat-comunication with you has been very interesting.
Sincerely, Oliver
but it´s this is true ?¡