Anyone teach me something about thread?

[szbxa]

Hi, guys. i wanna learn something about CPU thread and hyperthread stuff. i have 2 questions asking here:

will the applications that do not support multithreat perform the same at 2 cores and 4 cores?(cache, clock are the same)

Do MOST of the applications that supports multi-thread supports hyperthread?

those are what i wanna know. actually i am just waiting 4 i3, and i think the hyperthread supported i3 will have likely the same performance to the i5 750 if the answers of the questions are yes. coz at the sigle thread applications they have the same performance and i3's hyperthread will offer same performance as the i5, right?

 

[hunter315]

A program with 2 threads will perform the same on a dual core as it would on a quad assuming all other specs are equal.

Applications are unaware of hyper threading generally, they just see it as an extra core and make use of it, however a logical core created through hyper threading only performs about 40% as fast as an actual physical core would(That was the number back with the old pentiums it may have been improved) so an i3 with 2 physical cores and hyper threading for 4 logical cores will perform significantly slower than an i5 with 4 physical and logical cores.

 

[belial2k]

take a look at the cpu charts here
http://www.tomshardware.com/charts/2009-desktop-cpu-charts/benchmarks,60.html

take note of the differences between the i5 and the i7 920.

You will see that the apps that are not coded for multiple threads perform about the same, but in the ones that are coded for multiple threads the 920 runs almost twice as fast. But that is running just one app at a time. The difference between quad and dual core is that it allows you to be doing more at once, even if the app is not coded for multiple threads. So you can expect a quad core to still be faster because it has more headroom to be running background task and the main app.

 

[dragonsprayer]

belial = wow you know the difference between a dual and quad!

lol! ... noobie!

if you want a dual turn off 2 cores in the bios!


hyperthreading = over heating slight performance gain ... use with caution with 4ghz plus i7 systems.

i7/920 is the only system too use, you can turn on and off cores and hyperthreading. but you only need that with a few cpu intensive apps like 3d rendering and video encoding.



most applications support only 2 cores, so any cpu will do about the same. the new dual cores intel says are faster are only faster due to the fact the factory overclocking is higher. belial your explantion is useless nobody cares about pentium!

slightly what is that? with some apps what is that! no answer!


go i7920 to game! turn of HT and cores and turn up the speed - that is the answer! with high cpu intensive programs turn on all 4 cores and turn down the speed. add ht and do a performace run. you find it rearely helps it is only for stock speeds and highly cpu intesive 3d apps or number crunching

bye belial......... you mis me?

 

[sminlal]

> will the applications that do not support multithreat perform the same at 2 cores and 4 cores?(cache, clock are the same)
A non-multithreaded application by itself won't run any faster on a dual- or quad-core system than on a 1-core system. But if there are other things going on in your system, the additional cores will let those tasks run without slowing down the application. (And in a modern OS, there's always something else going on.)

> Do MOST of the applications that supports multi-thread supports hyperthread?
Applications don't know anything about the difference between a "real" core and a "hyperthreaded" core. To the application, a thread is a thread no matter how it's run. But an application with two CPU-bound threads running on a single hyperthreaded core will only run about 1.2 to 1.5 times faster than on one core, whereas it will run almost 2 times faster on a true dual-core system. This is because hyperthreading isn't an actual core, but rather uses the unused pipeline cycles of a single core.

 

[szbxa]

> will the applications that do not support multithreat perform the same at 2 cores and 4 cores?(cache, clock are the same)
A non-multithreaded application by itself won't run any faster on a dual- or quad-core system than on a 1-core system. But if there are other things going on in your system, the additional cores will let those tasks run without slowing down the application. (And in a modern OS, there's always something else going on.)

> Do MOST of the applications that supports multi-thread supports hyperthread?
Applications don't know anything about the difference between a "real" core and a "hyperthreaded" core. To the application, a thread is a thread no matter how it's run. But an application with two CPU-bound threads running on a single hyperthreaded core will only run about 1.2 to 1.5 times faster than on one core, whereas it will run almost 2 times faster on a true dual-core system. This is because hyperthreading isn't an actual core, but rather uses the unused pipeline cycles of a single core.

thanks everyone, everybody gave me a clear answer, but i like your format.