Hyper threading - BIG WHITE ELEPHANT ?

[Guest]

Hey i wanted to know if anyone out there has noticed much difference with
hyperthreading on or off?

i mean xp pro is designed for 2 processors thats great but HT surely doesnt
split the cache in half so while 1 "processor" is being hammered the other
seems to have no or little load so to me i think HT is a big white elephant
Intel brought out. should have gotten the FX AMD chip.. why oh why did i
leave AMD for Intel!

i think this should be the same for games as not many programs are written
for dual processors..... so i'd be kind of effectivley using 2GHz of my 4 Ghz
prescott


ANy comments welcome!

 

[Yves Leclerc]

Hyperthreading is still new. Better motherboards/chipsets/processors are
coming out soon that should take advantage of HT.

HT originated in the dual-processor (or greater) server motherboards when
two, or more, physical processors were installed. The motherboards were
able to share the cache and RAM successfully. It will take time to have
this on the regular motherboards.

 

[Guest]

hmm im too impacient, why wait everyone buy AMD! the FX chips kick Intell ass
better pipe lines, better at games, intell's are just the work horse now,
george lucas is using AMD's for his pc's they are useing for the star wars
movies

 

[D.Currie]

Hey i wanted to know if anyone out there has noticed much difference with
hyperthreading on or off?

i mean xp pro is designed for 2 processors thats great but HT surely
doesnt
split the cache in half so while 1 "processor" is being hammered the other
seems to have no or little load so to me i think HT is a big white
elephant
Intel brought out. should have gotten the FX AMD chip.. why oh why did i
leave AMD for Intel!

i think this should be the same for games as not many programs are written
for dual processors..... so i'd be kind of effectivley using 2GHz of my 4
Ghz
prescott


ANy comments welcome!

Hyperthreading isn't the same as 2 processors, because it can't be doing the
same thing twice. But it can do different things. Lousy explanation, but
it's the best I can do right now. And it doesn't split the processor speed
into two pieces, either.

Hyperthreading does speed up certain things, if the application can handle
it, and it speeds up multiple processes, as long as they aren't using the
same CPU instruction. So, for example, if you're running an antivirus scan
at the same time you're doing other things on the computer, you won't get
the lag because the AV process and your other process are using different
CPU instructions.

But if you're doing ONE thing with the computer, you aren't going to notice
any difference, unless the program itself knows to split its own processes.

Same thing with dual processors, except that they can do two of the same
thing at the same time. (Grammatically, that sucked, but you get the idea).
If a single application isn't built to be aware of 2 processors, it will
only use one. In that case, the advantage is still that you can have
something else running on the other processor.

Nowadays, people usually are running multiple apps, even if they aren't
aware of it, what with virus monitoring, firewall, messaging programs etc.
So in theory, the things you want to run should run smoother because the
background apps can be using their own bit of the processor and not
time-slicing with the apps you're running interactively.

Whether you notice any speed difference or not depends on what you're
running. I've done tests, and it's not smoke and mirrors, but it's also not
nearly the same as a dual processor setup.

 

[Leythos]

Hey i wanted to know if anyone out there has noticed much difference with
hyperthreading on or off?

i mean xp pro is designed for 2 processors thats great but HT surely doesnt
split the cache in half so while 1 "processor" is being hammered the other
seems to have no or little load so to me i think HT is a big white elephant
Intel brought out. should have gotten the FX AMD chip.. why oh why did i
leave AMD for Intel!

i think this should be the same for games as not many programs are written
for dual processors..... so i'd be kind of effectivley using 2GHz of my 4 Ghz
prescott

Depending on what I'm doing I see about 30% improvement in FEEL and use
than when running the same thing on the same speed on a non-HT system.

I'm not your normal user, I run SQL Server on my system, have Windows
2003 server installed on it, and also run Exchange 2003 on it.

 

[Admiral Q]

A lot depends on how the program wrote the program - many programs used by
the "General Public" have not be refitted to use Hyperthreading - i.e. more
than one processor simultaneously. At present only your high grade
software, such as CAD, engineering or mathematical applications are geared
towards more than one processor on a Workstation - much less you day-to-day
role playing game being written to handle hyperthreading.
Jump to your AMD processor, won't make much difference - if the software
wasn't designed to take advantage of it, it won't do much good. Corporate
America wants the biggest bang for the smallest buck, writing a rootem
tootem role playing game to run on a single processor system is that ticket,
cause if it runs on a single processor, it'll run on a hyperthreading system
or a multiprocessor system. And it cuts into the profits to write 3
versions of the same software, when the later runs on all 3.

 

[Plato]

Hey i wanted to know if anyone out there has noticed much difference with
hyperthreading on or off?

Depends on the app.

 

[filmore]

Hey i wanted to know if anyone out there has noticed much difference
with hyperthreading on or off?

I have it on, out of the box with a new PC from TigerDirect. It's a
Systemax with a p4 3.4GHz under XP Pro SP2.

Firefox 1.0, Acrobat 6.0, SpyBot S&D all suffer from bugs relating to
hyperthreading -- apart from SpyBot they're annoying "freeze" bugs,
where the app reports "not responding" for a few seconds and returns to
normal (until the next time it freezes). A search in the Firefox and
Spybot forums will confirm this.

I'd like to know if these problems are due to programmer ignorance, or
are the XP drivers (software support for hyperthreading) still
unstable. If hyperthreading technology requires apps to be written
correctly -- Intel sells a tool to programmers called Thread Checker --
then I'd say that the future for this technology isn't too great.

My reading about the potential gain is that you can get up to 30%
improvement, according to some benchmarks. Google is your friend.

NT had a way to decide whether or not an app used one or more CPUs
(http://www.jsiinc.com/SUBH/TIP3500/rh3542.htm), but XP doesn't have
this. Once Firefox is running, I can switch it's affinity (via task
manager, right-click on firefox.exe process) to one CPU and I won't
have freezing problems with it. You just can't do this permanently
(that I know of).

My conclusion: unless you can know for sure that some CPU intensive app
will get the potential improvement, then hyperthreading isn't worth it.
The headaches caused by poorly threaded apps will lose you time! I've
already spent more time on this than I'll ever get out of the
theoretical hyperthreading performance!