Hyperthreading in upcoming P4's

[Duvie]

With the talk of the HT being enable in the release of the 3.06 p4 plus the fact that INtel has rumored changed the HT as it was in the xeon so talk about decreasing performance in a majority of apps may not be as much of a reality, I was wondering a few things...

Since HT is basically already there in the current p4's and just not enabled it makes me wonder if INtel may in fact with the newer stepping to be released and with the 3.06ghz p4 if they will go ahead and enable the HT at lower levels as well??? It makes you wonder though. It is possible but may make alot of ppl angry who may have purchased upper c1 stepping processors recently.

Would be nice to think about since some of the lower chips are more likely my next upgrade...I may not upgrade to a 3.06ghz cpu for 6months to a year especially if 1.8's can run possible 3ghz plus with upcoming c1 and d1 steppings. Plus if Granite Bay dual channel ddr modes only have 1:1 ratio lower multiplier chips with high fsbs will be the real winners...

 

[THUGSROOK]

HT need be coded into the application to work ~ so we are still talking "future" here.

also the need for "3 phase voltage regulation" seems to be a needed reality for chips running beyond 3ghz on default voltage. adding voltage (IE overclockers) is going to make it even worse for the moboard ~ the board will fry tryin to handle it. (of course this will take some time to prove)

DC DDR is "supposed" to debut in 333DDR form ~ not sure what thet means for ratios tho.
overclockers running 160+fsb might have a serious advantage here.

i agree this going to be interesting in the next few months

 

[Duvie]

agreed on the software answer...yet I hear winxp is already setup for it and INtel seemd to debut some testing of programs like microsoft office and media encoders which already seemed to be taking the advantge of it...Those 2 would be welcomed for me as well....

I like the notion of capturing and encoding at full speed while be able to do many other apps with no degradation to those apps or slowing down the encoding through use of priority settings....


There defnitely will be some time to catch up fully and I definitely don't see ever paying much more then 200 dollars for a cpu...God say AMD!!!! God bless AMD for that!!!

 

[Bobbyeyes]

this is a nice read w/ nice links about the topic
here
thugs quote:
HT need be coded into the application to work ~ so we are still talking "future" here

indeed we are

and Duvie
AMD is down again today, and is hovering at slightly above $3/share...oh boy!

 

[Duvie]

very little actual info on HT though!!! I would recommend hitting the thread that was circulating 2 days ago in here that was highly more technical....I think many programs including winxp home edition are ready to see some advantage now though may not be the optimal form yet....

Just a thought, anybody else have a thought??

 

[mechBgon]

I thought HT was not something that needed to be coded for. If the hardware side of things is set up, I thought the OS would see the "virtual" second CPU and use it just as it uses the second CPU on a real SMP system (although perhaps not to the same extent). And if you recall, Intel's demos showed that type of usage, right? They ran apps side-by-side on multi-monitor systems running with HT on, and with HT off, to demonstrate that it can do two things at a time more smoothly. Or am I just ""?

edit: as I recall, some of the demo programs were current games and such, which I doubt were rewritten just to make HT demos out of.

 

[JeremiahTheGreat]

That's right, it should prove to be more 'smooth' when running two or more apps at the same time. But seriously, who is going to be rendering in photoshop while playing Doom III ?

 

[mechBgon]

Originally posted by: Duvie
I think many programs including winxp home edition are ready to see some advantage now though may not be the optimal form yet....

WinXP Home is not a dual-processor-aware operating system, so now maybe I am even more "" or else Microsoft has been telling whoppers for a while. OTOH, there is this article at the Inquirer quoting Microsoft as saying HT is supported in WinXP Home. Yes, now I'm definitely .

 

[CrazySaint]

Originally posted by: mechBgon
I thought HT was not something that needed to be coded for. If the hardware side of things is set up, I thought the OS would see the "virtual" second CPU and use it just as it uses the second CPU on a real SMP system (although perhaps not to the same extent). And if you recall, Intel's demos showed that type of usage, right? They ran apps side-by-side on multi-monitor systems running with HT on, and with HT off, to demonstrate that it can do two things at a time more smoothly. Or am I just ""?

edit: as I recall, some of the demo programs were current games and such, which I doubt were rewritten just to make HT demos out of.

My understanding is that while programs don't necessarily have to be coded specifically for hyperthreading, they do have to be coded for multithreading (the process that allows a program to simultaneously use two CPUs), so that applications that are already written to take advantage of multiprocessor systems will be able to take advantage of HT. Unfortunately, right now most apps that support multithreading are server apps, plus a few high end apps like 3DSMax. However, I believe that WinXP already supports multithreading, so that even if individual apps won't be able to take advantage of HT, it will speed up multitasking. Also, at the recent IDF Intel talked about something called "pseudo-hyperthreading" for non-multithreading apps, which basically launches a "helper thread" which 'guesses' what data the app will need next and feed it to the CPU so even non-multithreading apps will see a benefit. But this is all IIRC so I may be off on a few points.

 

[mechBgon]

One main cause of my is that WinXP Home is not capable of using two real CPUs in a real SMP system, which is one of WinXP Professional's claims to fame over WinXP Home. Now Microsoft appears to say that WinXP Home supports Hyperthreading, which would seem to have SMP support as a prerequisite since HT emulates SMP. Is there going to be a Microsoft patch that automagically makes XP Home into an SMP-capable operating system, or at least a HT-compatible one? (shrug)

Intel's demos seemed to focus not on multithreaded apps, but mutiple single-threaded apps. And Anand's findings, along with the others I've read, seemed to say that HT is at its best when the threads are not trying to do the same thing at the same time, which is where HT becomes a liability and decreases performance. So maybe two diverse tasks represent what HT is best at... yes, running Doom III while batch-rendering in Photoshop probably is diverse enough Anyway, I guess we'll see later this year, when the rubber meets the road.

 

[LastRide]

 

[CrazySaint]

Originally posted by: mechBgon
One main cause of my is that WinXP Home is not capable of using two real CPUs in a real SMP system, which is one of WinXP Professional's claims to fame over WinXP Home. Now Microsoft appears to say that WinXP Home supports Hyperthreading, which would seem to have SMP support as a prerequisite since HT emulates SMP. Is there going to be a Microsoft patch that automagically makes XP Home into an SMP-capable operating system, or at least a HT-compatible one? (shrug)

Hmm...dunno, now I'm , too

 

[mechBgon]

OT: CrazySaint, you look so fetching in that red-&-white label

<-- author of "Can 'O Worms" avatar

 

[CrazySaint]

Originally posted by: mechBgon
OT: CrazySaint, you look so fetching in that red-&-white label

LOL Why, thank you!

<-- author of "Can 'O Worms" avatar

haha, good job

 

[imgod2u]

Just to clarify. WinXP Home actually does use the same core as XP Pro. So multithreading support is there. However, the ability to support 2 physical processors is purposely disabled. XP, however, is able to tell the difference between physical processors (such as in the case of SMP) and logical processor (in the case of 1 CPU accepting multiple threads at once). You are limited to only the number of physical processors. You get all the logical processors you want for free. So while XP Home will not let you have 2 physical processors it will let you have 2 logical ones and balance multithreading across them accordingly. And again yes, HT will impact all multithreaded environments. The only case in which it wouldn't would be in OS's such as win95/98/ME in which multithreading is not supported and in NT based OS's that do not support ACPI (I think it was).