Does CotN fully run in HT (HyperThreading?)

[Jacquou Le]

I'm using P4 3.0 with HT (socket 478.)

It's weird that CotN runs much slower when I enable HT in BIOS. I check in Task Management, CotN only takes up to 50% of CPU usage. But when I reboot the system and disable HT, CotN runs like a dream :confused: and it takes range 70% - 99% of CPU usage.

Any idea?

[Keith]

Mine is P4 3Ghz HT Intel. No problems here. Runs the same for me either way.

[Keith]

Image 1 below is my system at the desktop running Paint Shop Pro, Azureus, and the BOINC Seti@Home apps. BOINC/Seti run 100% of the time, all the time. Azureus is usually running 24/7 when I'm using it. You can see the CPU % is pegged at 100.I have Seti setup to process data using both virtual CPUs that hyperthreading provides.

Image 2 is with all the above running except for BOINC/Seti. The CPU usage drops way back.

Image 3 is with all the above running, plus Children of the Nile with a save game loaded.

Image 4 is with everything running as in image 3 except for BOINC/Seti.

[Manni]

Mine is P4 3.2 Ghz HT, no problems whatsoever.

Have a look for a newer bios......might do a difference. :)

[wodinoneeye]

Image 1 below is my system at the desktop running Paint Shop Pro, Azureus, and the BOINC Seti@Home apps. BOINC/Seti run 100% of the time, all the time. Azureus is usually running 24/7 when I'm using it. You can see the CPU % is pegged at 100.I have Seti setup to process data using both virtual CPUs that hyperthreading provides.

Image 2 is with all the above running except for BOINC/Seti. The CPU usage drops way back.

Image 3 is with all the above running, plus Children of the Nile with a save game loaded.

Image 4 is with everything running as in image 3 except for BOINC/Seti.



If you have a CPU with HyperThreading, shouldnt your TaskManager Performance display show 2 CPU traces ?????

[Keith]

No, because the task manager only shows the physical CPU not the virtual CPUs that hyperthreading use.

The hardware device manager shows two CPUs under the Processor setting when hyperthreading is enabled.

[mouse]

3.4ghz socket 478 Northwoods processor with HT enabled and CotN runs just great with HT enabled:D

[King Faticus]

forgive my ignorance, but what exactly is "hyperthreading"

[Manni]

http://arstechnica.com/articles/paedia/cpu/hyperthreading.ars

[King Faticus]

http://arstechnica.com/articles/paedia/cpu/hyperthreading.ars
Really really long:( But I have an idea of what they are and even how they work now ty:)

[Keith]

The idea is to let you run simultaneous applications without taking a performance hit on either one. It allows one CPU to virutally function as two CPUs, each handling seperate compuations. So you could be editing a movie and working ona Word document at the same time without either apps noticibly slowing down.

The newest CPU have dual cores (http://www.intel.com/technology/magazine/computing/dual-core-0505.pdf). They actually have two execution cores in one chip and they have parallel processing paths, where has hyperthreading has one path shared by both virual CPUs.

[Keith]

So you mean if I were playing cotn and browsing the internet and using paint and being in word and notepad and checking my email without any slowdown on the programs I would be hyperthreading?

No, if you had a normal single core CPU without HT technology, you'd be lucky.

It's only hyperthreading when the single CPU with HT technology is virtually split into two execution cores and each one is running seperate apps. If it disable HT in my BIOS, my CPU behaves just like any other single core CPU. The Seti@Home program I am running full time in the background on my system, is using both execution cores and processing two data fragments at the same time instead of just one.

Not all open apps require processing constantly. Now, if you were simulatenously compling a movie file while doing some heavy number crunching on a single core CPU you'd see a hit in performance in both apps.

[Manni]

Have a look into your device-manager

[Keith]

Also, if you have it the INTEL logo will have a small "H T" on it.

And, if you have it but don't have it enabled, you enable it from the BIOS menu. I forget the name of the BIOS menu section its in and the setting name. I'd have to reboot to check and I don't feel like that right now. Manni, might know.

[Keith]

If you have Windows XP. Right click on the My Computer icon on your desktop. Select Properties. Click on the Hardware tab. Click on the Device Manager button. Then find the Processor section on the Device Manager list and expand it.

To get to the BIOS menu you have to press the F2 or F8 button on your keyboard immediately after it beeps when you restart it. The setting is there in the BIOS menu IF you have hyperthreading capabitlity.

Be very careful when in the BIOS menu. One wrong click there and you can disable your machine. So don't change anything unless you know what it is.

If you find it and you have it enabled, you have to SAVE & EXIT to make the change when leavin the BIOS menu.

[wodinoneeye]

No, if you had a normal single core CPU without HT technology, you'd be lucky.

It's only hyperthreading when the single CPU with HT technology is virtually split into two execution cores and each one is running seperate apps. If it disable HT in my BIOS, my CPU behaves just like any other single core CPU. The Seti@Home program I am running full time in the background on my system, is using both execution cores and processing two data fragments at the same time instead of just one.

Not all open apps require processing constantly. Now, if you were simulatenously compling a movie file while doing some heavy number crunching on a single core CPU you'd see a hit in performance in both apps.




A single core with Hyperthreading does not have 2 cpu execution cores. Its more like it has 2 sets of registers (each one running a different thread) that can quickly be switched bewteen (switching threads is called a 'context switch' and without HT is a costly operation as all the registers and states have to be saved and the new threads registers/states all have to be loaded). The HT logic may also allow scheduling use of functional subblocks like Adders, Floating point unit, memory manager, etc.. between 2 processes and one can be busy loading its registers while the other is running normally or when a cache miss happens, the other process which already has its data can run while the other waits..

[Keith]

Right, I had just read the bit about the dual core CPUs and had that on my mind. A single core HT CPU has two virtual processors.

[Manni]

what language is that picture in and what is that a screenshot of?
The language is German and the shot says DEVICE MANAGER :)

By the way............why don`t you use INTELS Hyper-Threading Technology Test Utility

you`ll find it here: http://downloadfinder.intel.com/scripts-df-external/Product_Filter.aspx?ProductID=1687

[Jacquou Le]

With my personal measurments, I see that when HT enabled, the CPU tempature increases 1° C - 3° C.

There's some apps which don't run properly (in my system) when HT ON as Nero (just at 50% of CPU usage when re-encoding movies); CotN (as mentioned above); GIMP (completely not run); Folding @ Home of Stanford Uni. (just 50%); ATI Multimedia Center ([not quite sure] if capturing movies from Composite-In with real-time encoding.)

Actually, HT tech is good, for me, but it's also a turn-off when I use above apps frequently, especially with GIMP and CotN :(.

[Manni]

Very interesting Jacquou Le !!

I simply forgot about my HT and never change it in BIOS.
But I DO have noticed when encoding a DVD the CPU is totally busy and temperature goes up to 60 degrees, as I can see on my front-degree-gauge.

Games go up to 40 or some to 50 degrees centigrad, depends which.
Virus or Spyware-scans are also a burden and are better be left alone while searching.

[Keith]

Um, I am sorry for my ignorance, but what does all this gibberish meen?

The test results indicates that your system does not meet the requirements for Intel
(R) Pentium(R) 4 processor with HT Technology; therefore, one or more of the key
components for the technology are or may be missing or not functional/turned on. Intel
suggests you contact your PC system manufacturer or reseller to resolve the problem. To learn
more information on the test results, please select "Technical Tips" from below.
Intel strives to educate and ensure that system integrators have the knowledge and correct
tools to properly understand the technologies and their requirements. However, if you
believe there is an issue with an integrator and/or manufacturer using and applying the Intel(R)
Pentium(R) 4 processor with HT Technology logo label inappropriately to their products, please feel
free to let us know by selecting "Notify Intel" below where you will be asked a series of questions about
your system, integrator and/or manufacturer. All data collected will be handled as anonymous and confidential.

P. S. You know German, Manni? Cool!

Manni is German. ;)

Looks like your system either doesn't have HT and is mislabled if it is labeled as having HT or its broken and not working.