HT questions

[neilm]

I read somewhere that HT only works under XP, so me being a 2K user, I wouldn't benefit from the HT, just acts like a normal 3.0ghz P4 chip? Just wondering if I should wait or buy the 2.4b.
Also, is there any smaller sizes in the HT chips, like 2.5ghz or similar?

Thanks

 

[ChampionAtTufshop]

2k supports smp and therefore supports ht as well i believe

xp home does not
xp pro does

there are not any ht enabled cpus lower then 3.06 at the moment, there will be later on i believe because intel will produce lower mhz cpus with ht
im pretty sure i read that somewhere

 

[CrazySaint]

Actually, WinXP Home also supports HT, but WinXP Pro supports more CPUs than Home does.

 

[Yomicron]

Windows 2000 will see an HT chip as two physical CPUs instead of two logical ones, but it should work fine.

You run into problems if you are using the maximum number of CPUs before enabling HT, i.e. you're running 2000 pro with 2 HT Xeons, win2k will think you have 4 CPUs but will only let you use 2 of them (win2k pro only supports 2 CPUs), so there is no gain from having HT.

XP sees two logical cores, so it does not run in to problem in multiple processor configurations.

 

[Rand]

Originally posted by: neilm
I read somewhere that HT only works under XP, so me being a 2K user, I wouldn't benefit from the HT, just acts like a normal 3.0ghz P4 chip? Just wondering if I should wait or buy the 2.4b.
Also, is there any smaller sizes in the HT chips, like 2.5ghz or similar?

Thanks

Won2K will utilize HT... however it will recognize them as being two physical processors, so you will not be able to add another phyiscal processor....... which in your case is not a limit in any case as the P4 isnt multiprocessor capable.
You may experience lower performance then you would under XP however, as Win2K will see both as being 2 physical processors and hence won't be able to properly schedule the more active thread to the primary logical processor.

Personally I'd disable HT under Win2k, scheduling issues are more likely to cause a performance hit..... it will work if you wish though.


HT is enabled in the 3.06GHz P4, and the Xeon based P4's only at present. They do have plans to release lower clocked P4's with HT functionality enabled however.

 

[XBoxLPU]

How does Seti run with HT enabled ?

 

[Yomicron]

Originally posted by: XBoxLPU
How does Seti run with HT enabled ?

The data analysis for SETI@home isn't multithreded (at least for windows), Seti might run faster if you are rendering the graphics, but it would still run faster if the graphics are disabled.


from the SETI FAQ:

SETI@home uses 90% of the time on two CPUs. Why does it do this if it's not multithreaded?
One CPU is doing graphics and the other is doing data analysis (so actually it is multithreaded, in a limited way).

 

[XBoxLPU]

But the CL is not graphics

I am sure you could set Seti Driver to 2 processes, but i haven't seen anyone that has tried it with HT.

 

[neilm]

I'm buying my system early january, so I take it 2.4b would be best under win2K at the moment?