How does xp use dual core?
Discussion
Just started using a dual core P4 machine at work, well I'm presuming it's dual core - two processors show up in windows.
However when I'm doing intensive work it can be seen in task manager the process is only taking up 50% of the processing ability. While this is great for multi-tasking (and surfing PH while number-crunching!) i'd prefer if all the processing power is used for the intensive task!
Is there settings I can change to take advantage of the power available or is this simply how dual core works, and benefit is seen in multi-tasking rather than outright grunt?
However when I'm doing intensive work it can be seen in task manager the process is only taking up 50% of the processing ability. While this is great for multi-tasking (and surfing PH while number-crunching!) i'd prefer if all the processing power is used for the intensive task!
Is there settings I can change to take advantage of the power available or is this simply how dual core works, and benefit is seen in multi-tasking rather than outright grunt?
The benefit is in multi tasking; not outright power.
There *may* be a switch in your BIOS that disables the hyper threading / dual core capability and you *may* notice a slight increase in computing power *if* you do this.
Note caveats! I've tried it on 2 different PCs and it hardly made any difference.
HTH,
Greg
There *may* be a switch in your BIOS that disables the hyper threading / dual core capability and you *may* notice a slight increase in computing power *if* you do this.
Note caveats! I've tried it on 2 different PCs and it hardly made any difference.
HTH,
Greg
XP only allocates cores on a per-process level, so if only one process is going flat out only one core will be maxed, hence 50% total usage.
BTW old stle P4's with hyperthreading also show up as two cores in task manager. In some cases w. multiple hyperthreaded processors some apps show better performance with hyperthreading turned off, (but generally its best left on).
BTW old stle P4's with hyperthreading also show up as two cores in task manager. In some cases w. multiple hyperthreaded processors some apps show better performance with hyperthreading turned off, (but generally its best left on).
Cheers Greg/Aldi
It could well just be hyperthreading rather than dual core, given the age - it's definitely not a core 2 duo.
Sounds like there is no way of using "full power" as it were, I don't think I'll go messing with the bios for the sake of small increases! I tried getting around it by opening two copies of the software, but the licensing seems to clever to le me do that. Still, at least PH runs at full speed while I'm running simulations!
I'm amazed how little I understand about todays computers though - I remember upgrading our DX2/66 at home to an AMD K7 and understanding everything at that time, now just choosing a graphics card seems more complicated that specing and carrying out that upgrade!
It could well just be hyperthreading rather than dual core, given the age - it's definitely not a core 2 duo.
Sounds like there is no way of using "full power" as it were, I don't think I'll go messing with the bios for the sake of small increases! I tried getting around it by opening two copies of the software, but the licensing seems to clever to le me do that. Still, at least PH runs at full speed while I'm running simulations!
I'm amazed how little I understand about todays computers though - I remember upgrading our DX2/66 at home to an AMD K7 and understanding everything at that time, now just choosing a graphics card seems more complicated that specing and carrying out that upgrade!
Know how you feel.
I was excited about learning we had a 286 machine and I could get games for it, then reading I needed a all singing 386 to play the latest and getting that and well the rest is history.
Now a bg green alien has taken over my house, my graphics card has more ummph than my compt did 4 years ago, the processor speed is into mega hz rather than hundreds, disc space is bigenough to store the worlds library on and now they have duel and quad core things as well as SLI cards and cross fire, DVD recorders, card readers, Ram mem larger than my house, you name it it does it.
It blows the mind how fast things have moved. I find computer mags about hardware developments more interesting than car mags now TBH.
I was excited about learning we had a 286 machine and I could get games for it, then reading I needed a all singing 386 to play the latest and getting that and well the rest is history.
Now a bg green alien has taken over my house, my graphics card has more ummph than my compt did 4 years ago, the processor speed is into mega hz rather than hundreds, disc space is bigenough to store the worlds library on and now they have duel and quad core things as well as SLI cards and cross fire, DVD recorders, card readers, Ram mem larger than my house, you name it it does it.
It blows the mind how fast things have moved. I find computer mags about hardware developments more interesting than car mags now TBH.
egomeister said:
Another random question!
The machine has a gig of ram, if the processor is effectively split into two does the same happen with the memory? Ie, if the process can only address half of the total processing power can it also only access half the memory (eg 512mb)?
The machine has a gig of ram, if the processor is effectively split into two does the same happen with the memory? Ie, if the process can only address half of the total processing power can it also only access half the memory (eg 512mb)?
No, there's only one pool of memory for all processes irrespective of what core they're running on.
GregE240 said:
Plotloss said:
Theres a specific multi-processor version of XP
Eh?Ditto, eh?
The OS will assign a processing resource to a thread. If the application is not multithreaded, it'll max out one of the CPUs, and the other will be idle. This isn't a bad thing, as it means you can do useful work rather than rely on Windows rather non-idea resource sharing.....
I have a multi xeon server in the lab, and one of the apps frequently redlines a CPU for *hours* at a time.
aldi said:
XP only allocates cores on a per-process level, so if only one process is going flat out only one core will be maxed, hence 50% total usage.
Just incase anybody needs a picture to get that I tend to describe each process as a salesman and each processor/core as a car. A salesman can only drive one car at a time. If you have two salesmen then they can have a car each. If you have more they'll have to queue to use one of the cars.
(it gets more advanced when dealing with processor affinity)
A salesman can get out and use the other car if it's free, but that means taking his stuff out of one car and putting it in the next which wastes time, so he'd prefer to go back to the car he used last.
Mr E said:
I have a multi xeon server in the lab, and one of the apps frequently redlines a CPU for *hours* at a time.
Is it the app using all the proc or is the app doing so much disk/memory work that windows wipes out the other proc? (Not that it's a problem so long as the job finishes when you want, just curious.)
Mr E said:
I have a multi xeon server in the lab, and one of the apps frequently redlines a CPU for *hours* at a time.
You may laugh at this, my previous company spent £x000's on a Quad xeon XXGB's ram etc server to run an extremely processor/memory hungry app, found out about 3months later it wouldn't multithread!
munter said:
Mr E said:
I have a multi xeon server in the lab, and one of the apps frequently redlines a CPU for *hours* at a time.
Is it the app using all the proc or is the app doing so much disk/memory work that windows wipes out the other proc? (Not that it's a problem so long as the job finishes when you want, just curious.)
No, pure CPU (eats a fair bit of memory up too, but we have enough of that). The machine is quite usable on the other CPUs and most of the time nobody notices.
annodomini2 said:
Mr E said:
I have a multi xeon server in the lab, and one of the apps frequently redlines a CPU for *hours* at a time.
You may laugh at this, my previous company spent £x000's on a Quad xeon XXGB's ram etc server to run an extremely processor/memory hungry app, found out about 3months later it wouldn't multithread!
Nope, I'd suggest that was pretty normal for an awful lot of companies.
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