Multi CPUs

[xxBAFOWxx]

My mobo only has one CPU slot, with a CPu in it of course, but when I open device manager i go to...

Computer - ACPI Multi processor PC (but its not a multi processor PC)

Processors - Intel Pentium 4 CPU 3.00Ghz
- Intel Pentium 4 CPU 3.00Ghz (same thing)

why is it saying I have 2? how can I change this?

edit: this bothers me because at start up it says, cpu is unworkable or has been changed. and it stops the computer, I have to press F1 for it to skip it and continue. I think the multi process thing may be causing this.

[hobey19]

when you have a hyperthreaded pc and HT is enabled, i believe it shows up as two diff. processors in Device manager. someone correct me if i am wrong, but i remember seeing something about that here a little while ago

craig

[bailey]

in a way it is.
if you go to system performance you will see that there is two cpu shown there.

the reason for that is the fast that you are useing dual data rate memory which results to doubleing the cpu processing power.

this is how you know that everything is working good, also how you get the 800mhz data bus rate.
I am not useing the correct terms for this magic but it should give you a idea of what is happening.

[xxBAFOWxx]

oh Ok I see, but one more thing

does this hyper threading thing REALLY double the power, I mean is it really noticeable to the human uh.. eye?

[Mesaeus]

IIRC, about 10-15% speed increase about maximum. Some applications can even run SLOWER thanks to ht. I'd leave it on, but don't expect any miracles.

[Alaron]

It's not really doubling the power in the normal sense of "Double". A Hyperthreaded P4 at 3GHZ does not give you 6Ghz of performance. The cpu instead can now process 2 things at once (in certain applications). All cpus are designed to process one thing at a time. HT allows 2 things at a time. In the applications that support HT, which are few, you see great gains, but if you aren't using any of these, HT makes no difference.

[xxBAFOWxx]

aah OK, that makes sense, thanx

[Yuanji]

just wondering, what Apps availible right now support HT?

[thefultonhow]

Originally Posted by Yuanji just wondering, what Apps availible right now support HT?

Any app that is multithreaded. But XP supports allocating apps to different logical processors, so if you're running two apps you will get the same performance boost.

[Yuanji]

Originally Posted by thefultonhow Any app that is multithreaded. But XP supports allocating apps to different logical processors, so if you're running two apps you will get the same performance boost.

wondering what multithread apps there r now

[thefultonhow]

Originally Posted by Yuanji wondering what multithread apps there r now

Photoshop is one, and XP itself is another. But really most of the performance benefit comes from multitasking.

[Yuanji]

Originally Posted by thefultonhow Photoshop is one, and XP itself is another. But really most of the performance benefit comes from multitasking.

thx this is a big plus then for me cuz i like to turn on music and stuff when i'm playing games

[MrAustin]

Most all applications now a days support multiple thread processing. If you do some Java and/or VB programming, you learn quickly that to run a program efficiently, you need to know how to handle threads.

Normally a program handles a single thread at a time, pauses that thread so another can do its thing, then starts the first one again. On and on until it finishes (which it usually never does). With HT, the program is allowed by the processor to run more than one thread at any given time.

[RedKangaroo]

From what I've heard, Windows XP runs about 30% faster with HT enabled... which is quite a nice boost. The only annoying part of it is if you open task manager, it usually only says 50% CPU usage when you're using 100% in reality. Try running Prime95 and you'll see this. If you're running anything else at the same time, the percentage will rise above 50% though. But in reality, the other program will be stealing some CPU usage from Prime95 even though it says it's utilizing more CPU power.

[Redfallon]

Just wanted to post a couple things here.

Bailey: The two "processors" are a result of the hyperthreading capabilities. Dual channel, double data rate RAM only increases the memory bandwidth available to the processor. This keeps the information coming to allow the processor to run keep running two threads at once.

Redkangaroo: If you're only running 1 instance of prime95, then you really aren't using 100% of a ht processors power. When you run another "process" xp will run it in a seperate thread, which, you're correct, will "steal" a little of prime's processor time, but not as much as on a non-ht cpu, where prime, having a low priority, will take a back seat to any other process. If you run two instances of prime95 you will get 100% cpu usage, this is the only way to truly stress test a ht processor, and it will heat up more/faster than running 1 instance.

xxBAFOWxx: Your XP should display 2 processors if you have HT enabled. You *can* turn it off, but this isn't causing your problem at boot up. Is your PC overclocked? Is everything set correctly in the BIOS? If not OC'd, and set correctly, you could have a weak/dying CMOS battery which is causing your BIOS to reset and at boot up, pressing F1 might be to restore "stock" settings. The CMOS battery is no more than a watch battery that's easily replaced. How old is the build? Has the PC always done this? It's possible even a new(er) mobo could have a dead/bad battery. The only other thing I could think it may be is a cpu and/or motherboard problem.