Computer Upgrade Time (?)

[Mechcommander]

[sponge]

[James S]

[damian]

[James S]

What do you mean? There are dual processor computers. There have been ever since the first pentium came out. You can put two processors in them to get double the clock speed. Each processor works in tandum. Actually it's the ONLY way that you could truly "multi-task" until Intel came up with HT to run on one processor.

You see, a processor can only do one thing at a time. If you've got 5 IE windows open and AIM then the processor first processes commands from Windows, then it goes to one of the IE Windows, then the next, then the next, and finally processes commands from AIM, then back to windows. Nothing on the computer happens at the same time. That's impossible, unless you have two processors or HT in the a Xeon or the latest Pentium 4 processors.

These motherboards just have two places for CPUs to go. Just like how you have more than one slot for RAM or PCI cards that all can work seperately. Well two slots for CPUs and each can processes stuff seperately and thus speed up the computer because it can do two things at once without slowing down.

So if I had two Pentium4 3.06GHz HT processors in my computer then they'd actually be able to process four events simultaneously for a combined speed (theoretically) of 12.24GHz. This isn't actually true, however, and you won't see the performance increase over 3.06GHz, but you'll be able to do multiple things all at that speed. So it's very similar to having a single line 12.24GHz processor, except that it won't run a SINGLE program faster (unless specifically optimized to use dual processors in tandum). It will just run FOUR programs all without slowdown.

[damian]

Having two processors is NOT doubling the clock frequency... it's having two processors. It doesn't necessarily mean that performance doubles, either. It depeneds very much on what program is running on them and how well it was written to handle them.

[sponge]

No OS until NT4+ made use of SMP, your 2nd processor would go largely unused. HT is still new technology, even though it's been in processors for a while, it's only now being used, so of course large improvements will be made. Windows 95 would never use the 2nd processor, and even in 2K you have to manually specify which application you want to use which processor. So if you have 2 1.5ghz processors, your not going to have the equivlant of 1 3ghz processor, which is what your inferring.

Moose, just because your cranky about school doesn't mean you can bitch everyone out when their opinion is slightly different.

[esw]

What's HT?

[(TSC)Bender]

Hyper-threading I believe. Search for it, might be an interesting read...

[sponge]

Yes, HyperThreading. Basically splits your processor into 2 processors, all OSes should see it as having 2 P4 3GHz processors in your PC.

[(TSC)Bender]

Shouldn't it be two P4 1.5 Ghz processors?

[sponge]

No, the BIOS recognizes it as 2 P4 3GHz processors.

[James S]

I didn't say it increases clock frequency. I said it's the same as running 4 programs at the same time on a processor that's 4 times as fast. Each program can be run without slowdown because each program is processed at the same time in different parts of the processor.

And SMP support is almost a null factor, now a days, unless you haven't upgraded your OS in two years and in that case you shouldn't be getting a 3GHz P4 for your computer with an old OS. Read the AnandTech.com article on the 3GHz P4. Very interesting, and the benchmarks are great. It still doesn't hold up to an equal frequency Athlon, but Athlon doesn't even make a 3000+ processor yet, let alone one with dual thread support that increases performance by 40%. Plus Pentiums are much safer. If a P4 overheats then it shuts down. If an Athlon overheats then it burns up and damages your entire computer.

[sponge]

Even on WinNT4+, most programs won't use SMP. You can tell Windows to use a processor for any program you want, but that preference isn't saved, nor will it loadbalance automagically. Quake3 had SMP support, until someone broke it, so DoomIII will have it. Not sure about the other games.

[Mechcommander]