Is a multiple processor/CPU's speed (combined/total) in the thousands of Ghz or ten's of thousands?

[4thcoming]

CPU's that have multiple processors in them, like AMD's 6 (or 8 core) chipset or Intel's i5 or i7, if each processor/CPU is between 3.4Ghz and 4.0Ghz, then would the combined total of speed be in the thousands still or tens of thousands?

(For example: 4 CPU's/processors that are each 3.4Ghz, would they be more like 12,000 Ghz combined and if so why don't companies list it like that?)

 

[Moonsfang]

Not every process however can be divided evenly amongst all the cores. Some things can be split up and some cant. You have handles, threads, and processes. For instance if you open up a game you will generally see only one or two processes in the task manager, and you will see multiple threads and handles. Multi core CPUs are just more efficient when running multiple things at once and can help reduce loads by giving different processes to different cores. Then there is scaling.. http://www.extremetech.com/computing/116561-the-death-of-cpu-scaling-from-one-core-to-many-and-why-were-still-stuck/2

 

[bigpinkdragon286]

Companies don't list processor speed as a combined total of cores multiplied by core speed as it would be a very misleading thing to do. As Moonsfang said, programs do not get divided evenly among all of the processing cores found on a CPU, plus there is arbitration overhead when using multiple cores in a single application, so you will never get perfect scaling. It is enough to know core count, frequency, and have a relative idea of IPC (instructions per cycle) to have an understanding of how a processor will perform. We wouldn't be helped by manufacturers adding more useless metrics to their parts to further confuse consumers. 🙂

 

[Moonsfang]

Companies don't list processor speed as a combined total of cores multiplied by core speed as it would be a very misleading thing to do. As Moonsfang said, programs do not get divided evenly among all of the processing cores found on a CPU, plus there is arbitration overhead when using multiple cores in a single application, so you will never get perfect scaling. It is enough to know core count, frequency, and have a relative idea of IPC (instructions per cycle) to have an understanding of how a processor will perform. We wouldn't be helped by manufacturers adding more useless metrics to their parts to further confuse consumers. 🙂

As if it isn't already confusing enough for the average person. Even people that know what there talking about can get confused when you have so many different things to go by as it is. Doesn't help that the actual processor name are all so similar.. It's probably the reason that all the microarchitectures have their distinct code names such as Haswell, Ivy Bridge, ect.. It would probably be a lot more simple with few numbers and more distinct features. I'm sure there is a lot of people that get sick of doing their own research because of it and then turn to ask other people or just make a lazy uniformed decision.

 

[hunter315]

The frequency is the same, each core has a signal going to it that alternates four billion times a second for a 4GHz processor, just because you have 4 cores doesn't mean you now magically formed a signal that alternates 16 billion times a second, they are all feeding from the same clock signal.


Now, your MIPS and FLOPS have increased, those are the actual metrics of computing performance, for a perfectly parallel task 4 cores means you can perform four times as many instructions per clock cycle but each clock cycle still happens in 1 four billionth of a second(aka 4GHz)

Avoid confusing clock speed with how much a CPU can do, as soon as you cross between micro architectures the clock speed is a meaningless number. Good example of this is how 3.3GHz Core2Quads were notably outperformed by the 2.66GHz i7 920 when it first launched, the core2's had a 25% advantage in clock speed, but the i7 architecture was about 30% more efficient per clock so it easily closed the gap.

 

[8350rocks]

The frequency is the same, each core has a signal going to it that alternates four billion times a second for a 4GHz processor, just because you have 4 cores doesn't mean you now magically formed a signal that alternates 16 billion times a second, they are all feeding from the same clock signal.


Now, your MIPS and FLOPS have increased, those are the actual metrics of computing performance, for a perfectly parallel task 4 cores means you can perform four times as many instructions per clock cycle but each clock cycle still happens in 1 four billionth of a second(aka 4GHz)

Avoid confusing clock speed with how much a CPU can do, as soon as you cross between micro architectures the clock speed is a meaningless number. Good example of this is how 3.3GHz Core2Quads were notably outperformed by the 2.66GHz i7 920 when it first launched, the core2's had a 25% advantage in clock speed, but the i7 architecture was about 30% more efficient per clock so it easily closed the gap.

That's a good layman's summation.

Look at it like this...

Within the same manufacturer, and architecture generation, clockspeed is a relative comparison of speed of the processor.

For example, one can compare the FX 6300 and FX 8350, the 6300 runs @ 3.5 GHz and the 8350 @ 4.0 GHz, the 8350 will be notably faster.

Now, if you compare the FX 6200 (bulldozer) to the 6300 (piledriver), the 6200 runs @ 3.9 GHz, giving it a clockspeed advantage. However, the 6300 is 15% more efficient processing instructions. This means the 11.4% advantage in clockspeed is actually overcome by the greater efficiency in the 6300. The 6300 will be faster at lower clockspeeds.

You can do the same with Intel as well.

Use clockspeed as a reference point in the same generation of the same architecture, as a relative measure of performance

 

[logainofhades]

I heard a Best Buy sales guy trying to sell a laptop to this old couple and he combined the clock speed among all 4 cores. I think he saw the look on my face as he quickly moved away. :lol: I am amazed that I haven't been kicked out of a Best Buy yet. Far too many don't have the slightest clue as to what they are attempting to sell.

 

[Moonsfang]

I heard a Best Buy sales guy trying to sell a laptop to this old couple and he combined the clock speed among all 4 cores. I think he saw the look on my face as he quickly moved away. :lol: I am amazed that I haven't been kicked out of a Best Buy yet. Far too many don't have the slightest clue as to what they are attempting to sell.

Whenever I'm in a best buy and see them doing that I always correct them. Sometimes management in best buys know what they are talking about. But thats typically only if they're an ethusiast or gamer. They hire people that are good salesmen and nothing more. Your better to attempt to fix your own pc even if you have no idea what your doing than take it to them so they can make more non exsistent problems for you to pay them for.

 

[logainofhades]

Wouldn't take my stuff to Geek Squad either. Hate to think how many times I have had to fix their so called repairs.

 

[Moonsfang]

Best Buy is on a train straight down. And rightfully so...

 

[bigpinkdragon286]

Well, look at it from their perspective? How are you supposed to get good quality IT workers when you pay close to minimum wage? 😛 On the other hand, last time my nephew went there, he was told his hard drive was dying when the actual problem was his power supply.

 

[Moonsfang]

Well, look at it from their perspective? How are you supposed to get good quality IT workers when you pay close to minimum wage? 😛 On the other hand, last time my nephew went there, he was told his hard drive was dying when the actual problem was his power supply.

Yeah true.. Although some of they're employees make a lot more than they should.. I've seen some Geek Squad members get $12/hr.. Best Buy intentionally trains morons though and make them into lying salesmen. You could have taken it in there with an unplugged SATA cable and they may have said the same thing.

 

[bigpinkdragon286]

True, except I wouldn't have taken it there. Pretty sure he learned his lesson. 🙂 I fixed it for him and he got to keep, and still uses the hard drive, as it's perfectly fine.

 

[logainofhades]

Well, look at it from their perspective? How are you supposed to get good quality IT workers when you pay close to minimum wage? 😛 On the other hand, last time my nephew went there, he was told his hard drive was dying when the actual problem was his power supply.

You can hire high school and college kids that are competent even at those wages. BB just hires idiots.

 

[bigpinkdragon286]

Probably because the "competent" ones don't want to work there. 🙂 I think part of that comes from it being a job, rather than a career, and competent individuals are usually a bit more forward thinking.