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Zwhaler

macrumors 604
Original poster
Jun 10, 2006
7,267
1,965
Ok, I didn't know where to post this, so I put it here because I knew a lot of people browse this section.

I never really understood why all the "latest" processors (core duo, merom) have speeds of about 2.0GHz, while some older processors such as pentium 4 and pentium d go up to speeds of 3.8GHz? There has to be something in the newer CPUs that make them faster, because I thought that that GHz was the main factor in processor speed. Guess I was wrong...
 

A is for Apple

macrumors newbie
Jun 8, 2006
20
0
Wales, UK
Zwhaler said:
Ok, I didn't know where to post this, so I put it here because I knew a lot of people browse this section.

I never really understood why all the "latest" processors (core duo, merom) have speeds of about 2.0GHz, while some older processors such as pentium 4 and pentium d go up to speeds of 3.8GHz? There has to be something in the newer CPUs that make them faster, because I thought that that GHz was the main factor in processor speed. Guess I was wrong...

Well for a start theres two processers, and then comes the fact they are low voltage, and very stable at their clock speed.

You heard about the MHz myth?

Rich.
 

Fearless Leader

macrumors 68020
Mar 21, 2006
2,360
0
Hoosiertown
this is a really hard question to explain becuase the diffrence bettween the p4 and memrom becuase there were alot of tiny upgrades. while GHz's are important, its becoming less and less important due to all the other minor upgrades. Cache sizes, new technologies, and the new chips use a 65nm v.s. 90nm way of making the chips which means they can fit more stuff on the chip.
 

kevin.rivers

macrumors 6502a
Dec 4, 2005
501
0
Zwhaler said:
Ok, I didn't know where to post this, so I put it here because I knew a lot of people browse this section.

I never really understood why all the "latest" processors (core duo, merom) have speeds of about 2.0GHz, while some older processors such as pentium 4 and pentium d go up to speeds of 3.8GHz? There has to be something in the newer CPUs that make them faster, because I thought that that GHz was the main factor in processor speed. Guess I was wrong...

It used to be about Ghz, but that was just a marketing ploy. Focused has been shifted to performance per watt and multi cores.

While the pentium 4 went up to 3.8Ghz, it was not nearly as efficient as Intel's newer chips.

There are tons of other factors which are just as if not more important than CPU speed. For instance bus speeds, memory speeds(ddr2), hard drive speed(SATA) most of these are slowly being addresses.

To illistrate the shift in the CPU industry i will give you this. The current Core duo, Yonah. The next line Core 2 Duo, or Merom will be (maybe) %20 faster than the current Yonah at the same clock speeds. That is performance per watt at its best.
 

benthewraith

macrumors 68040
May 27, 2006
3,140
143
Fort Lauderdale, FL
Zwhaler said:
Ok, I didn't know where to post this, so I put it here because I knew a lot of people browse this section.

I never really understood why all the "latest" processors (core duo, merom) have speeds of about 2.0GHz, while some older processors such as pentium 4 and pentium d go up to speeds of 3.8GHz? There has to be something in the newer CPUs that make them faster, because I thought that that GHz was the main factor in processor speed. Guess I was wrong...

What makes the current processors so powerful is that there are two microprocessors instead of one single processor. It allows system processes to run in a separate processor, thereby improving speed. And no, it doesn't completely determine speed.

My old Dell Inspiron 600m had a 1.6 GHz processor that was equivalent in clockspeed to the Pentium 4 Processor 2.4 GHz w/o hyperthreading.
 

kevin.rivers

macrumors 6502a
Dec 4, 2005
501
0
Rokem said:
well the d was a dual core... isn't it?

The D's weren't true dual cores at the time, compared to say the Athlon X2's. They were hacked together by Intel to compete and performed as such.
 

Zwhaler

macrumors 604
Original poster
Jun 10, 2006
7,267
1,965
Yeah, D's werent true dual cores, unline Core Duo which actually has two cores, but I still don't like the idea of having processors being ranked by a factor other than GHz (which is what I am used to ranking them by)
 

thegreatluke

macrumors 6502a
Dec 29, 2005
649
0
Earth
A is for Apple said:
Well for a start theres two processers, and then comes the fact they are low voltage, and very stable at their clock speed.

You heard about the MHz myth?

Rich.
Core Duos don't have two processors. They have one.

Hmm, think of it this way. Let's go with a car. On a car, a core is, oh, four cylinders, and the engine is the processor. A dual core processor would be a V8 engine, but it would still be ONE engine, while a single core processor would be a V4 and not as powerful.

They both have ONE engine/processor though.

Also, them being low voltage doesn't have anything to do with their speeds. It puts a cap, yes, but at the speeds they're at, it doesn't change anything.
 

kevin.rivers

macrumors 6502a
Dec 4, 2005
501
0
Zwhaler said:
Yeah, D's werent true dual cores, unline Core Duo which actually has two cores, but I still don't like the idea of having processors being ranked by a factor other than GHz (which is what I am used to ranking them by)

Well I think you missed the boat on this one. It has been known for sometime that Ghz doesn't mean anything. There are too many factors to base perfomance and ranking solely on Ghz.

Heck why do you think AMD using perfomance ratings to name it's CPU's? Because just because Intel says it is 3.8Ghz, doesn't mean it will perform that way.
 

benthewraith

macrumors 68040
May 27, 2006
3,140
143
Fort Lauderdale, FL
thegreatluke said:
Core Duos don't have two processors. They have one.

Hmm, think of it this way. Let's go with a car. On a car, a core is, oh, four cylinders, and the engine is the processor. A dual core processor would be a V8 engine, but it would still be ONE engine, while a single core processor would be a V4 and not as powerful.

They both have ONE engine/processor though.

Also, them being low voltage doesn't have anything to do with their speeds. It puts a cap, yes, but at the speeds they're at, it doesn't change anything.

Yes and no.

Wikipedia said:
A multi-core microprocessor is one which combines two or more independent processors into a single package, often a single integrated circuit (IC). A dual-core device contains only two independent microprocessors.
 

Chundles

macrumors G5
Jul 4, 2005
12,037
493
A very, very simple way to look at it is:

Performance = Clockspeed x (operations/cycle)

So the more operations per cycle a processor can do the higher it's performance is going to be. The old 3.8GHz P4 had a very high clockspeed but due to it's architecture had a relatively low operations/cycle number. It had a very long, inefficient pipeline whereas the new Core processors have a shorter pipeline and can do far more operations/cycle than the old Pentium processors could, due in part to the short pipeline and the two cores.

Another fun fact is that the fastest processor Intel make (before the Core processors came in - remember Core Duo is not techincally a Core processor, Core 2 Duo is though) runs at 1.6GHz. It's an Itanium processor with a 16MB cache.
 

A is for Apple

macrumors newbie
Jun 8, 2006
20
0
Wales, UK
thegreatluke said:
Core Duos don't have two processors. They have one.

Hmm, think of it this way. Let's go with a car. On a car, a core is, oh, four cylinders, and the engine is the processor. A dual core processor would be a V8 engine, but it would still be ONE engine, while a single core processor would be a V4 and not as powerful.

They both have ONE engine/processor though.

Also, them being low voltage doesn't have anything to do with their speeds. It puts a cap, yes, but at the speeds they're at, it doesn't change anything.

Yes they do, 2 processors on the same housing.

I did not say that voltage has anything to do with clock speed, but i was simply giving another reason why GHz aren't important and why the new processors are an improvement.

Read carefully!

Rich.
 

bloodycape

macrumors 65816
Jun 18, 2005
1,373
0
California
kevin.rivers said:
Heck why do you think AMD using perfomance ratings to name it's CPU's? Because just because Intel says it is 3.8Ghz, doesn't mean it will perform that way.

Yeah that always confused me till all the AMD people explained it well saying that an X64 3000+ which is rater at about 2ghz is just as fast an Intel 3ghz which is true. That is why Intel moved to something like in their Centrino chipe i.e Centrino 740, 750 and so forth. Show they are beyond the MHZ wars.

Now does anyone know much about what the Centrino Duo is? Is that the same as the core duo or is it like Pentium 4 D but instead on a Centrino based chip?
 
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