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May be a stupid question... about GHz?

Q

quentoncassidy

macrumors newbie
Original poster
Oct 31, 2010
20
0
Okay, sorry I'm not the most tech savvy person here. But I have a couple questions.

So GHz measures the speed of the processor, correct? And I've been looking at the macs that are currently for sale. ex: the mbp 13 starts at 2.4 ghz and i believe the imac starts at 3.06 or something.

However, I was looking at the specs of my current desktop (a really old one), which is a Dell Dimension 2400 with 512 mb ram, 70 gb harddrive, and according to the "system properties" it has a "Pentium(R) 4 CPU 2.80GHz 2.79GHz" processor?

So why does this old computer... pretty sure it's older than 5 years... have more GHz than the "new" mbp 13... I'd expect it to be much higher... I know the processors in current macs are better than whatever it is that I have, but why does mine say it has 2.8?

Once again, thanks for the help and dealing with my stupidity
 
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To put it simply, clock speed doesn't mean everything. Pentium 4 doesn't have the same architecture as core 2 duo or core ix. Therefore they are faster even with a slower clock.
 
Like Drew says, don't get hung up on clock speeds. However, Apple Laptops will never be on Par (speed wise) with other mainstream laptops and they'll always cost a bit more than their PC equivalents.

With a mac though, you're getting an overall better "packaged" experience consisting of too many subjective things to list here. (i.e., it ain't all about being the "fastest").
 
Richard1028 said:
Like Drew says, don't get hung up on clock speeds. However, Apple Laptops will never be on Par (speed wise) with other mainstream laptops and they'll always cost a bit more than their PC equivalents.
Click to expand...

That's not necessarily true. Yes, clock speed isn't everything (architecture and #of cores have a lot to do with it), but most mainstream laptops are using i3 or i5 dual core chips. Sure there are quad i7s available, but they are not particularly common and are rather pricey as well. I'd say the MBP is midrange to upper midrange in the CPU department, depending on the model you get. Plus you have to remember all the PCs with the celeron and pentium processors that apple doesn't use.

You are absolutely right in that they will cost more. It's apple, so you'll have to expect that, regardless of what you get.
 
Yeah, it isn't about the speed it is about the number of instructions or operations that the processor can perform over a measured time

The only time speed plays a role is with the same architecture. Then GHz is better.
 
Couple additional comments.

As newer processor families have come out, the CPUs tend to be able to do more stuff per clock cycle. So a direct clock cycle comparison is can be misleading.

Second, there's a big question about whether you'll actually see any real difference in normal usage unless you do a lot of very CPU-intensive stuff. For typical email, web, office type stuff you're simply not going to see much difference between different cpu clock rates if all else is the same. This is especially true when you're only talking about 10-15% differences in clock speed between CPU's of the same generation.
 
alust2013 said:
I'd say the MBP is midrange to upper midrange in the CPU department, depending on the model you get.
Click to expand...
Let me rephrase my original assessment:

Apple will never be the first to adopt cutting edge technology in the "speed" department. This applies to CPU's as well as the GPU.

They'll eventually catch up just about the time every other manufacturer moves on to something a little faster.
 
Richard1028 said:
Let me rephrase my original assessment:

Apple will never be the first to adopt cutting edge technology in the "speed" department. This applies to CPU's as well as the GPU.

They'll eventually catch up just about the time every other manufacturer moves on to something a little faster.
Click to expand...

That's true enough. Not sure why they wait so long to update components, especially GPU.
 
I made a comparision between three different computers earlier today.
iMac PPC G5 2GHz (processor released 2004) LG Core2Duo 2GHz (processor released 2007) and macbook pro i5 2,4 GHz (processor released 2010).

The G5 should probably be comparable with a Pentium 4 @ 4GHz. Yours is 2,8 GHz

1: http://bayimg.com/FABDiaaDc
2: http://bayimg.com/EABdLAadC
3: http://bayimg.com/EAbDNaADC
4: http://bayimg.com/FABdbaaDC

For referance, the new $6,199.00 2,93GHz Mac Pro gets 21530 points. and your computer would proably get about 700 points.

edit: 1000 points in the scale equals the $1,999 Power Mac G5 1,6GHz from 2003.
 
Last edited:
Richard1028 said:
Let me rephrase my original assessment:

Apple will never be the first to adopt cutting edge technology in the "speed" department. This applies to CPU's as well as the GPU.

They'll eventually catch up just about the time every other manufacturer moves on to something a little faster.
Click to expand...

This. Apple doesn't design their computers to be like the hulk desktop replacement laptops.
 
tunerX said:
Yeah, it isn't about the speed it is about the number of instructions or operations that the processor can perform over a measured time

The only time speed plays a role is with the same architecture. Then GHz is better.
Click to expand...

Thanks for clearing it up. And thanks everyone else. I didn't think that my processor was anywhere near as good as the ones available today.

deeddawg said:
Couple additional comments.

As newer processor families have come out, the CPUs tend to be able to do more stuff per clock cycle. So a direct clock cycle comparison is can be misleading.

Second, there's a big question about whether you'll actually see any real difference in normal usage unless you do a lot of very CPU-intensive stuff. For typical email, web, office type stuff you're simply not going to see much difference between different cpu clock rates if all else is the same. This is especially true when you're only talking about 10-15% differences in clock speed between CPU's of the same generation.
Click to expand...

Well I think that no one can really argue that my computer is out of date... I'm only a junior in high school and that's the desktop that my family shares.. Trying to convince my parents to get a new iMac. I think it will benefit them, even though I'll be gone in a couple years. And when I go to college in summer 2012, I know that I'll be going mac..
 
quentoncassidy said:
So why does this old computer... pretty sure it's older than 5 years... have more GHz than the "new" mbp 13... I'd expect it to be much higher... I know the processors in current macs are better than whatever it is that I have, but why does mine say it has 2.8?
Click to expand...

The "GHz" is the clock speed of the computer. You can compare it to the RPM of a car's engine. A car with higher RPM is not necessarily faster than one with lower RPM (Bentley going 70 mph at 1700 rpm, and some tiny car going 70 mph at close to 4000 rpm). Or if you compare cars with diesel and petrol engines, the petrol engine usually has much higher rpm while going at the same speed.

The P4 processor from years ago needed many more cycles than a modern processor to do the same work. Starting with Core 2 Duo, the processor can perform up to four operations per clock cycle, while on the P4, lots of instructions actually took multiple cycles. Before the first official Macintosh computers were released, Apple shipped systems with 3.6 GHz P4 processors to developers. The first MacBook from 2006 with a 1.8 GHz Core Duo ran faster. One reason for this discrepancy was that Intel discovered that customers just looked at MHz and GHz, and the engineers were told to increase the clock speed - with no regard how much work the processor actually could do per second. AMD did strike back with a truly ingenious plan: Where Intel built a processor running at 2800 MHz = 2.8 GHz, AMD just called their processor an "AMD 2800" :D

The latest processors will run maybe 40 percent faster than the Core Duo from 2006 at the same clock speed. And compared to the P4, the new processors all have multiple "cores" and each core is basically one complete processor. So an iMac with a quad core processor basically has four processors instead of one, making it again up to four times faster.


Richard1028 said:
Let me rephrase my original assessment:

Apple will never be the first to adopt cutting edge technology in the "speed" department. This applies to CPU's as well as the GPU.

They'll eventually catch up just about the time every other manufacturer moves on to something a little faster.
Click to expand...

So who was shipping desktop computers with 12 cores before Apple did?
 
Clock speed is not completely irrelevant but only one of some numbers.
Another von is IPC Intruction per Clock i.e. what can it get done in one clock.
The thrid important one would be cores. How many "clocks" run in parallel. On a modern day highend Desktop GPU (Graphic Processor) that is 1000+ cores.

When you compare an old architecture like a Pentium 4 to new ones like a Core iX the first thing to look at it the ICP and Cores the last it clock speed/rate. That is why people usually say clock speed can only be a usuful number if you compare the same architecture.

The best you can do if you are non tech savy and don't want to inform your self too much, which is nowadays exceptionally difficult with even the confusing numbers and names CPU manufactures assign to their chips, is to look a benchmarks.
Just look the CPUs up you find mentioned on some spec sheet.
CPU comparison notebookcheck (it's only mobile processors afaik, for destkop go to tomshardwareguide.com)
same thing for GPU comparison

You Pentium 4 2,8Ghz ranks on 338 in this list with about 600-700 in 3DMark06 (which is the most useful number out of all those listed)
The 3Ghz core i3 of the cheapest imac should be equally fast as a mobile core i7 640M which offers a 3dMark06 score of 3200.

Compare those numbers only if from the same website because they can change when run a different resolution and settings. As you can also see the cheapest desktop CPU is about as fast as the most expensive mobile CPU (that Apple offers).
But those numbers are the easiest reliable enough thing. It gets more complicated once you count in which architecture is better at specific programs. A core iX is in some cases no better than the last Gen. Core 2 Duo but in others it is much better. If you want an accurate comparison for your needs you will have to ask in a forum like this (or read a lot).
 
dusk007 said:
Clock speed is not completely irrelevant but only one of some numbers.
Another von is IPC Intruction per Clock i.e. what can it get done in one clock.
The thrid important one would be cores. How many "clocks" run in parallel. On a modern day highend Desktop GPU (Graphic Processor) that is 1000+ cores.

When you compare an old architecture like a Pentium 4 to new ones like a Core iX the first thing to look at it the ICP and Cores the last it clock speed/rate. That is why people usually say clock speed can only be a usuful number if you compare the same architecture.

The best you can do if you are non tech savy and don't want to inform your self too much, which is nowadays exceptionally difficult with even the confusing numbers and names CPU manufactures assign to their chips, is to look a benchmarks.
Just look the CPUs up you find mentioned on some spec sheet.
CPU comparison notebookcheck (it's only mobile processors afaik, for destkop go to tomshardwareguide.com)
same thing for GPU comparison

You Pentium 4 2,8Ghz ranks on 338 in this list with about 600-700 in 3DMark06 (which is the most useful number out of all those listed)
The 3Ghz core i3 of the cheapest imac should be equally fast as a mobile core i7 640M which offers a 3dMark06 score of 3200.

Compare those numbers only if from the same website because they can change when run a different resolution and settings. As you can also see the cheapest desktop CPU is about as fast as the most expensive mobile CPU (that Apple offers).
But those numbers are the easiest reliable enough thing. It gets more complicated once you count in which architecture is better at specific programs. A core iX is in some cases no better than the last Gen. Core 2 Duo but in others it is much better. If you want an accurate comparison for your needs you will have to ask in a forum like this (or read a lot).
Click to expand...

Makes me feel like my computer's ancient and unable to wait to buy a new one.. haha
 
quentoncassidy said:
Okay, sorry I'm not the most tech savvy person here. But I have a couple questions.

So GHz measures the speed of the processor, correct? And I've been looking at the macs that are currently for sale. ex: the mbp 13 starts at 2.4 ghz and i believe the imac starts at 3.06 or something.

However, I was looking at the specs of my current desktop (a really old one), which is a Dell Dimension 2400 with 512 mb ram, 70 gb harddrive, and according to the "system properties" it has a "Pentium(R) 4 CPU 2.80GHz 2.79GHz" processor?

So why does this old computer... pretty sure it's older than 5 years... have more GHz than the "new" mbp 13... I'd expect it to be much higher... I know the processors in current macs are better than whatever it is that I have, but why does mine say it has 2.8?

Once again, thanks for the help and dealing with my stupidity
Click to expand...

The Pentium 4's have only one core .... on a much slower system architecture.
The Core 2 Duos have 2 cores on a system architecture which may 1.5x-2x faster than the Pentium 4's. (system architecture as in the speed of the link between RAM and CPU, for example)
And the Core ix is even faster than the Core 2 Duo
 
Think of the computer as car; you have a old 4L V8 from 40 years ago… it will not have the same power as a new 4L V8 from today; sure your computer isn't that old, but in terms of technology, that Pentium 4 processor is ancient.
 
alphaod said:
Think of the computer as car; you have a old 4L V8 from 40 years ago… it will not have the same power as a new 4L V8 from today; sure your computer isn't that old, but in terms of technology, that Pentium 4 processor is ancient.
Click to expand...

Agreed, was gonna write this same comparison as i was reading through! Power as well as efficiency i.e. Miles Per Gallon. Power is affected by build quality allowing for better heat dissipation and more packed in a smaller size!
 
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