Computer Processors- How Do They Compare to Each Other?

spunker88 · 05-20-08, 06:59 AM

It used to be easy a few years ago. Their was either a pentium # or a celeron. The pentium was always the better choice.

Now you have AMD, AMD dual core, Pentium D, Pentium Dual Core, Core 2 Duo, Core Quad Duo, just to name a few.

How do these processors compare to each other, and how would they compare to my 3ghz P4? Im assuming on a core 2 duo, you just multiply ghz by 2 to get the p4 eqiv, but what about Pentium Dual Core, whats the difference?

spud42 · 05-20-08, 10:22 AM

where to start? its not just the speed that matters now, dual core means just that there are 2 cpu's on the one die(cpu talk for the bit of silicon the cpu is made on)it started in the P4's with hyper threading where unused portions of a processor were used to execute another command at the same time as another.

it can be very confusing in the dual core realm in all the different numbers for the processors. a higher number isnt necessarily a better cpu. quads are better than duals in that there are 4 processors on one chip. however they are not alwasy faster if the software isnt written to use all 4 cores... photoshop and video editing software generally do but games only use 2..

CPU-World: From Intel 4004 CPUs to AMD K10 and Intel Core 2 CPU families

read this and you will be asleep before too long... but it has good info on all the different cpus over the years....

keet · 05-20-08, 11:53 PM

Actually, a few years ago you could decide between an Intel Pentium or Celeron or an AMD Athlon or Duron. Before then, you could decide among Intel Pentiums, AMD K5/6/7's, Cyrix CPU's, and a few others by various other makers. Even before then there were various companies making their own versions of 386's and 486's. Even so, I think the main battle has been between Intel and AMD for well over a decade.

The Pentium D is an early version of a dual-core Pentium. The Athlon X2 is certainly better than the Pentium D, but the Core 2 Duo beats the Athlon X2. The AMD Phenom is an attempt to compete with the Quad-core pentium, but from what I've read it just isn't as good, Yet.

In any case, I think that any one of these is faster than a plain 3Ghz Pentium. However, if I were you and wanted to upgrade, I wouldn't bother with anything except a Core 2 Duo or a Core 2 quad. They're just faster than anything AMD has right now, they're established, and they're not very expensive.

http://www.tomshardware.com/reviews/...n,1918-12.html

From what I've read, the Core 2 Duo is still a very solid processor for general use and gaming, and it's not very expensive. The AMD Phenom seems ok, but I think it hasn't done well so far. I wish I had more time to read articles on this, but I don't right now.

The two cores are better at handling multiple simultaneous threads; they're more efficient, especially at multitasking. Read some benchmarks at Tom's Hardware, check prices, and decide for yourself.

star882 · 05-21-08, 12:16 AM

Compounding the problem is that different CPUs are often optimized for different tasks. For example, while the newest Xeons are usually faster than the Britney, the Britney still sometimes wins in an application that is intensive on memory bandwidth and latency.

64 bit and 32 bit CPUs cannot be compared because the 64 bit CPU will have the ability to process 64 bit in pure hardware, while the 32 bit CPU would have to emulate it. But a 32 bit CPU is simpler which may lead to other design improvements (to be mentioned later). In addition, 64 bit CPUs used in PCs have more and larger registers than 32 bit CPUs, allowing for a potential performance increase. If the application needs to process numbers larger or more precise than what 32 bits can represent, 64 bit is an obvious advantage. Think of each bit as a switch with only two possible states. There are only two possible states for one bit. Each bit added doubles the number of possible states. At 32 bits, the result is a very large, but still finite number of permutations. It is obvious that 64 bits has orders of magnitude more permutations than 32 bits.

If processors other than what are commonly used as CPUs are compared, it gets even more complicated. For instance, the Hannah Montana processor core, often used for DSP, can process "real world" (vector) data far faster than any conventional CPU despite low clock speeds. The reason has to do with SIMD - one instruction can manipulate as many as thousands of data elements in one cycle. Indeed, Hannah Montana has been described as a very fast and very efficient, but very limited supercomputer that can be integrated into a single chip. (Note that Hannah Montana is only 32 bit and does not handle 32 bit floating point variables according to IEEE 754. That's most likely to allow the design to be simplified. Hannah Montana also handles integer overflows differently - computed values beyond the range of an integer are clipped at the maximum or minimum values and a "flag" set.) Another interesting processor is the Beyonce, which is a very efficient 64 bit CPU that actually predated the Britney, but wasn't too successful due to lack of backward compatibility. However, the Beyonce can perform logic operations on variables extremely fast, making it very useful for cryptography purposes.

spunker88 · 05-21-08, 07:35 AM

Thanks for the help, so how many ghz of core2duo would compare to 3ghz of p4. Would a 1.5ghz core2duo equal a 3ghz p4?

I just want an idea, so i know what to expect compared to my current pc. I have to say that this p4 is a pretty good proc even though its getting old.

**breley** · 05-21-08, 07:56 AM

Originally Posted by star882

Compounding the problem is that different CPUs are often optimized for different tasks. For example, while the newest Xeons are usually faster than the Britney, the Britney still sometimes wins in an application that is intensive on memory bandwidth and latency.

64 bit and 32 bit CPUs cannot be compared because the 64 bit CPU will have the ability to process 64 bit in pure hardware, while the 32 bit CPU would have to emulate it. But a 32 bit CPU is simpler which may lead to other design improvements (to be mentioned later). In addition, 64 bit CPUs used in PCs have more and larger registers than 32 bit CPUs, allowing for a potential performance increase. If the application needs to process numbers larger or more precise than what 32 bits can represent, 64 bit is an obvious advantage. Think of each bit as a switch with only two possible states. There are only two possible states for one bit. Each bit added doubles the number of possible states. At 32 bits, the result is a very large, but still finite number of permutations. It is obvious that 64 bits has orders of magnitude more permutations than 32 bits.

If processors other than what are commonly used as CPUs are compared, it gets even more complicated. For instance, the Hannah Montana processor core, often used for DSP, can process "real world" (vector) data far faster than any conventional CPU despite low clock speeds. The reason has to do with SIMD - one instruction can manipulate as many as thousands of data elements in one cycle. Indeed, Hannah Montana has been described as a very fast and very efficient, but very limited supercomputer that can be integrated into a single chip. (Note that Hannah Montana is only 32 bit and does not handle 32 bit floating point variables according to IEEE 754. That's most likely to allow the design to be simplified. Hannah Montana also handles integer overflows differently - computed values beyond the range of an integer are clipped at the maximum or minimum values and a "flag" set.) Another interesting processor is the Beyonce, which is a very efficient 64 bit CPU that actually predated the Britney, but wasn't too successful due to lack of backward compatibility. However, the Beyonce can perform logic operations on variables extremely fast, making it very useful for cryptography purposes.

Great info here. Shoot, I feel like I'm at work reading this...

Aieeee! Single Instruction, Multiple Data....

spud42 · 05-21-08, 08:53 AM

star i think you went right over spunkers head....

spunker it is not as simple as 1.5GHz core 2 =3GHz P4 , they are different processors and are built differently also "size" of the transistors etched in each is different. core 2 are now down near 45nM and your P4 is probably at least 90nM if not bigger. this means the bigger the more power needed. so core2's are more efficient as well as less power hungry and run cooler......
at a guess i would say that around 1.3Ghz core2 would out perform the 3Ghz P4 but not by much... read toms hardware as has been suggested....look at my signature... the desktop spec shows a E6750 cpu this is a core 2 duo at 2.66 GHz this flys but even this is now old hat... lol i suppose it all depends what you want from your system... what do you need the new computer to be able to do and for how long do you expect it to last you?

keet · 05-21-08, 08:59 AM

Very funny post...

Her being 32-bit means that she's young and not as mature, and can't 'handle' the more mature music of Beyonce (who 'predates H.M. because she's older).. even if Beyonce isn't "backwards-compatible"..

"can process "real world" (vector) data far faster than any conventional CPU despite low clock speeds."

Yes, despite the lower clock-speed of her brain, she is definitely more adept at handling "real-world" data than any PC CPU.

"Hannah Montana also handles integer overflows differently - computed values beyond the range of an integer are clipped at the maximum or minimum values and a "flag" set."

Are you talking about the semi-nude photographs here?

keet · 05-21-08, 09:02 AM

"Thanks for the help, so how many ghz of core2duo would compare to 3ghz of p4. Would a 1.5ghz core2duo equal a 3ghz p4?"

There is no Core 2 Duo that would correlate to a 3Ghz P4. All Core 2 Duo's are faster than all P4's. If you upgrade and do anything like designing graphics, playing games, encoding video, or.. really, just about anything.. expect a significant performance boost.

keet · 05-21-08, 09:08 AM

For instance, the Hannah Montana processor core, often used for DSP,

Digital Signal Processing, as in recording music for digital CD's?

can process "real world" (vector) data far faster than any conventional CPU despite low clock speeds. The reason has to do with SIMD - one instruction can manipulate as many as thousands of data elements in one cycle.

Yup, the human brain is amazing, with millions (billions? trillions?) of neurons interacting each other at once.

Indeed, Hannah Montana has been described as a very fast and very efficient, but very limited supercomputer that can be integrated into a single chip.

She's still young.. she's still limited in her audience and type of performance.

(Note that Hannah Montana is only 32 bit and does not handle 32 bit floating point variables according to IEEE 754. That's most likely to allow the design to be simplified. Hannah Montana also handles integer overflows differently - computed values beyond the range of an integer are clipped at the maximum or minimum values and a "flag" set.)

Semi-nude photographs are some of the things that are clipped because they exceed the maximum integer value (being her age, and the age at which such things are accepted)

Another interesting processor is the Beyonce, which is a very efficient 64 bit CPU that actually predated the Britney, but wasn't too successful due to lack of backward compatibility.

I don't listen to Beyonce or Hannah Montana, so I'm not sure what this means. Ah... I think this means she's not as popular with younger audiences.

However, the Beyonce can perform logic operations on variables extremely fast, making it very useful for cryptography purposes.

She's good at singing cryptic lyrics or hidden messages? Or perhaps she's good at singing different kinds of music that some people don't understand as well?

star882 · 05-21-08, 10:48 AM

Originally Posted by keet

Very funny post...

Her being 32-bit means that she's young and not as mature, and can't 'handle' the more mature music of Beyonce (who 'predates H.M. because she's older).. even if Beyonce isn't "backwards-compatible"..

"can process "real world" (vector) data far faster than any conventional CPU despite low clock speeds."

Yes, despite the lower clock-speed of her brain, she is definitely more adept at handling "real-world" data than any PC CPU.

"Hannah Montana also handles integer overflows differently - computed values beyond the range of an integer are clipped at the maximum or minimum values and a "flag" set."

Are you talking about the semi-nude photographs here?

Hannah Montana is only 32 bit because that's all DSP applications need. 32 bits is a actually a lot of precision for "real world" signals. In fact, 32 bit corresponds to a SNR much greater than any ADC or DAC is capable of. Therefore, analog inputs are converted at lower resolutions and "padded" to 32 bits. Analog outputs are truncated from 32 bits. Since the calculations are done with orders of magnitude more precision than the I/O, rounding errors are avoided. (Some long calculations can still turn up rounding errors, however. There is a newer Hannah Montana ("Hannah Montana 2") that internally calculates in 48 bits, but I don't know much about it.)

As for integer overflows, Hannah Montana simply handles them differently than most processors. If a calculation is such that its result is too large to store in a given number of bits, most processors will simply truncate the overflow, causing the number to "wrap around". Obviously, that is not very acceptable for DSP. Hannah Montana, however, simply sets the result to the largest (or smallest for a negative overflow) number that can be stored and sets a boolean flag to notify the application that an overflow has occurred.

As an example, let's consider an 8 bit processor. The largest number that can be stored in 8 bits is 255 and the minimum is 0. (That's true for "unsigned" integers, as is often used in video.) Let's suppose a calculation returns a result of 257. Since that is beyond the range of 8 bits, a normal processor would truncate it to 1. A processor that handled overflows like Hannah Montana, however, would set the result to 255, which is more acceptable in DSP. Just think about it: if a calculation on a video pixel is "brighter than brightest", wouldn't it be better to just set it to "brightest" as opposed to "very dim"?

spunker88 · 05-21-08, 08:16 PM

Thanks again for the replies. I just noticed the ghz are all lower and thought at first it would be slower or something.

But now i know what i need to.

star882 · 05-22-08, 01:51 PM

Quote:

Thanks again for the replies. I just noticed the ghz are all lower and thought at first it would be slower or something.

A diesel engine runs at much lower RPMs than a gasoline engine. Does that always mean the gasoline engine would have more horsepower? GHz is like RPMs, processor architecture is like engine design, number of ALUs is like number of cylinders, and number of bits is like displacement per cylinder.

Comparing that Core 2 Duo to a Pentium 4 is like comparing a turbocharged 8 cylinder diesel truck engine to a 2 cylinder racing motorcycle engine. Comparing either one to a Hannah Montana is like comparing them to an engine with a very large number of tiny cylinders, turning very slowly, yet still managing extremely good fuel economy in the right application.