I just received an advertizement for a Pentium 4 3.06 GHz computer! C’mon guys. What does this description really mean anyway? Just how much difference is there (all else the same) when comparing a 1, 2 and now 3 GHz computer? I find it hard to believe that a 3 GHz computer is 3 times faster than a 1 GHz computer, but I get the feeling that is what the manufacturers are wanting us to think!
Well I’m sure that a more knowledgable doper will come along soon (paging engineer_comp_geek!), but it’s a bit tough to compare a 1 ghz comp to a 3 ghz comp.
A 3ghz comp will obviously be faster, but due to a combination of things. Faster memory, faster bus speeds (the speed at which the parts talk to each other), and of course a faster CPU.
http://www6.tomshardware.com/cpu/20030217/index.html
This site compares almost all the cpus made from 100 mhz to 3000mhz (3 ghz).
Hope this helps.
Hopefully they’ll be more knowledgeable at spelling as well.
A 3 Ghz CPU is indeed three times faster than a 1 Ghz CPU. However, as with many things the real answer is a bit more complicated.
Consider a 300 HP motor vs. a 100 HP motor. It is three times mroe powerful but dropped into a car the car will not be three times faster. So too with a computer. The actual speed of the PC is affected by many things such as bus speed, memory speed and so on. If you gave the CPU a simple problem it could hold in its head such as adding 1+1 infinitely the 3 Ghz CPU will perform about three times faster than the 1 Ghz CPU. However, most programs require data to be swapped in and out of memory, talk to the video card, get data from the harddrive and so on. While this is happening the CPU will idle till it gets what it needs. The CPU has some fancy algorithms that try to predict what it will need next to avoid this but it doesn’t always work (although they are pretty good).
In the end it is best to look and third party tests to see the relative strength of a given PC. There are tests specifically made to stress the PC (such as SiSoft-Sandra) but it has happened that PC manufacturers will tweak their systems to perform better with those tests in mind. For my money the best testing is done with real world applications…especially games. Games more than just about any other program hammer your PC. They nail video, sound, memory, hard drive, CPU like crazy. However, some tests include how fast MS-Word opens and does a certain task or a graphics program. Watch for those to get the real answer. The unfortunate thing is companies like Dell and Gateway will slap a 3 Ghz CPU in a system for marketing purposes and go cheap on the rest of the system to keep costs down. “WE have a 3 Ghz computer for $999!” I wager I could build you a system with a 1.5 Ghz CPU at the same price that would outperform the 3 Ghz system.
Well, all else being equal*, a 3GHz computer is 3 times faster than a 1GHz computer at executing instructions. Unfortunately, your computer’s job is a whole lot more than just executing instructions. The biggest job besides executing instructions is just plain moving data around (from disk to and from memory, from memory to and from the CPU, and from the peripherals to and from memory). Your CPU’s internal clock speed gives you an idea how fast it can execute instructions (which is an important part of a computer’s speed), but it doesn’t tell you how fast it can move data around. You get to a certain point and increasing clock speed doesn’t help much if your memory bus can’t keep up.
*The catch being that when comparing computers with wildly different clock speeds, “all else” rarely is equal, which is why you can’t just compare clock speeds.
So to make a long story short, no, they’re not full of it when they quote you a blazingly fast clock speed. The clock really is that fast, and it really can execute that many cycles per second. They are full of it, however, when they act like that’s all that matters.
I should note that if you use your PC just for e-mail, internet and word processing I doubt you’d notice a lick of difference between a 1 Ghz CPU and a 3 Ghz CPU. The difference might be in there somewhere but it is doubtful it will be noticeable to the end user. Mostly you will be hampered by your hard drive in this respect and it is MUCH slower than your CPU that it will likely be the limiting factor (yes I know the hard drive and CPU do entirely different things but the CPU will be waiting on the hard drive to get the data it needs).
If you use your PC for games…especially relatively new games, 3D rendering, video editing and maybe sound editing the 3 Ghz CPU will start showing its muscle over the 1 Ghz CPU…maybe not three times faster but still noticeably superior.
AS others have said a 3 gig CPU is 3 times faster than a 1 gig CPU. The problem is that the rest of the hardware doesn’t keep up with the processor speeds.
Andy Moore, one of the founders of Intel, came up with what is known as Moore’s Law. Moore’s Law states that processor speeds will double every 18 months. So far it is true. Moore’s Law will probably hit a wall in 10 years or so because it will become impossible to pack more transistors onto a chip.
Slee
Great car analogy Whack-a-Mole.
You would want to invest in not only a good CPU, but a solid motherboard (the heart of the whole system), memory, graphics card, and hard drive. If any of these are sub-standard you are going to see the whole system slow down. It is much wiser to proportion your money between them, but computers don’t sell by advertizing a “well-built system”. They sell with high numbers, low prices, and occasionally customer satisfaction (how many customers are really aware of just how fast their systems are compared to benchmarks).
And besides the clock speed there are many things that make a great processor besides how fast the internal clock is. Athlon has dropped the speed rating from its processor line because Intel took off trying to get a maximum speed. Even though an Athlon at 2.3 GHz would work just as well as a Pentium 4 at 3 Ghz, the uninformed buying public would rather go for the higher number. This is why Athlon labels their 2.17 GHz processor as a Athlon 3000+
Here’s a FOUR-gigger for you, and I use every little byte of it (graphics/photoshop guy). It’s the shit:
"How fast is the world’s fastest personal computer?
The new Power Mac G5 throttles past both the fastest Pentium 4 and a dual-processor Xeon workstation when tested using industry standard SPEC CPU 2000 benchmarks — SPECfp_base2000 and SPECint_base2000 measure the speed of a single task — either a floating-point calculation or an integer calculation — executing on a single processor. The “SPEC rate” metrics, which recognize multiple processors, more accurately demonstrate the performance of a dual processor system. The results should make your pulse race just a little bit faster."
From: http://www.apple.com/powermac/
8 gigs of RAM don’t hurt none, either.
I don’t really want to devolve this thread into an x86 vs. Apple debate, but I can’t let stockton’s assertions go unchallenged…
Characterizing the Power Mac G5 as the “world’s fastest personal computer” is quite innaccurate. The fastest personal computer as measured by the “SPEC rate” tests that Apple cites would be based on either an AMD Athlon XP 3200+, an Intel P4 3.0Ghz, or an AMD Opteron, depending on the test in question. For more information and benchmarks, see this Overclockers.com article.
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- This is headed to IMHO or the Pit, but technically: the “speed” is the actual chip clock speed of an Intel chip. Otherwise, it’s what an AMD is supposedly “equivalent” to compared to an Intel chip, and Macs have dual slower chips that together are only a bit faster than a single Intel chip but priced higher, but Macs are still better because “their chips go to eleven” or something. -But then a 3Ghz Pentium doesn’t really work three times as fast as a 1Ghz Pentium, and the reason is the 1Ghz is running Win98 and the 3Ghz is saddled with XP–so the 3Ghz is maybe about 1.5 times as fast as the 1Ghz (unless you put Win98 on the 3Ghz). Macs can’t be compared because their software, hardware and OS isn’t supposed to be used for other OS’s or on other hardware, so direct comparisons can’t be made, and something tells me that’s just the way they like it. (I prefer the price/performance of AMD myself)
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- This is headed to IMHO or the Pit, but technically: the “speed” is the actual chip clock speed of an Intel chip. Otherwise, it’s what an AMD is supposedly “equivalent” to compared to an Intel chip, and Macs have dual slower chips that together are only a bit faster than a single Intel chip but priced higher, but Macs are still better because “their chips go to eleven” or something. -But then a 3Ghz Pentium doesn’t really work three times as fast as a 1Ghz Pentium, and the reason is the 1Ghz is running Win98 and the 3Ghz is saddled with XP–so the 3Ghz is maybe about 1.5 times as fast as the 1Ghz (unless you put Win98 on the 3Ghz). Macs can’t be compared because their software, hardware and OS isn’t supposed to be used for other OS’s or on other hardware, so direct comparisons can’t be made, and something tells me that’s just the way they like it. (I prefer the price/performance of AMD myself)
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DougC:
The OP specified “all else the same” when comparing speed ratings. It doesn’t matter if you compare AMD, Intel or Motorola (Mac) CPUs as long as you compare it to another of the same manufacturer. Comparing speeds between different chips is a dicey affair and often you will find that one chip does certain tasks better than another chip while the other chip pulls ahead for different tasks. What operating system the computer runs doesn’t matter for this as a 3 Ghz chip is running at 3 Ghz regardless of the OS. Your actual performance will certainly differ but that isn’t what the OP is on about.
I will say that in theory a 3 Ghz chip is three times faster than a 1 Ghz chip but in reality you will not find an apple-to-apple comparison of a 1 Ghz vs. 3 Ghz chip. In Intel’s case you’d be comparing a P-III to a P-IV and there are important design distinctions between the two. Specifically the P-IV uses a longer pipeline to execute instructions than the P-III. This allows Intel to achieve the coveted marketing goal of haveing the ‘fastest’ clocked chip out there. As AMD and Motorola have shown higher clock speed does not relate to better performance necessarily (which is why AMD labels a 2 Ghz CPU as their model 3000 to imply the equivalent speed to an Intel chip).
The problem with the longer pipeline (think of steps an instruction has to pass on its way through the CPU) is the use of predictive branch algorithms. As I mentioned above a CPU tries to think ahead and gather info it needs before it needs it to avoid idle time. More often than not it guesses right and the use of these algorithms genuinely improves performance. However, it does not always guess correctly and when it misses the CPU has to dump everything it has been working on, get what it needs and start over. In the case of the P-IV’s longer pipeline it loses more work than an AMD chip (or P-III) in the same circumstance. This is one of those things that add up. Given the speed of a modern CPU this may happen thousands of times a second. The end result is the P-IV’s clock speed doesn’t net it the performance you might think just by looking at the number. Sadly the marketing hype works. I know many people who despite what I try to tell them figure Intel is ‘better’. I have a good friend that I’ve been working on for years and he still sticks to Intel no matter what. It’s not that Intel is bad but as a consumer they aren’t making very informed decisions and just going with the marketing hype.
Just a nitpick that I think sleestak is actually aware of - Moore’s law states that the number of transistors in a given area will double every 18 months. This doesn’t translate directly to processors getting twice as fast every 18 months, but of course there is a correlation.
Please excuse me, sleestak, I just couldn’t let it go…
Kramer
Speed is largely irrelevant. Intel were forced to reclaim space on their die in the new generation of processors to keep up with AMD’s ratings. The new P4s leave a certain piece of circuitry off (I won’t go into specifics, but iIntel removed the barrel shifter) that is used by most programming language compilers to speed up their code.
Cite:
Howdy Alereon - I also do not want to drag the thread into GD. Just a minor clarification:
It wasn’t MY assertion. I copied and pasted that verbiage from Apple’s site. THEY characterized the Power Mac G5 as the “world’s fastest personal computer.” See the link.
I WILL assert that it’s one fast mofo. 
stockton: My bad. Enjoy your dual-RISCy goodness!