As you start to ramp up processor speed, you have to worry about leakage. As a result, you need to raise voltage in order to keep the chip stable. As a result, you have increased heat. And because you need exponentially more voltage increases as you increase speed, heat ramps up faster then clock speed.
The orignal Intel roadmap for Netburst ( Pentium 4 ) was to increase speeds to that level of 10Ghz. But as said above heat and voltage became too much of an issue, also the more efficient AMD processors of the time were faster despite being clocked slower. So they basically did a 180 in 2006. They focused on efficiency and using multiple cores over 1 very fast core. By combining the best of the older Pentium III Goldmine processors and the current mobile processors of the time they were able to make the Core2 lineup. It was more efficient and cooler and much more powerful clock for clock than the Pentium 4s were. Like a Core2 chip at 1.8Ghz beats a Pentium 4 at 3.6Ghz. The Core2 line also put Intel ahead of AMD again and they have not lost that advantage since.
Processor speeds are increasing. But headline clockspeeds aren't increasing very fast these days. Once upon a time, Intel would have you believe they were the same thing.
(Remember their infuriating boast about the 2GHz clockspeed of the Pentium 4? Everyone who knew anything about computers knew this was utterly disingenuous seeing as it was outperformed by AMD chips running at 1.5GHz).
As transistor technology and manufacturing processes improve, it will be possible to eke out marginally higher clockspeeds but most of the low hanging fruit has already been picked.
There is another issue of course: sandbagging. Ie the fact that Intel doesn't increase its stock clockspeeds because it doesn't have to. There is nobody out there making chips that force Intel to up their game (with the exception of the low power portable device market where ARM is a genuine, proper competitor). That means that Intel can release chips that are perfectly capable of 4.5+ GHz, yet only market them as 3.5 GHz parts knowing the competition is nowhere in sight.
Looking it another way, you could argue that Intel HAVE increased their clockspeeds dramatically in the past 10 or so years. The Pentium 4 topped out at 3.8GHz and that was an architecture that was specifically designed to reach high clockspeeds. The current line does not have a design that's optimised for high clockspeeds and yet they still reach around 4.8GHz on average. And they manage to achieve it with 4 cores whereas the Pentium 4 only had 2 cores max.
It doesn't matter though. Today's chips are massively, massively faster than those of yesteryear. Each generation is at worst an incremental improvement over the last. Like compound interest that accumulates hugely over time.
For fun, I still run CPU Mark 99, simply because I've done so on every processor I've ever had. For comparison, my Pentium 200MMX which I had in 1999 gave a score of 12. My core i7 2700K (at 4.8GHz) scores 745. Running 8 instances simultaneously yields a score of 4103. That's a heck of an improvement in 13 years.
Its been there at 3.5 GHz. these processor speeds for a long time. why intel can't increase the process speeds to 10 GHz or more... for desk top PCs.
How do you define "speed"
If you define speed as the clock rate, like the 3.5 you mentioned, the answer is power and heat.
If you define speed as how powerful the computer is, and how much work can it do, then there has been a very large jump in capability.
Here are a few reasons:
1) The increase in the number of cores(threads) from one to 2 4 6 and more.
Each one operating at 3.5 can do more work.
2) The IPC or instructions per clock has gotten better with better architecture.
3) Larger internal cache lets the cpu do more with data that is kept in cache vs. going to ram to get it.
sir, i wanna ask one thing that there is the speed of communication Chanel up to 10GBpS but the processors speed is not increasing but u have motioned that heat is a reason for that...
But for the communication channel there will also be heat. The technology that are being used to speed up (reduce the heat for) communication channel the same technology also can be used to reduce the heat for processor.
So, Now i am confused again....