Is it possible to jst increase 8 bit uP frequency to achieve performance of 32 bit uP

[matrixofdynamism]

There are various ways to measure the performance of a micro processor. Among these is the instructions executed per second.

The evolution of this electronic device has given us 16 bit, 32 bit and even 64 bit microprocessors. I am not sure if we shall be seeing 128 bit and 256 bit versions also.

My question is, is it theoretically possible to merely increase the frequency of operation of an 8 bit processor and get the same performance as a 16 bit or 64 bit machine? I don't see any reason why this would not be possible.

Also, while we make quard core and even 8 core processors, why not also move from 64 bit to 128 bit and so on to increase performance?

 

[KlausST]

Hi,

every digital electronic circuit has it´s frequency limits.
You can find this information in the datasheets.

so if a microcontroller is specified to run up to 20MHz you can not run it with 200MHz.

***
all your questions refer to the production process, density, chip area, power dissipation....

with smaller structures (modern i7 models go down to 22nm) you can increase the number of transitors and the clock speed.
This makes up to 2 600 000 000 transistors on 435 mm^2.

All the PC processor manufacturers work toimprove their limit in case of yield, density and clock speed.


It is all not that easy as it seems...

Klaus

 

[andre_luis]

I believe that technically there is no reason in principle that would impede a design house to improve performance of 8-bit uC, but the question must also pass to the commercial scope. It would not make any sense to invest in the development of an obsolete core when with an additional cost not much higher, depending on the peripherals, one can acquire a 16 and 32-bit core having a much better performance.

 

[matrixofdynamism]

OK. I have heard of desktop processors being 64 bit but not anything about microcontrollers being 64 bit. In anycase, since we are increasing the operating frequency and also adding more cores to improve performance and throughput, when are we moving to 128 bit processors?

 

[Easyrider83]

For example, multipling two 32-bit variables on 32 bit ARM Core will take 1 cycle. On 8 bit 8051 core the same operation will requere 30-40 cycles. So, the perfomance not only related to frequency.

 

[andre_luis]

OK. I have heard of desktop processors being 64 bit but not anything about microcontrollers being 64 bit

As explained before with other words, the consumer market is what dictates the course of the development of such cores. On beggining of electronic industry microcontrolers had different purpose than microprocessors, one was optimized to work standalone mainly at handset and embeeded applications, whereas other was planed on its conception to work together with other processing unities. More recently, the new 32-bit ARM architectures seems to date the technological threshold for a portable and compact system being so the practical reference for a microcontroled system.

Increasing the speed means that the overall dissipation also will increase so that the chip will need a cooling system much more efficient, what means not so compact as before. In short words, there is a limit, above which it is no longer justified to increase the speed of a microcontroller leading to achieving the speed of a microprocessor.