For brevity (and this has turned into a long post even so), I have simplified some terms and cut some deeper explanations of how registers etc. work.
A computer reads the bits in 8 bit blocks, each bit is flipped on and off (carrying current or not) to represent a 1(on) or 0 (off), those are your transistors in the RAM chips. Those 8 bits are then a byte - early computers also used a half a byte, or a nibble, yes, seriously!
Early home computers worked with 8 bits, so they read one byte at a time and processed it. That meant that they could deal with values from 0 to 255, or signed -127 to +127. They could use 16 bits, by combining 2 bytes for larger numbers, but they did that in software, either by working on the bytes or using a pair of registers.
If even bigger numbers were needed, the software had to calculate that itself, by using multiple bytes and performing the math on each bit and byte at a time, and carrying over the result etc.
Modern computers work with 8 bytes at a time, for 64 bit registers and 64 bit numbers - they can work on smaller numbers of bytes, down to a single byte for ASCII characters, for example, but those are pushed into a 64-bit register and the remaining bits over the first 8 are then ignored.
That means that we can have huge numbers calculated automatically by the processor these days (18,446,744,073,709,551,615 for unsigned and --9,223,372,036,854,775,808 to +9,223,372,036,854,775,807 for signed).
A floating point number is something totally different. Processors generally work in integers (whole number, with no fractions, no decimal points). A floating point number is a number with a decimal point. In the old days, the processor and the software had to manipulate integers and work out the floating point part the hard way. Modern processors include a so-called math co-processor (they were originally additional chips on early Motorola 68xxx and Intel 80x86 processors, but are usually integrated into the main CPU as an additional processing unit these days). The encoding of the floating point (we’ll just take 64-bit for brevity) ranges from a minimum value of approximately 1.175494351 E-38 to a maximum value of approximately 1.7976931348623158 E+308.
Integers and Floats (decimal numbers) are not interchangeable, and if you want to move from and integer to a float or back, you actually have to go through some long winded conversion to format the number correctly, so that the CPU doesn’t choke on it.
Like in the 8 bit days, if you need really big numbers, you need to combine multiple clusters of 64-bits and deal with each 64-bit block on its own, then take any carry into the next one. It isn’t as efficient as doing 64-bit math, but it is possible, with a lot of work.
That is a very brief introduction of how a computers work with bits and bytes.
It isn’t the number of transistors that makes up the speed. The Intel chips have a lot more transistors than some ARM processors, but on certain types of calculations a smaller ARM processor will be quicker, due to its design. At the end of the day, there are many factors that come into the equation of what makes the fastest computer:
- Clock speed - how fast the processor work, essentially how many instructions cycles the processor can perform per second, with modern CISC processors, this is a bit of a misnomer, many instructions can take several cycles to execute and with multi-core processors, sometimes one core will have to wait for another to finish execution, before it can continue, because it needs a result from it, for example. The clock speed is, shall we say, the theoretical maximum number of “simple” instructions that the processor can perform per second.
- Bus and memory speed - this is how fast the processor gets information from memory and other peripherals on the system bus. The faster the bus and the memory, the more information you can pass to the CPU or put back into memory in a given period of time. When the system is busy moving bits into the CPU cache, for example, the processor can’t generally do anything, as it is waiting for the relevant information to become available
- Caching - how the CPU manages small amounts of memory in its cache of very fast (and very expensive) memory. A computer with 64GB RAM can hold a lot of data, but a processor has a cache of a few hundred MB, or thousandths of a gigabyte, of fast cache memory. You could use more cache memory, but the price of the computer would quickly climb into the tens of thousands, if not hundreds of thousands of dollars.
- Number of core - the more cores, the slower the clock speed, but the more calculations can be performed at the same time - assuming the work being done can be parallelized and the processing pushed to the other cores; some tasks can’t be parallelized and can only run on a single core, so pushing more cores at it won’t improve performance.
Computers and CPUs trade all of this off to give certain levels of performance - and is also why multi-core processors can shut down cores and boost the speed of a single core, to calculate something more quickly, if the task can’t be done in parallel.
Apple have moved most of the memory and storage onto the same package as the CPU (and GPU, NPU etc.), meaning huge numbers of transistors, all running on a close bus and not having to travel over long distances and not running through subsidiary components. This means they are incredibly fast, even if the “CPU” itself doesn’t have all of those transistors itself.
But there are negatives, you only have a comparatively small amount of memory and storage built into the package. With Apple devices at the moment, once you have used all that memory, that’s it, you can’t add any more. With Ultra chips, you are up to 192GB of RAM, but that is two packages “welded” together. That might sound like a lot, but modern, high power servers often have access to terabytes of RAM, for example. The same goes for storage, the first few GB or TB of storage are quick, but if you need more - modern high power systems use petabytes of storage - you need to put that additional storage out on the slower bus that every other computer also uses…
It is all about trade-offs and flexibility, price and common sense. You really need to work out what you are trying to achieve and how much you can spend and see what best fits your needs.