If computer clocks max out somewhere around 5GHz, how is it possible for 100Gbit internet to exist? How does the computer possibly transfer that much data per second?
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A modern CPU has registers and busses 32/64 bits wide. So it can perform actions on many bits per cycle.
Hertz and bits are completely different things. Hertz is about time, bit is about volume/size. Cpu does a calculation 5 billion times a second, lets say. Internet cable carries that calculation’s outcome “chunk” from here to there either 1 by 1 or 100 pieces at a time. So a chef cooks 6 steaks at a time but the waiter might be able to carry 6 of them at once or 2 at once. Waiter and Chef are two separate things and they do two different things.
1 GHz means the processor does **something** 1 billion times per second. In modern 64 bit processors that **something** is usually one step of an instruction that contains 64 bits of information about what you are doing and where you are getting the data from to do that thing. The data itself is fetched from memory or PCIe lanes that have more than one wire, so for every time the signal changes and **something** goes into the CPU, more than 1 bit of data enters the CPU.
It is incredibly intense to do this though. First off, you need the latest PCIe or other exotic connection methods to even hook up state of the art networking cards at full speed. And you WILL often run out of CPU power try to move that much data. Special-purpose networking hardware is used to offload some of the tasks the CPU isn’t good enough at, like decoding encrypted data or forwarding (routing) data to its destination – you can get raw data transfer speeds simultaneously in/out of a relatively cheap network switch that you cannot get from a computer because the switch is so specialized while the computer’s processor is actually slower for these relatively simple, but very fast tasks.
And while high-performance datacenter machines might use 100Gb or even faster, you might see 100Gb used to carry traffic between 2 locations in a building or 2 buildings in 1 organization, but it carries data which is ultimately split up and sent to many computers at a much slower speed. So the most economical way to use 100Gb is to *not talk directly to any computer’s CPU at those speeds* and instead only use this to transfer through specialized networking gear.
Imagine your computer is like a really fast mailman, and it needs to deliver lots of letters (data) to different places on the internet. The computer’s clock speed (measured in GHz) is like how fast the mailman can walk or run. So, if the mailman can run at 5 billion steps per second, that’s really fast!
Now, think of the internet like a superhighway where the letters need to travel. Just like cars can go really fast on a highway, the internet can carry lots of data very quickly.
When you hear about 100Gbit internet, it means the internet highway can carry 100 billion letters (bits of data) every second. Even though the mailman (your computer) can run at 5 billion steps per second, the internet highway is so much faster that it can handle all those letters from many, many computers at the same time.
So, your computer can send and receive lots of data because the internet highway is incredibly speedy, even though your computer itself might not be as fast as the internet highway.
Lots of answers here are missing the point of the question.
While they’re correct that the 5ghz is referring to the CPU’s speed (how many operations it can do per second), the transfer of files from the network adapter to the hard drive is only STARTED by the CPU.
The CPU doesn’t usually move the data itself.
Instead, the adapter talks to the hard disk/RAM directly via something called “direct memory access”
https://en.m.wikipedia.org/wiki/Direct_memory_access
EDIT: Lots of great replies and clarifications to my simplified explanation
5GHz is what is today the top clock speed of the computer, but that do not mean you can’t make higher-frequency electronics. It also ot not mean that a single bit is processed per cycle. If you just use a regular 64 bits register and use one per cycle the CPU process 320 Gbit of data eacy cycle.
In a computer, there are many transistors that propagate to each clock cycle. So if you design electronics with fewer transistors the signal has to go through the frequency you can run the chip at an increase.
A single induction will be split up into multiple stages where one stage is done per cycle. the previous stage can be used by the next instruction the next cycle. So the same hardware can be reused every cycle and the same sized chip can do more, this is called https://en.wikipedia.org/wiki/Instruction_pipelining
How many steps you have to do depends on the design, Splting it up in more stages increases the clock frequency the chip can run at. The problem is making steps like that is not free, you need special electronics that store the output of one stage and send it to the next stage in the next cycle. So more and more of the worker is just this and less work is done in between. These parts also require extra transistors and use more energy.
The power usage is directly proportional to the frequency so if you increase it the power usage go up. Add to that the required extra part that uses more power. To make transistors switch faster you can increase the voltage and it increases power too.
No let’s go back ack over two decades to the https://en.wikipedia.org/wiki/Pentium_4 It use lots of stages and can manage a high clock frequency. They managed 3.6Ghz in a 65nm process back in 2006 and used 86 for a single-core CPU. The highest clock frequency varan operates at 3.8 GHz with a 90nm process in 2004
In 2006 Core 2 Duo E6600 was released. It runs at 2.4Ghz with two cores and uses 65W in the same 64nm process. but the performance per core was proximally double that of the Pentium 4 so with two cores it could reach 4x the performance with lower power usage. There were multiple reasons but a major one was it had fewer steps did more per cycle and wasted less power.
It is power and the heat of the CPU that is the major limitations today. You need to remove it all so they do not overheat. So the CPUs have a design that results in the frequency we see with multiple cores because that way you can do the most work for limited available cooling.
The transistor has shrunk to 4nm today so each switches faster and usel less power. The design has improved and do more each clock cycle. If you look at single-core benchmarks of a Core 2 Duo E6600 from 2006 and a i9-13900KS from 2023 the GeekBench 5 Single-Core was 324 vs 3093. The i9-13900KS has a tubo boos frequency of 5.8GHz which is 5.8/2.4= 2.4x the clock frequency. If we scale the result with the frequency we get 777 vs 3093 that is 4x difference
So in the last 17 years, a single core at the same frequency is 4x times faster. They spent the available power budget on more hardware that do stuff in parallel in a CPU not in a higher clock frequency because that is the new way to get high-performance
So there is nothing intrinsic that limits the electronics to 5GHz. If you need transceivers for communication interfaces you can build them in a way that allows a lot higher frequency. Because just receiving a single signal i not a lot of work you can have electronics that detect the amount of light in an optical fiber at a high enough range to detect 100 billion puls per second. It is only a single task not a lot of stuff at the same time like a CPU. The signal can then be split up in multiple parallel lines and the digital electronics that process it can run at a lot lower frequency.
100Gbit/s= 12.5Gbyte/s and if you can process 64 bits = 8 bytes at the time it you only need to do that 1.56 billion times per second. The CPUs we us have 64 bit registers. That is something a CPU can handle today.
The slowest DDR5 memory is DDR5-4000 (PC5-32000) it has 4,000 million transfers per second in a 64-bit wide bus. That is 256 Gigabit/second for a single DIMM and you have 2 channels for a standard consumer motherboard for a total of 512GBit/s. The faster memory DDR5 memory standard is at twice that but I do not know if it is implemented.
The slowest DDR4 memory is
DDR4-1600 and is 64-bit wide too. This means a single DIMM can handle 1600*64=102 Gbit/s of data. So if your computer use DRR4 memory the interface to it is over 100Gbit/s
100 Gbps is about 10 gigabytes per second. Many modern servers can process tens of GB/s. PCIE 4.0, a common standard for communication between the CPU/memory and the I/O cards, can be run at up to 32 gigabytes per second.
You are confusing “speed” (GHz) with “volume” (Gbit)
Hz tells you how many instructions per second your CPU executes,
while Gbit tells you how much data is transmitted per second.
These are measurements of two different things: a CPU is clocked in hertz (cycles per second). This is a speed measurement.
Network throughput is a measure of total data transfer and is speed x transfer size.
Think of a highway. CPU speed is similar to vehicle speed. Faster speeds mean more operations.
Bandwidth is total number of cars that pass and is calculated as speed x number of lanes. The wider the highway (bus) the more data that can be transferred at any given speed.
The 100Gb connection goes into specislised router hardware, not a generic PC / server. No single device is pushing 12GB/src of traffic.
The PC is working on 64-bit wide registers at that speed, not single bits. Intel x86 hardware takes several clocks per operation and push to main RAM is a fraction of that speed.
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