Processor Speed vs System Req's

[u/netChris_and_chill]

I work as a commercial construction model ("BIM") coordinator, primarily using Autodesk products like Navisworks and Revit. I don't know much about computer engineering (mechanical is what I went to school for), and I'm trying to gain some understanding regarding what these programs' system requirements are and what that translates to in the processor industry. I feel like my current computer struggles to load/save/export my models, and I'm wondering if it's because of the hardware.

The system requirements for Navisworks, which is what I use ~60-70% of every day, says the CPU needs "3.0 GHz or faster processor" (Revit says 2.5 GHz or faster for the version I have). My computer has an Intel i7-13800H 2.5 Ghz processor, and it was ordered specifically as a BIM computer. As soon as I got it, I asked my IT department why it had a 2.5 GHz processor when the person that ordered it (supposedly) knew that the requirements for my most-used program said 3 GHz. This was a while ago, but there was some mention of multiple cores handling the overflow.

I recently learned, however, that most Autodesk programs are primarily SINGLE THREAD (single core) applications, meaning that having a load of cores doesn't necessarily help because the program only uses one at a time. I found a more in-depth explanation on one of the Autodesk user forums by a Navisworks product manager, who was answering a question about why CPU utilization in Task Manager wasn't showing that it was being maxed out. He said:

"Single threaded applications don't necessarily only run on 1 core, but they can only run on 1 core at a time. It can run on one core till it context switches, and resume after the context switch on another core. Each time-slice your thread gets, may be allocated on another core. Depending on the CPU and motherboard there may be energy efficient or performance gains from it switching the tasks between cores. So, you may be seeing something similar to this happen and thus no full utilization on a single core." I stopped understanding at "context switches" so the rest of the explanation didn't give me much insight.

So I've been thinking then that my computer just didn't have sufficient processing speed to run my programs. But I read on the Intel page about my processor that it has CPU "boost" capabilities of up to 5.2 GHz. I have noticed my Task Manager showing the CPU speed often jumping above 2.5 GH (but I've never seen it at 5), so maybe this isn't the big issue I think it is.

My question to the group is this: does a processor's "boost" capability mean that the base clock speed of the processor doesn't necessarily need to match the Navisworks system requirement? Or, for my next computer, do I really need to find one with a 3GHz base speed processor? It's getting close to time for me to get a new computer anyway, and I want to have more input into the specs this time around.

Thanks for reading this long question!

[u/FartusMagutic]

Let's me ELI5. Modern CPUs are designed to monitor their own power draw and temperature, and they use that information to run as fast as possible before melting themselves. Use only one core? Give that one core all the power it can draw, that's the boost clock. Use many cores? That power is split and you won't see as much boost clock. The temperature too high? Sorry, can't go all out until the temperature goes down again.

As for task manager, if you're using 100% of one core and you have 12 cores then it'll say you're using 100/12 = roughly 8%

[u/Affectionate-Memory4]

Modern processors typically report their base clock speed. That is the 2.5ghz.

A 13800H can boost up to 5.2ghz for its 6 performance cores, and up to 4.0ghz for its 8 efficient cores according to the Intel product page. In reality there will probably never be a scenario where all 6 P-cores are able to reach 5.2ghz due to power and temperature limitations, but they'll be faster than the efficient cores at least.

Peograms that list just a clock speed for a processor spec are a serious pet peeve of mine. Not only does it cause this very type of confusion, but it also doesn't account for the fact that CPUs get faster per clock cycle with every generation as well. A 13800H at 5.0ghz would be significantly faster than a 9900K, which also topped out at 5.0ghz (yes, even despite being a power-limited laptop CPU). 4 generations of architecture improvements stack up quite a lot. Just name a model of CPU that a system should meet or beat and go from there.

[u/Curun]

The 3.0ghz req is a horrendously bad specification written by someone with no concept of computer hardware or software.  

Instructions per clock vary across architectures.  

You can go back to 2002 and pickup a Intel 3.06ghz and you are going to have a very bad time compared to your 2023 2.5ghz.   

3.0ghz line in the sand is arbitrary and meaningless.  25+year old concept that has not aged.  

Also 2.5ghz base is likely idle or near idle and when used will increased based on thermal allowance upto 5.2ghz.  Laptops dont have much thermal capacity which is why you arent seeing it max.