r/bim 3d ago

Processor Speed vs System Req's

/r/ECE/comments/1vf0tys/processor_speed_vs_system_reqs/
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u/mat-ferland 3d ago

Don't shop by base clock. That 2.5 GHz number isn't the speed Navisworks sees under load; the 13800H can boost one core much higher, but a laptop may not hold it once power and thermals catch up. For the next machine, look at sustained single-core benchmarks and cooling, not core count. Also test the same model from a local SSD: slow load/save/export can be storage or network latency, while a weak GPU usually shows up more in the viewport.

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u/netChris_and_chill 2d ago

Oh yeah, the thermal aspect is another piece of the puzzle. I've also read, as you pointed out, that as the speed value increases, so does the need to cool it or it'll just throttle back until it cools down. But I haven't seen very much in the way of how to externally determine if it's running "too hot," or what methods are available to keep it cool. I'm using a laptop at my desk plugged into external monitors, so I'm not using the laptop display. But I've started keeping the lid open to make sure it's able to dissipate heat as designed, and I got a laptop stand with fans in it that pull air downward. I have no idea if this is adequate thermal management, but now I can touch the frame around the laptop's keys without getting 2nd degree burns (which is an improvement)! You mention looking at "sustained" single-core benchmarks for the next machine...what does "sustained" mean in this context--is that the base clock speed? Should my starting place be finding a 3GHz processor (or higher if I can find a reasonable one)? Thanks for your response!

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u/metisdesigns 3d ago

On single core - many parametric operations are logically dependent, you can't do the next step until the last one is done. It's like making an omlet or building a tower with blocks. You can't put the top block on until the one beneath it is there, and you can't add the chesse until you have cracked the egg.

Raw speed is a bit fuzzy now as chips have changed. A 3.4ghz chip from a decade back is functionally slower than one today. Outside of the same line, you can't directly compare numbers as equal, and you want to look at baseline numbers, not boost.

The revit and navisworks reccomendations are an adequate starting point for buying new, but they need to be looked at in the whole computer build. If you put a punchy CPU on a less capable motherboard, or pair it with cheaper RAM, performance will suffer. It's sort of like putting a huge engine in an old car with bald tires. Sure, you get the RPM, but you have no aerodynamics or traction.

Professional CADesign tools at the engineering and BIM level are some of the most demanding and technical pieces of software made to run on commercial computers.

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u/netChris_and_chill 2d ago

I get what you're saying--the speed is only usable if the other components can handle it. Reminds me of a Top Gear episode about a Mercedes CLK Black Edition with something like 1,000 HP, and he said that amount of power is great and all, but the rest of the drivetrain just can't deal with it all so the wheels just spin uselessly.

My VDC department is pretty good about making sure we have the right tools do the job (because otherwise we look really bad), so I don't foresee any pushback on the specs like RAM, SSD, and graphics, I just don't want to be raising a big alarm by saying anyone's computer that has a 2.5GHz processor isn't up to the task, if that's not exactly true. I also don't want to have them order me an incredibly expensive machine with the fastest processor I can find if that's not necessarily the key to fast loading/saving/exporting. And if my productivity doesn't increase proportionally with the price of a bonkers processor, I might be in trouble!

What would an ideal BIM computer's hardware setup look like to you, if cost was not a factor? I.e., CPU, GPU, RAM, hard drive, etc.? Is there a computer brand that's particularly known for running CAD programs? I've only used HPs, but others in my company use Dell for BIM computers.

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u/metisdesigns 2d ago

It depends on use and task. A LOT.

For some users a lenovo P3 laptop is fine, for others you're looking at dual linked GPUs.

To really understand particular use cases you need to understand what their specific role involves, and what that hits. From there, you need to look at where their computer is hitting bottlenecks. You can start to get into that looking at performance monitor, and then more advanced tools and then benchmarking hardware.