Is Grasshopper/Rhino 6 really this slow on Macs?

I’m new to Rhinoceros, I just installed a trial version of Rhinoceros 6.22 on my relatively up to date MacBook Pro (specs below) so that I can attend a introductory course on Grasshopper.

The teacher distributed a file with ‘.gh’ extension and 122 kb size to the students with some components and notes in it.

My colleagues, who have Windows notebooks, are able to open that file in a few seconds and work easily on it, zooming in and out, creating and connecting components, sliding sliders etc.

On my Mac, the file took about 2 minutes 50 seconds just to open.

Every simple operation, such as zooming in and out, gives me the beach ball…

And this is a very simple file, just for learning purposes, with no complicate calculations or elaborate geometry.

I was warned that Rhino/Grasshopper would have lower performance on Mac than on Windows, but this is close to unusable.

Is there something wrong with my computer or my installation, or is it the expected behavior for Grasshopper on a Mac?

Is there something I could do to improve its speed?


MacBook specs:
MacBook Pro (15-inch, 2017)
2,9 GHz Intel Core i7
16 GB RAM 2133 MHz LPDDR3
Radeon Pro 560 4 GB
Intel HD Graphics 630 1536 MB
MacOS Mojave 10.14.6

This is the file we are using in the class:

Aula 02 - intro ao (118.7 KB)

That’s slower than on my MacBook Pro that is slower and older. So no not normal behavior.
You might need to run _SystemInfo in Rhino (it’s a command) and post back the resulting info it gives.

Opened here in 37 seconds. After that navigating is smooth

Here it takes 50 seconds on a mabook pro late 2013, yours should be way faster.

Zooming and panning is perfectly smooth here aswell.
My computer has an Nvidia card, don’t know if that might be the problem.

I timed it again. I opened Rhino, then Grasshopper, then chose ‘Open Document…’ and selected the attached file. From the moment I click ‘Open’, it took 2m58s to show Grasshopper’s canvas.
The System Info is attached.
Rhino System Information.txt (2.4 KB)

Don’t really know why this is happening on your machine. btw: When I open it on my windows computer it takes <1 second.
So something is definitely wrong with gh on the mac

Yep, here too…

Thanks for the reports.

I was told that Rhino does not use the multicore capabilities of processors. Is it true?

Would it be possible that it runs slower in a newer MacBook because, although the total speed of a multicore chip is faster, the speed of a single core is slower than an older macbook?

I don’t notice any performance issues with other apps such as ArchiCAD.

Opened in about 40 seconds on my 2016 MacBook Pro with similar specs than your 2017 model!

Don’t worry about the performance of your Mac. I’ve personally dealt with huge projects than opened way faster!! Somebody should tell your teach that Grasshopper is not a text editor! :wink:

Why not use a nice publishing app to make a more practical handout for you guys… after all the post-digital age is upon us and a nice printed reference that you can flick through really is nothing to be ashamed of anymore. Also most tablets can open PDF files, for all the normies that are still stuck in the digital age. :smiley:

What really cracks me up though is that file doesn’t even do anything… must be a hoot, your teach!

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even though I agree and was tempted to post something similar, it’s still ridiculous that this file is so slow on the mac. Even if I cut-and-pasted part of it to a new file, the cutting went fast but pasting was very very slow on the mac. Maybe it is related to the text items that those slow down the mac considerably?

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I agree! Maybe somebody from dev team should investigate.

Actually, the teacher offered to separate notes and split components among different files, which did mitigate the problem, but we still have a serious performance issue here that remains unsolved.

Hi - I have put RH-56920 on the list of the developer to take a look.


I don’t think it’s as simple as: is Grasshopper/Rhino slow.

With Macbook “Pros” having a paltry 95-watt thermal/power scheme, iMacs not having the best cooling, and with the new Mac Pro, being quite expensive for their performance, it seems like Apple wants its computers to be designed on Windows computers.

Perhaps it would help to complain to the Apple store that their notebooks need a little kick in the keester. A great many gaming and “Mobile Workstation” computers are faster than a Macbook Pro.

Both computers have contemporary CPU, GPU, and memory. One can throw 200 watts of power at the magic-shape drawing problem, and the other less than 100. In the end, there’s no magic, just brute force, and cooling.

[ I was surprised to learn that a 18-core $7,999.00 Mac Pro rig barely edges out an AMD 3900x rig on Cinebench on multi-core, and looses to the 3900x on single-core. Such a machine can be made from parts for around $2500, likely with a RTX 1080. For another $250, you would have 4 more cores for rendering. If you get crazy with the money and let the price slide all the way up to half of the price of the Mac Pro, you can upgrade the aforementioned build with a RTX-2080ti.


At $2,355.13 for the Intel W-3245 and for $490 for the AMD 3900x, Intel should be worried. I am a fan–of competition, so I hope Intel gets their 7nm stuff together, just in a little while longer. ]

I believe this is accurate. See here:

“ 1. Processors are tricky, so pay attention. It is important that you get as much bang for your buck as possible since computational speed is often a bottleneck. But remember that Grasshopper and (most of) Rhino are single-threaded applications and therefore do not benefit from multiple cores. Do not be bamboozled by advertised processor speeds as those speeds may be given as a sum-total over all cores. I.e. an 8 core processor that has a total clock-rate of 6GHz will only give you 6/8 = 0.75GHz per core. If all you care about is Rhino and Grasshopper, you’d be better off getting a dual core @ 2GHz or even a single core at 1.8GHz”*

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I don’t think this is a wattage/CPU issue here…

Here is my experience:

Ran the .gh-file from above on my base model MacBook Pro 16" in macOS and got 31 seconds.
Then rebooted with Windows and ran the same thing: around 1 second.
in both cases the MBP was not plugged in btw.

So I think this shows, that this is not a CPU issue (I am not a computer scientist though, so I could be wrong.)

Also I do think, that the newest MBP 16" offers a pretty good value for its price (comparing it to a similar Windows machine - Lenovo X1 Extreme for example) … but this is another topic probably.


Any chance the Mac OS is switching to the intel graphics card with gh / rhino? On Windows the intel doesn’t ever get used as windows doesn’t have the dynamic switching. It should switch automatically to the high performance Radeon card per application requirements but there is also a way to force it.

I reported this issue to the Apple Forum. They told me to do some cleaning, which I did, but the speed to open the file is the same as before.

Just tried disabling automatic GPU Switching but it didn’t change anything. I think this must be a bug in grasshopper for Mac.

While much of Rhino is single-threaded, lately, some of the fastest single-core performance can now be found in chips with a higher core count than what we had in the past.

For example, even my aging, 4-year old 4800qm CPU’ed laptop can run all 4 cores at 2.7ghz. If only program only uses a single-core for an operation, it will likely “turbo” at 3.70 ghz. If you process is using two cores, it may be somewhere between, or it may throttle.

Lately, notebook processors are listed only by their “turbo” or single-core speed, as in “up to 3.5Ghz.” Ultimately, how long a chip can run at that speed has a lot to do with thermals, but there is a limit to how much heat can leave the CPU package, to the heatsink/heatpipe/fans.

Outside of Mac sphere of influence, most many people rely on Cinebench, but it would make sense that Holomark should be a good test for Rhino performance.

The thing that’s upsetting is: lately, it’s been harder to find fast quads in notebook computers. Given how poorly modern laptops generally cool themselves, once you start rendering something in Rhino’s renderer or Cycles, or any other raytracer, they throttle.

I think that the computer that designs has a rougher time than even a gaming computer, as far as heat.
People are still building computers for design for a bursty workload, which isn’t the way things are now, with Cycles, or even Revit. In a generally sense, people are designing notebook computers that can either use a lot of CPU or a lot of GPU, but too often, they throttle badly on each.

Not all of Rhino is single cored. Meshing on load seems to hit all the cores. AFAIK, some grasshopper widgets take advantage of multiple threads, and are marked as such.