Does adding cpu cores really make much difference if not rendering with them?

[Paul King]

I have a PC with an old 4 core 8 thread i7 4790K CPU, 32 GB RAM, M.2 drive SSD, and GTX980Ti GPUs.

I have been considering an upgrade to something that can handle more CPU threads, in the hope that ArchiCAD23/24 will become more responsive on complex hi poly count , multiple hotlinks etc projects.

I am a freelancer and generally have to work with projects as I find them - model structure and efficiency are often out of my hands, and I tend to have to follow whatever 'lowest common denominator' office standards are already in play when I am brought in.

I am also at the mercy of whatever imported structural and services IFC models are produced when attempting to coordinate (generally no fancy BIMcloud services on tap - just old fashioned manual IFC file exchanges via DropBox). Switching one or two of these on I find can bring any ArchiCAD session to its knees, particularly if the engineer responsible has not been very good with separating things into useful layers, meaning every bolt has to be shown when beams are switched on, and when everything appears on a single story etc.

Obviously am also impacted by whatever remote Bimserver and VPN folder structures setup I need to dial in to but appreciate more CPU cores won't help with this one.

Sometimes I need to have more than one such project open at the same time. As well as maybe a session or two for hotlinked modules being edited, the normal Email, PDF viewer and browser windows open (generally not too demanding in themselves)

Other than model efficiency, the only variable I do have much control over is my own hardware.

I don't use CPU rendering at all - all GPU based.

All things being equal, am I likely to notice much day to day benefit while wrangling large cumbersome models by switching to something with 10-12 CPU cores? Jumping between views, loading 3D geometry into GPU etc. Would more than 12 make a lot of difference? (where do diminishing returns kick in)

Any benefit at all in moving to a PCIe 4 bus, with all that data needing to be shunted between harddrive and GPU?

Any tips most welcome.

[Lingwisyer]

You could log your current computers CPU and RAM utilisation over a couple of days to see where your primary bottlenecks are. This can be done through Windows Performance Monitor.



Ling.

[Paul King]

Lingwisyer wrote:
You could log your current computers CPU and RAM utilisation over a couple of days to see where your primary bottlenecks are. This can be done through Windows Performance Monitor.

Hi, thanks for that.

Yes, I have noticed that RAM is not ever an issue in my case, but CPU utilization bumps into 100% when generating 3D views or large sections or elevations, but I also see something like 100 - 200 threads are allocated to each ArchiCAD session open

What I am not able to identify is how many of those threads are dormant at any given time vs how many are responsible for pushing overall CPU utilization to 100% during view generation - it could just be one or two threads being allocated all the work for all I can tell, suggesting additional cores may not help.

[Erwin Edel]

The examples of poor drafting seem to be mostly impacted by GPU, also in 2D plan view (redraw time).

CPU might come into play with mutliple tabs and having to regenerate.

I once had to deal with a 3rd party project where all the 2D details were on one giant worksheet and contained many, many, MANY exploded DWG files with loads of double lines etc. These were then placed as individual drawings (resized) on layout. However updating one of these layouts would mean updating the entire worksheet and that took forever.

You could hotlink the IFC export from a PLN where you fix most of the poor drafting/layers and keep importing to that seperate PLN to keep your master file clean.

Sadly, I think going through the junk of the 3rd party and cleaning it up is sometimes the best time spent v.s. time lost on updates. In the above example I purged the entire worksheet of all the double elements and split the worksheet up in to two or three seperate ones to keep the amount of 2D elements per view low enough for speedy redraw/regeneration.

I do notice Xeon processors deal better with Cinerender than i7 processors, but I've not noticed a huge difference on 2D work. The 3D window navigation seems entirely tied to the GPU.

Given the by now old hardware of my HP workstation and it still handling ArchiCAD projects well enough, I think it's more to do with the poor skills than lack of power on your setup (which seems more than adequate even for large projects).

[Paul King]

Thanks Erwin
An excuse to buy an RTX3080 maybe? (to future proof myself for ArchiCAD 35)

[Lingwisyer]

If you can get past all of the scalpers sniping the cards...

[Paul King]

Lingwisyer wrote:
If you can get past all of the scalpers sniping the cards...

Yeah. And even the 'honest' local retailers here in New Zealand are throwing a few hundred dollars on top of the recommended retail price I see.

[Erwin Edel]

I'm not 100% sure about this (as in no real testing / proof), but my old Quadro K2000 seems better equiped at 2D redraw than the newer 'gaming' mobile cards in my 2013 iMAC at home and the macbook pro machines we also have at the office. In 3D window it seems reversed.

I do like the robustness and quality of the Quadro hardware and the drivers are a breeze to update, when I feel like updating.

[Paul King]

Erwin wrote:
I'm not 100% sure about this (as in no real testing / proof), but my old Quadro K2000 seems better equiped at 2D redraw than the newer 'gaming' mobile cards in my 2013 iMAC at home and the macbook pro machines we also have at the office. In 3D window it seems reversed.

I do like the robustness and quality of the Quadro hardware and the drivers are a breeze to update, when I feel like updating.

From what I have experienced (again no real empirical testing to quote) if money is no object, the very best 2D performance probably does come from the best Quadro, but where there is a limited budget, the best performance seems to come from the best consumer Gforce card that same budget will buy - simply because with any any given Quadro you could buy with a given budget, the same budget will buy a Gforce card that is a generation or two newer and faster, and with more memory. And of course driver development is more active for consumer cards (new driver not always for the better with either Quadro or Gforce, but at least with Gforce, there are usually more recent roll back options)

Certainly I recall the odd issue with Quadro cards when using them under AC17 and 18 that went away after dropping in a newer GForce card as a replacement. I think most of the time you are generally fine with any recent card now, but very large projects may test this, especially when using trace reference a lot in addition to complex hotlinked IFC's etc. Although I notice CPU usage and disk writes both spiking when panning and zooming around and editing in demanding views - not sure if this represents a GPU bottleneck or not. The disk writing might be somewhat explained by data safety set to 'save every step'

[Nader Belal]

@Paul King

The i7 4790k is getting a little bit outdated in general, and for the model size and complexity that you imply is starting to show its age. But again, may be there is something that is within your model that is causing this lag.

So I would advise:
1. Try to open your model on another PC with a higher core count such as AMD Ryzen 7 1700 and up.

2. Make a copy of your project, and start deleting things, such as layout, models, etc.

That way you would have a more precise idea on what is causing such lag.

PS:

• I didn't know if you're working on MAC or PC, but anyway, check the OS updates.
• If you want to buy new hardware, just wait 2-3 weeks, AMD will release the new CPU Ryzen and Radeon GPU, and the competition is getting hot, and that my push the prices down