Is Unity 5 a very multi threaded application?

[DeadlyPilot]

 

Tried posting this on Unity's site but their forums are dead and useless..

 

Say I wanna build a PC for the sole purpose of developing on Unity. How many cores will Unity utilize? Would I want to buy a CPU with better single thread or multi thread performance? I don't mean the amount of threads my games can be written to use, but the Unity Editor itself. Say I want the best performance when working on projects.

[ARikozuM]

Unity is single-threaded and multi-threaded and how many cores it uses is dependent on your programming and parameters. Most of the physics inside of Unity are still single-threaded. 

[Zando_]

1 minute ago, ARikozuM said:

Unity is single-threaded and multi-threaded and how many cores it uses is dependent on your programming and parameters. Most of the physics inside of Unity are still single-threaded. 

Then I'd go for an i7, since they generally have a high clock, good for single core tasks, but still have 8 threads for multithreaded workloads. 

[ARikozuM]

9 minutes ago, Zando Bob said:

Then I'd go for an i7, since they generally have a high clock, good for single core tasks, but still have 8 threads for multithreaded workloads. 

For development, I would suggest a Ryzen octacore so that he can test and debug in real-time without bogging the system down. 

 

@DeadlyPilot Make a build with an i7 hexacore and an R7-1700 and see which offers the most for the money. 

[Zando_]

4 minutes ago, ARikozuM said:

For development, I would suggest a Ryzen octacore so that he can test and debug in real-time without bogging the system down. 

 

@DeadlyPilot Make a build with an i7 hexacore and an R7-1700 and see which offers the most for the money. 

Though if he's doing a lot of single-core work, the i7 7700K is much faster than an R7 1700. Though the Ryzen is a lot more bang for the buck and will still fly through almost any task.

[zwirek2201]

You can overclock an i7 7700K to about 4.8 - 5.0 gHz (if you're lucky). You can overclock Ryzen 7 1700 to about 3.8 (and even 4.0) gHz and it's cheaper and has 4 more cores. I think 4 more cores of Ryzen 7 will give you larger performance boost than 1gHz more on the i7 7700K.

[DeadlyPilot]

9 hours ago, DeadlyPilot said:

 

 

9 hours ago, ARikozuM said:

Unity is single-threaded and multi-threaded and how many cores it uses is dependent on your programming and parameters. Most of the physics inside of Unity are still single-threaded. 

I'm a bit confused. So the games that I write in Unity can use as many threads as I optimize them to, but as far as the editor itself when developing and debugging games, it uses more than a single thread right?

[ARikozuM]

11 minutes ago, DeadlyPilot said:

 

I'm a bit confused. So the games that I write in Unity can use as many threads as I optimize them to, but as far as the editor itself when developing and debugging games, it uses more than a single thread right?

Single-thread doesn't mean that it uses one core. Battlefield 1 uses multiple cores, right? 

Does that mean that it's a multi-threaded application? NO!

 

BF1 has a lot more single-threaded functions as opposed to multi-threaded, but can offset them among many cores. A single-threaded task cannot be shared between cores and HT/SMT only schedules the 2nd task for when the 1st is complete. Multi-threaded functions are split into pieces as they may not rely on incredibly precise calculations or can be done in pieces allowing them to later be approximated. You can assign a number of cores to your program, but you won't be able to make it wholly single-threaded unless you want a bullet hitting something behind a wall because Core 2 didn't complete the wall penetration calculation fast enough or you want bullets that decide "coffee breaks" are entirely appropriate in mid-air by utilizing a pause parameter so that Core 2 can finish and send its work to the master core. 

 

TL;DR: Leveraging multiple cores does not make an engine multi-threaded. HT/SMT do not add more cores to your system since they themselves don't perform calculations but rather hold them. 

[DeadlyPilot]

2 minutes ago, ARikozuM said:

Single-thread doesn't mean that it uses one core. Battlefield 1 uses multiple cores, right? 

Does that mean that it's a multi-threaded application? NO!

 

BF1 has a lot more single-threaded functions as opposed to multi-threaded, but can offset them among many cores. A single-threaded task cannot be shared between cores and HT/SMT only schedules the 2nd task for when the 1st is complete. Multi-threaded functions are split into pieces as they may not rely on incredibly precise calculations or can be done in pieces allowing them to later be approximated. You can assign a number of cores to your program, but you won't be able to make it wholly single-threaded unless you want a bullet hitting something behind a wall because Core 2 didn't complete the wall penetration calculation fast enough or you want bullets that decide "coffee breaks" are entirely appropriate in mid-air by utilizing a pause parameter so that Core 2 can finish and send its work to the master core. 

 

TL;DR: Leveraging multiple cores does not make an engine multi-threaded. HT/SMT do not add more cores to your system since they themselves don't perform calculations but rather hold them. 

Right, just cause it can use multiple threads doesn't mean it will fully utilize each and every one. I'm just wondering up to how many threads the Unity 5 editor will fully utilize, not so much how many threads my games themselves will fully utilize. 

 

Also, your basically saying HT and multi threading basically prepares one task to be calculated after the one ahead finishes? How is this faster than a single thread on each core?

[aithos]

Software development can be either slightly threaded or heavily threaded depending on what you're doing specifically.  I can't speak for Unity, but Unreal Engine has a lot going on and having additional cores/threads AND higher clock speeds is definitely a benefit.  Also, keep in mind that if you're going to do any kind of art (3D rendering/modeling) or any kind of virtualization that having good multi-threaded performance is going to be a huge benefit.

 

Bare minimum you'll want a decent i7 and it may be worth considering Ryzen as well.  I definitely prefer Intel for my rigs since I mostly game at home and develop at work, but this is one of the cases when team Red having the better threaded performance for a decent price is worth looking at.

[Mira Yurizaki]

One thing I want to add, while you should develop on a high-end system, you should test on the lowest possible configuration you'll be allowing.

[ARikozuM]

@DeadlyPilot My Android cut half of my response out.

 

HT schedules a thread/function for faster access once the first function is done. HT doesn't do any calculations itself.

 

The Editor itself uses every core you can likely throw at it. Obviously, you shouldn't overspend on a 20-core CPU if you're dropping frequency for those cores. I would look into an octacore from the Ryzen line-up since they can offer you as many cores as you'd like without dropping frequency like an anchor.

[Mira Yurizaki]

On 6/19/2017 at 6:09 PM, DeadlyPilot said:

Also, your basically saying HT and multi threading basically prepares one task to be calculated after the one ahead finishes? How is this faster than a single thread on each core?

HyperThreading enables a single core to allow another thread to use unused execution resources if the one its working on doesn't use them. For example, if one thread needs only the integer ALU for its work, another thread that only needs the FPU can be executed on the core at the same time.

 

Or to put it in another way, say you're working on some craft project that involves cutting and gluing. However, there's only enough scissors and glue to go around for two people to have one of each. So you pair up. But chances are you both won't be needing the scissors or the glue at the same time, so while one cuts, the other glues.

[PocketNerd]

It's funny how you're all answering the wrong question.

OP, the Editor itself should be ok to run on a 4-core system, with or without HT/MT. Compiling code is a bit of a different story, where the more cores/threads the better. I'd focus more on utilizing a SSD to load projects.

[JoseGuya]

Two recommendations for working with Unity: 

 

Get a big SSD, really, loading and compiling a project benefits greatly from this. 

 

Go for the best CPU you can afford. Again, compiling all the assets and scripts benefit greatly from a multi core cpu. 

 

source: Me, working with Unity for VR projects in the last year and a half. 

[mathijs727]

On 6/20/2017 at 3:01 AM, ARikozuM said:

Single-thread doesn't mean that it uses one core. Battlefield 1 uses multiple cores, right? 

Does that mean that it's a multi-threaded application? NO!

 

BF1 has a lot more single-threaded functions as opposed to multi-threaded, but can offset them among many cores. A single-threaded task cannot be shared between cores and HT/SMT only schedules the 2nd task for when the 1st is complete. Multi-threaded functions are split into pieces as they may not rely on incredibly precise calculations or can be done in pieces allowing them to later be approximated. You can assign a number of cores to your program, but you won't be able to make it wholly single-threaded unless you want a bullet hitting something behind a wall because Core 2 didn't complete the wall penetration calculation fast enough or you want bullets that decide "coffee breaks" are entirely appropriate in mid-air by utilizing a pause parameter so that Core 2 can finish and send its work to the master core. 

 

TL;DR: Leveraging multiple cores does not make an engine multi-threaded. HT/SMT do not add more cores to your system since they themselves don't perform calculations but rather hold them. 

I do not agree with you, especially your BF1 example.

Frostbite, like most engines these days (see GDC presentations of Naughty Dog and Bungie), uses a task/job graph to schedule tasks over multiple cores.

The task system launches a bunch of threads at the start of the program, after which they use an internal taks system to schedule jobs (usually using function pointers although Naughty Dog uses fibers (cool stuff)).

They do this because creating and closing threads has a relatively high overhead (creating/closing threads takes "a lot of" time).

 

This is certainly multi-threading (multiple tasks are executed in parallel).

 

Also, like Yurizaki said, hyper threading introduces extra  "helper" cores which can use unused execution resources.

So they do execute their work in parallel with the "main" cores.

[Guest]

Unity says it depends on your workload. 

Ive used unity on a 16 or 24 thread xeon with 32 gb of ram of which the system ran beautifully I cannot say how many cored it utilized however I've seen people develop on laptop i5s and even surface tablets. The biggest concern id have is 8gb or 16 gb of ram. On my dual thread laptop i7 3000 series I was doing exceptonally well in 3D. I made an FPS game with up to 7 animated AI running and shooting projectiles running really well in development on all sorts of systems with custom assets in 100^2 unit environments using the editor. 

 

If youre just building a PC to start game development, build a gaming pc and you'll be plenty fine. My i5 3450 is more than enough with 4 threads. 

 

For a pc recommendation, 

i5/ryzen 5 or better

6 gb of ram or better

integrated graphics minimum, 750 ti or better

plenty of HDD space for projects. 

 

Have you had ACTUAL problems on your current pc? If so try opening unity again and see what's slow after the editor and script editor are open. 

 

If you have a 64 bit system make sure you have 64 bit OS and 64 bit Unity. It works beautifully on the big 3. (Windows(8 and 10 personally tested), Mac(i5 2013 iMac model personally tested), Linux-Ubuntu and Lubuntu personally tested.)