which CPU is best for AC?

[Tim Meuris]

I mean how many cores does it need to play this game best
and ARMA 3 as well (on 3 screens)

sorry bit of a noob in this area
so I hope i asked the right question...

 

[Bokonon]

I see what you mean about threads as opposed to cores, there are no games as far as I know that really make use of Hyperthreading (i7s etc), that is most useful for video encoding etc. I think that a modern quad core should suffice for this game.
I did the same race at Silverstone the 24 lotus's with a clock of 4.2GHz and there was a noticable improvement in framerates, 60-90 on average droping briefly to 30 ish when there was a lot of smoke coming from tyres at the start. CPU usage was between 50-80% across all cores, at one point core 2 went to 88% for a brief moment. There were no Occupany warnings as I got yesterday(brief though they were) at 3.3Ghz (stock speed for the i5 2500k).
If anyone is interested I would be willing to do a more scientific comparison of my overclock results.

 

[Paul Lock]

Turning HT off lost me an average of 10 fps across a variety of my tests graphics/ ai combos. It definitely makes a difference but it is clear to see the additional threads are not being used to the best of their abilities when viewing activity in CPUid / perf monitor.

Also this behaviour does affect the 'overall' usage figures you might see in task manager, because although your CPU is choking, a couple of your 8 threads generally arent doing anything, so the combined monitor thinks you have more headroom than you actually have.

Most mainstream games are console ports so would never make use of HT hence why i5s have been the sweet spot recently bang for buck wise, no real advantage with i7 HT.
When Kunos work this out (which they will) there should be a tangible advantage for HT chips.

 

[Stereo]

Process Explorer can show you more detailed info on threads.

(6-core AMD cpu, running 11 car grid at Magione with the Abarth 500)

I think you would see acs.exe showing up several times if it was running physics or something multithreaded.

nv-stuff is the display drivers, WINMM and Xaudio are audio drivers, WmJoyF32 is controller driver. Nothing else even seems to use CPU time really.


I was surprised to see that audio is using nearly as much CPU time as physics or graphics...

 

[Tjaž Brelih]

Audio manipulation can be quite an expensive thing. For example, distant sounds aren't just quieter, but they should also be "darker" (less middle and high frequencies), which means that audio should be processed with some sort of equalizer, and the "severity" of the effect should be proportional to the distance from the listener to the source.

For now, all those calculations have to be done by the CPU, but AMD has announced, that they'll start to equip their graphic cards with sound processors (TrueAudio), and I'm quite excited about this, since not only will we get a better audio experience, but the CPU won't have to deal with audio anymore.

 

[Kris Migut]

On my Core i3 3220 @3,5 Ghz, GTX650 Ti and 8 GB RAM I find AC running very well most of the time, even with 22-24 AI cars. True, I get the >95% warning almost all the time, but with 50-70 FPS it doesn't really bother me. With 18 AI cars the warning does not appear at all, so in my case 18 cars seems to be the limit - but still I pick 22-24 cars to race against as my PC is apparently able to handle that, it must be a bit sweaty, though .

Only once did I get a massive slowdown, when some AI cars caused a huge collision after Lesmo 2 at Monza; I registered between 5 and 7 FPS then, but I assume it was an optimisation glitch of some sort, soon to be rectified.

 

[Pedro Cunha]

On my Core i3 3220 @3,5 Ghz, GTX650 Ti and 8 GB RAM I find AC running very well most of the time, even with 22-24 AI cars. True, I get the >95% warning almost all the time, but with 50-70 FPS it doesn't really bother me. With 18 AI cars the warning does not appear at all, so in my case 18 cars seems to be the limit - but still I pick 22-24 cars to race against as my PC is apparently able to handle that, it must be a bit sweaty, though .

Only once did I get a massive slowdown, when some AI cars caused a huge collision after Lesmo 2 at Monza; I registered between 5 and 7 FPS then, but I assume it was an optimisation glitch of some sort, soon to be rectified.

Here everything maxed out and I never went below 40fps with 24 Cars at worst collision scenarios. (including replays) i74770K 4.8ghz /Titan SLI.
But yes, game needs CPU optimization.

 

[Justin Swan]

Here everything maxed out and I never went below 40fps with 24 Cars at worst collision scenarios. (including replays) i74770K 4.8ghz /Titan SLI.
But yes, game needs CPU optimization.

With 2 Titans in SLi, I'd want to see 400 fps at worst for that kind of money

 

[Simon Roberts]

Here everything maxed out and I never went below 40fps with 24 Cars at worst collision scenarios. (including replays) i74770K 4.8ghz /Titan SLI.
But yes, game needs CPU optimization.

Something really doesnt seem right with your rig! I can maintain 60fps on a single 780 and triples.

 

[Pedro Cunha]

With 2 Titans in SLi, I'd want to see 400 fps at worst for that kind of money

Like i said, it's Assetto Corsa issue.

 

[Pedro Cunha]

Something really doesnt seem right with your rig! I can maintain 60fps on a single 780 and triples.

No, you can't. With full grid no one can stay above 60fps with the game maxed out.

 

[vegaguy5555]

Sorry to bump such an old thread but since I can't get a better GPU and it really is time for some faster ram. What is the best CPU for AC or does "the most you can afford" still apply?

 

[Johnr777]

Sorry to bump such an old thread but since I can't get a better GPU and it really is time for some faster ram. What is the best CPU for AC or does "the most you can afford" still apply?

Faster RAM wont get you out of your FPS troubles....

But if you are upgrading... I heard Ryzen's tend to outperform intel's. And the game favors higher single core speed over number of cores...

But you might not see much of an improvement since you are GPU bottlenecked.

 

[Lizard Of Bodom]

FWIW, I have Ryzen x3700 and most I ever saw was 25% CPU usage in heaviest possible tracks (LAC with 40 users) so this game still prefers CPU speed over core count, however these days to futureproof yourself I would go for 8core/16thread CPU based on fact that all current gen consoles have 8cores and games may start utilising them soon.

 

[vegaguy5555]

That may explain my 4 core 4790k at a 100% once in a while?

 

[McGherkin]

I've just gone from a 4690k to a Ryzen 5800x and my thoughts are as follows.

If you've just got a couple of cars (well up to 15-20) on track then you're not going to notice much of a difference going from something like a 4690k because you're likely going to be GPU limited by then (I could play at 4k120 just fine with a 3070 and the 4690k)

If you're weird like me and REALLY want to fill every grid slot at Le Mans or LAC etc then the difference is night and day - 56 cars on track and only 25% CPU utilisation - AI in Assetto is multithreaded, so big grids will benefit massively from more cores but at the same time the main thread is pretty busy and that needs speed as well.

I think for anything short of running like 100 cars a 3600x or similar is going to be enough for Assetto, to be honest.

 

[vegaguy5555]

I've heard Ryzen come up a few times now!
AC a good fit with Ryzen CPU's?

 

[RasmusP]

When you download and run process explorer, you can go into the details of the ac application and see the application threads.
You'll see 2 big ones, hitting the single thread limit, one thread being about 50% of the other 2 and then a lot of very small threads.

One thread can use one cpu core at one moment in time.
So with a 6c/12t cpu like my 10600k or a Ryzen 3600/5600, the calculation is:
100% divided by 12 = 8.33% maximum for one single application thread.

So in theory you would have 2x 8.33% plus 1x 4.16% plus a few little ones.
= 20-30% overall cpu load.

However Windows throws all threads around all cpu cores/threads all the time so you see an average load in Taskmanager and other tools.
You probably see no core at more than 50% and you'd think your cpu would have plenty of headroom.
But it has none. It's hitting the single thread performance limit!

I did a lot of benchmarking and you won't gain anything with more than 5 physical cores.
And beyond 5 physical cores, HT or SMT won't give you more fps either.

With only 4 physical cpu cores, ac + background processes will occasionally max out the cpu though!


Anyway my point:
Get a cpu with at least 5 physical cores and then go for the absolute maximum in single core performance.
That means newest generation and highest clockspeeds.

With Intel, you can basically overclock any K CPU to 5 GHz.
Which also means you won't see much difference between a 8700k,9600k,9700k,9900k,10600k,10700k,10900k etc.

You will gain a few single fps due to the 10900k for example boosting to 5.3 ghz and having a bigger cache.
But it's maybe 100 fps to 107 fps for 3x the price!

For AMD, the 3xxx series was "okay" for simracing but the 5xxx series has higher single core performance than the 10th Gen Intel!

11th Gen Intel is a game depending mixed bag.. It has some core to core latency issues so depending on the application, you will get higher or lower performance compared the the previous generations.


Recommendation:
AMD 5600x!!!

More cores are just wasted money. Sure, you get a few hundred mhz clock speeds but it's really not worth it.


Memory:
My acc benchmarking showed that timings are not as important as clock speed.

So I would recommend to get the highest speed you can get for as cheap as you can.
A good deal would be some 2x8GB 3600 cl18 for around 80€.

 

[Panthera]

Recommendation:
AMD 5600x!!!

More cores are just wasted money. Sure, you get a few hundred mhz clock speeds but it's really not worth it.

Thats's what I would recommend, too. With a break in 2004 I was always using Intel and in the last decade AMD wasn't playing a big role in the cpu market.

I've changed my mind again and I'm convienced how well an actual AMD can perform. Further the bang for the buck factor is very attractive. Better not to speak about the graphic cars atm...

 

[RasmusP]

Yep, AMD was just nowhere...
1xxx series was flash of what was to come. 2xxx series was very good bang for buck for modern games that could use 6 cores or more.
3xxx series was a direct competitor. A bit cheaper, more multicore performance, less single core performance. Great for overall gaming and in general but lacking the single core performance needed for our simracing titles.

5xxx series now blew Intel out of the water for simracing and the 11th Intel gen is just... a mixed bag and a poor try to keep up.

Btw about people saying "Get an 8 core CPU! The new consoles have 8 cores so titles will be optimized for that!".
Yeah.. no... The best future proofing with the current increase in single core performance gen after gen is to keep your money and save up for an AMD 6600x or 7600x or an Intel 12th/13th gen DDR5 build with new mobos and new sockets.