F-4 multi-thread performance expected performance question: threads vs cache?

[Voyager]

Reading the recent March 16th update, and noticed the mention that the F-4 is fully multi-threaded.

With all the new CPU architectures being released or on the horizon, I was wondering if there was a good idea of which sort of layout would play best with the F-4?

Is the module expected to run better with a high thread count, or would a 7800X3D or Zen 5 X3D be expected to run better, even with only 8 cores, 16 threads? 

Have a 5800X3D which has been keeping up, but thinking about rebuilding my PC's backbone after Zen 5 releases, so wondering how things are architected. 

Thank you, 

Harry Voyager

Edited March 17, 2024 by Voyager
Hello typos, my old friend, I am come to talk with you again...

[Raven (Elysian Angel)]

I think it was SkateZilla who mentioned quite a while ago that  DCS works particularly well with V-cache CPUs.

[Hiob]

8 Cores are sufficiant. V-cache is more useful than further cores. 

7800X3D is probably the single best suited cpu for DCS right now.

[Johnny Dioxin]

Yeah, it's funny - my 7800X3D is always shown as the limiting factor in my DCS performance! With a 4080 and 64GB of DDR5. Mind you, that doesn't mean the performance is bad, far from it - it's just the limiting factor

I've been getting a lot of 90fps averages of late - though it does occasionally drop to 45 for a short while when there's lots of AI about. Doesn't stop the occasional bout of low-altitude stutters when looking at the terrain, though. I'll have to get the frametimes noted - my favourite performance monitor (fpsVR) doesn't seem to work in OpenXR for some reason.

[Hiob]

3 minutes ago, Johnny Dioxin said:

Yeah, it's funny - my 7800X3D is always shown as the limiting factor in my DCS performance! With a 4080 and 64GB of DDR5. Mind you, that doesn't mean the performance is bad, far from it - it's just the limiting factor

I've been getting a lot of 90fps averages of late - though it does occasionally drop to 45 for a short while when there's lots of AI about. Doesn't stop the occasional bout of low-altitude stutters when looking at the terrain, though. I'll have to get the frametimes noted - my favourite performance monitor (fpsVR) doesn't seem to work in OpenXR for some reason.

DCS doesn't take perfect advantage of multithreading right now. As they stated themselves, they only took the first steps so far. The current VR implementation takes an extra toll on the cpu. Even more important, that every single core is as performant as possible, which 3D-Cache does help a lot with.

I bet, when you're cpu-bound, only two cores/threads are really at 100% - so having a 12 or 16 core cpu wouldn't help.

When you're  continously cpu bottlenecked, I would recommend dialing up the GFX-settings. 

[Raven (Elysian Angel)]

6 hours ago, Johnny Dioxin said:

my 7800X3D is always shown as the limiting factor in my DCS performance

Keep in mind that even though it may be reported that your system is "CPU limited", you can be engine-limited instead.

[Hiob]

29 minutes ago, Raven (Elysian Angel) said:

Keep in mind that even though it may be reported that your system is "CPU limited", you can be engine-limited instead.

What do you mean by engine-limited? In the sense that the game engine is limited to one main render thread (maybe two in VR) - yes, that‘s a limiting factor of course. But other than that, every additional effective clock or IPC will directly translate to more fps. Until you are GPU-limited of course, or any other bottleneck, like read/write operations or so are happening.

Edit, typos.

Edited March 21, 2024 by Hiob

[Tiger-II]

On 3/21/2024 at 8:30 PM, Hiob said:

What do you mean by engine-limited? In the sense that the game engine is limited to one main render thread (maybe two in VR) - yes, that‘s a limiting factor of course. But other than that, every additional effective clock or IPC will directly translate to more fps. Until you are GPU-limited of course, or any other bottleneck, like read/write operations or so are happening.

Edit, typos.

 

That's largely rubbish.

What @Raven (Elysian Angel)wrote was the engine can't run faster even if your CPU had twice as many cores and twice the clock speed. THAT is what "engine limited" means. It will appear as "CPU limited" in performance apps, because it means the rest of the system has cycles to spare waiting.

[Hiob]

6 hours ago, Tiger-II said:

That's largely rubbish.

What @Raven (Elysian Angel)wrote was the engine can't run faster even if your CPU had twice as many cores and twice the clock speed. THAT is what "engine limited" means. It will appear as "CPU limited" in performance apps, because it means the rest of the system has cycles to spare waiting.

There is now such thing as engine limited currently in DCS (unless you set the fps limiter of course).

DCS will happily run at 240 fps if cpu and gpu allow for it.

DCS (when not GPU limited) scales almost linear with cpu clock speed.

Well, adjusted for other benefitial factors like cache of course.