MSFS & Hyperthreading

[iFlySimX 773]

Hello all! 

I decided to do some testing with my i9-9900k as I've been getting some stutters on the ground with the Fenix A320. 

I turned Hyperthreading OFF in the BIOS and it seems a lot smoother and gives me higher FPS. Is that expected, any reason why I SHOULDN'T keep Hyperthreading off?

Edited December 7, 2023 by iFlySimX

[Bert Pieke 7,610]

39 minutes ago, iFlySimX said:

I turned Hyperthreading OFF in the BIOS and it seems a lot smoother and gives me higher FPS. Is that expected, any reason why I SHOULDN'T keep Hyperthreading off

You have a lot of cores in that CPU, so I am not surprised.. On my quad core CPU on the other hand.. HT is pretty useful.

[iFlySimX 773]

4 minutes ago, Bert Pieke said:

You have a lot of cores in that CPU, so I am not surprised.. On my quad core CPU on the other hand.. HT is pretty useful.

[Bert Pieke 7,610]

2 minutes ago, iFlySimX said:

Yup.. you have 8 real cores... I have 4..

[ZKOKQ 986]

46 minutes ago, Bert Pieke said:

Yup.. you have 8 real cores... I have 4..

Mine is 6 Bert, would I benefit from HT ?

[Bert Pieke 7,610]

30 minutes ago, ZKOKQ said:

Mine is 6 Bert, would I benefit from HT ?

Not sure there is a hard and fast rule... so I'd say: test it and see!

On my quad core, HT provides a benefit.. on the above system, the opposite..

On yours....?   Maybe 50/50?   Let us know!  🙂

[Alvega 2,127]

20 minutes ago, Bert Pieke said:

On my quad core, HT provides a benefit

Same here, also quad core (i7 4790K).

[iFlySimX 773]

2 hours ago, Bert Pieke said:

You have a lot of cores in that CPU, so I am not surprised.. On my quad core CPU on the other hand.. HT is pretty useful.

 

So why would I benefit more with HT off if I have more cores?

 

 

[ZKOKQ 986]

1 hour ago, Bert Pieke said:

Let us know!

Will do

[Bert Pieke 7,610]

1 hour ago, iFlySimX said:

 

So why would I benefit more with HT off if I have more cores?

 

 

MSFS will use all the cores that you have available..  With HT on, that is 16 cores (which share 8 real cores, two for one).  8 real cores is enough to get the job done, and 16 can become "too many cooks in the kitchen"..

[GSalden 4,726]

2 hours ago, Bert Pieke said:

MSFS will use all the cores that you have available..  With HT on, that is 16 cores (which share 8 real cores, two for one).  8 real cores is enough to get the job done, and 16 can become "too many cooks in the kitchen"..

Will check my CPU’s. Good to see a thread like this.

[MrFuzzy 2,132]

7 hours ago, iFlySimX said:

Hello all! 

I decided to do some testing with my i9-9900k as I've been getting some stutters on the ground with the Fenix A320. 

I turned Hyperthreading OFF in the BIOS and it seems a lot smoother and gives me higher FPS. Is that expected, any reason why I SHOULDN'T keep Hyperthreading off?

How did you get these numbers? Are the testing environment and the results reproducible?

[Nemo 1,308]

Interesting topic. With a 13900k with 8 Performance Cores (16 threads wit HT on) I could disable HT I guess. But what about the remaining (active) 16 Efficiency Cores. Should I disable them too?

 

[SierraDelta 1,371]

20 minutes ago, Nemo said:

Interesting topic. With a 13900k with 8 Performance Cores (16 threads wit HT on) I could disable HT I guess. But what about the remaining (active) 16 Efficiency Cores. Should I disable them too?

 

Same processor as you. I run with HT Off and 8 Efficiency cores, so 8+8. MSFS runs brilliantly, temp is around 60 celsius.

[Rocky_53 1,613]

Ah, to Hyperthread or to not Hyperthread, that is the question! This old chestnut has been around so often in FSX and P3d that I had totally forgotten about it in MSFS  I certainly used to find a much smoother sim running P3d with HT off. I will do some tests in MSFS and see how I get on.

Edited December 8, 2023 by Rockliffe