Hello,

I couldn't resist getting two more cores and I have decided to switch from i7-6700K to i7-8700K. I have made few benchmarks monitoring FPS rate through SimConnect (using my own tool).

 

My specs:
before: i7-6700K @ 4.7 GHz, MSI Z170A Tomahawk
after: i7-8700K @ 5 GHz, Asus TUF Z370 Pro Gaming

16GB RAM, Gigabyte GTX 1080 WF3, 512 GB SSD + 2TB HDD

As you can notice, the i7-8700K clock was running at slightly faster speed (+6%).

In VR test I had Oculus Tray tool with pixel density set at 1.5 and Oculus Dash 2.0.

 

Test case:
I have flown PMDG 737 on the same route from EPMO to EPWA through WAR at FL150.
For each setup I have performed 2 flights - one with regular monitor and another one with Oculus Rift in native VR mode.
I have been flying in exactly same, historical weather - 16th January 2018, 11:35 UTC with ASP4 and ASCA. Another addons include: FTX Global, Open LC Europe, Vector, Drzewiecki Warsaw X, Drzewiecki EPWA, FSGlobal Ultimate NG, Envtex + Envshade.
My graphical settings were medium with most of the settings slightly to the left, or in the middle.

 

Results (FPS):
1. i7-6700K @ 4.7 GHz (non VR)

average: 58.6
median: 57.6
st.dev.: 12.875

FPS chart:
https://image.ibb.co/hrA616/i7_6700k_1.jpg

2. i7-6700K @ 4.7 GHz (native VR)

average: 28.4
median: 23.1
st.dev.: 9.149

FPS chart:
https://image.ibb.co/dPOgZR/i7_6700k_vr.jpg

3. i7-8700K @ 5 GHz (non VR)

average: 62.1 (+6%)
median: 64.4 (+12%)
st.dev.: 11.082 (-14%)

FPS chart:
https://image.ibb.co/hWSEom/i7_8700k_2.jpg

4. i7-8700K @ 5 GHz (native VR)

average: 27.3 (-4%)
median: 23.2 (+0.4%)
st.dev.: 7.775 (-15%)

FPS chart:
https://image.ibb.co/i5Uuom/i7_8700k_vr2.jpg

 

Conclusion:
All six cores where running at 70-80%. GPU at same rate.
There is slight FPS gain in non-VR mode, but it could be explained with increased core speed. Suprisingly, there is no boost in VR mode.
However, what is worth notice is that standard deviation for i7-8700K is lower for around 2 fps (15%), and median is higher (12%) so it means we have more stable frame rate.

I have also noticed less bluries and faster textures and objects loading. I think that additional cores are used to process background tasks that load textures, objects and autogen. And that is confirmed with the quote from LM developer:

'The speed of the primary core will be the determining factor FPS assuming your settings have you CPU-bound. For raw FPS, less cores at a higher clock will yield better results. On the other hand, more cores will improve the speed at which new terrain textures, and autogen data load in.' (link here)

A nice little test. Personally, I am not really surprised that this 8700K does not provide more FPS than those due to the increased clock speed. However, it contradicts some user reports over the last months, but honestly, your results are more reasonable.

Nice comparison. I bought the 7700k right before the 8700k release and already knew that, for flight-simming, the difference would be small. Hopefully the future Cannon/Ice-Lake offerings will offer additional boost, specially for VR flying.

Well, the single core performance of the 8700K is not much higher, so it is no surprise that the FPS are not that much higher.

As OP said: it should help in texture loading and reducing blurries, which it seems to do (but hard to measure) :-)

I think the biggest improvement  increased multicore CPUs will gain is obviously when P3d has been properly optimized for it. You could have a 100 core CPU at the moment and it wouldn't make much difference, its still far to reliant on the first core.

 

When/if that happens the improvement gain will be just as big as going from v3 to v4.

This proves one thing for me (who uses a 6700 presently), not worth to upgrade yet. 

Thanks for taking the time to do this.

1 hour ago, B777ER said:

This proves one thing for me (who uses a 6700 presently), not worth to upgrade yet. 

I agree. Funny thing is that just after I have switched to i7-8700K and have launched Prepar3D for the first time, I had that 'feeling' that everything is smoother and faster. I am glad that I have made that benchmark to prove my 'feeling' wrong :). I guess I just wanted to see better results...

Well, there is small improvement, but not worth the money at this time.

It`s one of the reasons I went for the i7 7700k on a good deal for my flight sim build, I run 2 desktop PC`s both less than a year old, as for INTEL`s new ICE CPU we don't know what pin it will be on the 10nm chip may not be 1151. 

Interesting results. Thanks for posting.

Could you tell me what program is used to get the graphs and statistics for the frame rates?

Thanks,
Pete

 

Could you test with a multi monitor setup if possible as I think that the 2 extra cores will help in such a setup over a 4 core processor ?

Cheers can you load up the fsl 320.  PUT dynamic lighting on and fly to aerosoft EGLL at night with orbx England.  Interesting to see the results 

5 hours ago, twojastara said:

All six cores where running at 70-80%. GPU at same rate.

There is slight FPS gain in non-VR mode, but it could be explained with increased core speed. Suprisingly, there is no boost in VR mode.
However, what is worth notice is that standard deviation for i7-8700K is lower for around 2 fps (15%), and median is higher (12%) so it means we have more stable frame rate.

I have also noticed less bluries and faster textures and objects loading. I think that additional cores are used to process background tasks that load textures, objects and autogen. And that is confirmed with the quote from LM developer:

'The speed of the primary core will be the determining factor FPS assuming your settings have you CPU-bound. For raw FPS, less cores at a higher clock will yield better results. On the other hand, more cores will improve the speed at which new terrain textures, and autogen data load in.' (link here)

HT on or off? AM settings if any?

Nice reporting, excellent work. Confirms what we know about 6 cores.  As I move forward from 4 cores, I'll be allocating 4 cores to P3D and the rest to other software I'm running. I expect I will maintain about the same FPS while having a bit more processing power in reserve for other running software.

 

2 hours ago, GSalden said:

Could you test with a multi monitor setup if possible as I think that the 2 extra cores will help in such a setup over a 4 core processor ?

 

2 hours ago, tooting said:

Cheers can you load up the fsl 320.  PUT dynamic lighting on and fly to aerosoft EGLL at night with orbx England.  Interesting to see the results 

 

The problem is that my old CPU and motherboard is sitting in the box already waiting to be sold. But if I have more time, and I wouldn't find a buyer until then, I would do more tests. But I cannot promise that.

 

2 hours ago, Nemo said:

HT on or off? AM settings if any?

In both cases HT was off. No affinity mask.

I haven't changed anything in my sim configuration, or OS. I have just replaced new CPU and motherboard, upgraded BIOS and installed drivers.

 

3 hours ago, Pete Dowson said:

Interesting results. Thanks for posting.

Could you tell me what program is used to get the graphs and statistics for the frame rates?

Thanks,
Pete

 

 

Sure, the program is VfrFlight. I was developping for few years, but couldn't continue.

Interface is pretty clunky, but it does its job.

http://vfrflight.org

 

Cheers