Core i9 7900X for P3D v4

[adyfoot 19]

48 minutes ago, supersym said:

 

did'nt you try 1.2 volt or 1.25 @ 4.4,4.5 ... ?

60 ° with the CPU, I think it's possible...

With my motherboard, all advice seems to be to leave vCore in Auto.  I've only tried 4.3 GHz at the moment.  I might try for 4.4GHz and, if it passes the stability tests, leave it there for now.

[adyfoot 19]

14 minutes ago, orcunizma said:

I really hope I can clock a 7820x to around 5GHz with delidding and water loop. And due to 2 less cores there also should be less heat right? Otherwise I will have to wait what the Threadripper or Coffee Lake is capable of as this would be no option for me. :/

By the way is your HT on or off? Can you post your temps under stress test with HT off?

Thanks

Delidding has been proven to knock a good chunk of heat off these new chips - but you void your warranty and I certainly wasn't ready to do that on such an expensive chip.

Everything is with HT on at the moment.  Once I get P3D installed, I'll do some experimentation and see if it likes HT on or off.  If I turn it off, I'll almost certainly be able to get more out of the OC.

[orcunizma 2]

3 minutes ago, adyfoot said:

Delidding has been proven to knock a good chunk of heat off these new chips - but you void your warranty and I certainly wasn't ready to do that on such an expensive chip.

Everything is with HT on at the moment.  Once I get P3D installed, I'll do some experimentation and see if it likes HT on or off.  If I turn it off, I'll almost certainly be able to get more out of the OC.

Hey, with HT off and custom watercooling Im sure you can get to 5GHz area! :-)
Also who needs HT with 10 cores? Not for the next years for sure :))

[SteveW 1,792]

When two equal threads run on one core they are time-sliced so they appear to run at the same time. These two threads finish behind the same two threads running on an HT enabled core (one per LP). Switching HT off is wasting a lot of valuable throughput, which if unmanaged will get your CPU hot since:

 

 - more work done in the same time = more heat generated -

 

Remember that P3D aint a 20 minute Doom session till we puke. P3D systems are run day and night, hour upon hour. They prefer a slightly more relaxed setting on the overclock, one that accommodates HyperThreading.

HT when used correctly easily soaks up the cycles we lose with the moderate OC. These sim PCs are best set with HT enabled no matter how many cores, however they are set knowing that they must run P3D (and other apps) with care and an appropriate Affinity Mask or the thing don't run properly. Turning off HT saves some head scratching and worry, but then so does two feet staying on the ground.

Since the first two processes do the main job followed by as many cores as you like, after six there's nothing for them to do they become unused baggage, running up to the point of strain available from the hardware. After that it matters not how many cores we throw at it, makes matters worse.

So even with HT off we need to understand what certain apps and processes do when confronted with a large LP count.

[orcunizma 2]

12 minutes ago, SteveW said:

When two equal threads run on one core they are time-sliced so they appear to run at the same time. These two threads finish behind the same two threads running on an HT enabled core (one per LP). Switching HT off is wasting a lot of valuable throughput, which if unmanaged will get your CPU hot since:

 

 - more work done in the same time = more heat generated -

 

Remember that P3D aint a 20 minute Doom session till we puke. P3D systems are run day and night, hour upon hour. They prefer a slightly more relaxed setting on the overclock, one that accommodates HyperThreading.

HT when used correctly easily soaks up the cycles we lose with the moderate OC. These sim PCs are best set with HT enabled no matter how many cores, however they are set knowing that they must run P3D (and other apps) with care and an appropriate Affinity Mask or the thing don't run properly. Turning off HT saves some head scratching and worry, but then so does two feet staying on the ground.

Since the first two processes do the main job followed by as many cores as you like, after six there's nothing for them to do they become unused baggage, running up to the point of strain available from the hardware. After that it matters not how many cores we throw at it, makes matters worse.

So even with HT off we need to understand what certain apps and processes do when confronted with a large LP count.

So why is everyone getting higher frames with HT off and higher clock than with HT on and lower clock? If you have 10 cores, why would you need HT? So 10x 5 GHz for me makes more sense then 20 cores at lower speed or no?

[SteveW 1,792]

3 minutes ago, orcunizma said:

So why is everyone getting higher frames with HT off and higher clock then with HT on and lower clock? If you have 10 cores, why would you need HT? So 10x 5 GHz for me makes more sense then 20 cores at lower speed or no?

I said I am referring to a more relaxed PC. You need to do some homework on what HT is all about to see the funny side of your comments.

 

[orcunizma 2]

2 minutes ago, SteveW said:

I said I am referring to a more relaxed PC. You need to do some homework on what HT is all about to see the funny side of your comments.

 

I know what HT is about but I said for Prepar3D its better to leave it off so you can get a higher base clock since this Sim is not even using other cores properly it's just poorly coded.

[SteveW 1,792]

Yes if you read my comment it is obvious I am aware that core frequency means higher fps are attainable and that turning off HT makes that easier to do since it does less work = less heat at the same frequency - that means there is a trade off in valuable background processing which is now the holy grail of the smooth sim.

[orcunizma 2]

Just now, SteveW said:

Yes if you read my comment it is obvious I am aware that core frequency means higher fps are attainable and that turning off HT makes that easier to do since it does less work = less heat at the same frequency - that means there is a trade off in valuable background processing which is now the holy grail of the smooth sim.

OK read it the other way around thats why I had a few questionmarks ;-)

[SteveW 1,792]

As I am saying turn off HT save the head scratching but you may want to restrict the sim to 6 cores. With the moderate overclock we need to be sure HT is working properly, have a look at this shows how the sim typically works when it sees different LP counts:

What is interesting is to watch your graphs when the sim is busy with loading duty.

 

[orcunizma 2]

22 minutes ago, SteveW said:

As I am saying turn off HT save the head scratching but you may want to restrict the sim to 6 cores. With the moderate overclock we need to be sure HT is working properly, have a look at this shows how the sim typically works when it sees different LP counts:

What is interesting is to watch your graphs when the sim is busy with loading duty.

 

This is head scratching  always been. So basically our SIM is only able to use 4 cores? So 245 setting would be the best in this graph, correct? Let's say we have 10 cores, I wouldn't be able to make the full benefits of it and only use 4 cores? Like you said restrict the Sim to 6 cores, how would you do that and does it make it that much better?

EDIT: This graph is a quad core with HT on right?
EDIT2: I need some sleep

[SteveW 1,792]

Well, the CPU can only do loading tasks up to the point which the hardware can give up no more. So there will be a limit to the number of processes spawned to do that. And then the faster the CPU is, the faster it can do those loading tasks, needing less loading processes.

In the graphs 245 shows pairs of these processes using up more bandwidth than the same pair can do on one core (non HT) and loads the scenario in the same time as three cores.

[orcunizma 2]

28 minutes ago, SteveW said:

Well, the CPU can only do loading tasks up to the point which the hardware can give up no more. So there will be a limit to the number of processes spawned to do that. And then the faster the CPU is, the faster it can do those loading tasks, needing less loading processes.

In the graphs 245 shows pairs of these processes using up more bandwidth than the same pair can do on one core (non HT) and loads the scenario in the same time as three cores.

Im not up to date anymore, last time I flew it was FSX in 2015 because of its VAS restrictions. 1 last question, is Prepar3D automatically setting the Affinity Mask or do you still have to configurate it yourself. What would be the best setting for a 8 core and HT on? Thanks Steve

[SteveW 1,792]

What I've shown in the graphs is that P3D v4 gives the leanest rendering section with six LPs or more.

I've used 245 since that allows the four core to split the sim over six parts and lean up the first two jobs. It's pretty clear now that no AM means those processes regrouping back onto less cores. No AM with HT enabled, or allowing the first two jobs to utilise the same core, one per LP, won't be so bad if we really need more loading speed, at least those first two parts have an LP to themselves. 85 might be better though, meaning four core HT off still works well.

So with six or more cores what to do. Try the 245=11,11,01,01 pattern as 980=00,11,11,01,01,00 on the six core leaving a core free each end, or one LP per core 1365=01,01,01,01,01,01, move that up a core with 8 cores 5460=00,01,01,01,01,01,01,00 - if you look there's your no HT right there restricting the sim processes to alternate LPs = one job per core. What you still need to do is keep addon exe apps away from those cores with the sim. And if you're flat-lining the GPU with AA or objects, those AM changes might appear to make nonsense in terms of performance.

With HT off six core no AM=111111, addons on 110000

HT off 8 core AM=126=01111110, addons on 10000001

 

[Noel 4,484]

1 hour ago, SteveW said:

With HT off six core no AM=111111, addons on 110000

HT off 8 core AM=126=01111110, addons on 10000001

Steve, sir, please tell me what, IYHO, the best CPU would be for P3D V4, trying to hedge for better utilization of multicore CPUs down the road.   As I've said before single core performance has change minimally over the past 5y and it seems the base sim plus addon devs should be looking to access multi cores better to enhance total performance.   I've had the 3930K you helped me set up for the right AM, but I think this system has died--I'm waiting to hear news from ASUS on whether or not my motherboard can be fixed in which case I may be able to continue using the 3930K.    If not I have to start choosing parts ASAP--I really miss it!

I'm leaning towards 7820X with its 8 cores and so far has the best single-core performance of any of the  i7/i9 X processors currently.  But I'm open to other opinions!