Hyperthreading off works great!

[willy647 193]

25 minutes ago, dmiannay said:

+1 here as well.  "HT Off" lowers my average temps between 5-9C.

Which is only logical, since you're turning off half of the processor.

[Sartanius 399]

2 minutes ago, willy647 said:

Which is only logical, since you're turning off half of the processor.

And yet I have the same FPS regardless at 5.0GHz.  If you give me a choice of stable, high FPS with high temperatures vs. stable, high FPS with lower temperatures, I'll take the lower temps... every time.  There is no downside for me in P3D with HT off, just upside.

[simaddict 46]

Hello! Can someone tell me if I even have the option to turn of HT? I've looked in the BIOS and don't see anything related to HT on or off. But it's an 8 core Ryzen 7 1800X.

Thanks,

Mike 

[Sartanius 399]

9 minutes ago, simaddict said:

Hello! Can someone tell me if I even have the option to turn of HT? I've looked in the BIOS and don't see anything related to HT on or off. But it's an 8 core Ryzen 7 1800X.

AMD don't support Intel's Hyperhreading, but they do use something called “Simultaneous Multi-Threading”.  See if you have a BIOS setting for that.

Edited December 30, 2018 by dmiannay

[simaddict 46]

Thanks, Doug. That's interesting, I'll check the BIOS.

Thanks,

Mike

[Dirk98 354]

6 hours ago, Rockliffe said:

For as long as I can remember, rightly or wrongly, I have been flying with HT on with an AM setting of 85. I had no reason to turn it off, because everyone says running with HT on will utilise all cores and be more efficient and that has always been my understanding. 

Wrongly, had you asked me.

No matter what anyone would have told me about settings, tweakings, over clockings etc. my own eyes and ears would always be my ultimate guides.

Rockliffe may well be the only one who says, that running with HT on would utilise all cores and be more efficient, as reasoning for using HT.

Intel says HTT is a feature, that allows more work to be done by the processor during each clock cycle.

SteveW (the code legend)) ) says, that using proper and unique AM with P3D for your system is the key for the most efficient utilisation of your specific CPU potential and offers you scientific tools and methods for your private search in this non-linear quest.

I says, that it's your call to thoroughly search and find the most efficient settings for your specific system using all the powerful design features (talk about HT) of your hardware. This may become a very boring and time consuming task however you are unlikely to draw any sensible or credible conclusions regarding usage of HT with your P3D version by just flipping HT on/off several times and trying a couple of AMs.

For what it matters in my case initial engagement of HT had always been counterproductive for my system performance in my simulators, but has always eventually proved to become benefitial after a lot of shuffling and picking. Perhaps I took Intel's "HTT... allows more work to be done by the processor during each clock cycle" too seriously, but so far my practical experience has proved the opposite. In a hard way though.

 

 

Edited December 30, 2018 by Dirk98

[Mo45 32]

6 hours ago, Rockliffe said:

For as long as I can remember, rightly or wrongly, I have been flying with HT on with an AM setting of 85. I had no reason to turn it off, because everyone says running with HT on will utilise all cores and be more efficient and that has always been my understanding. Since installing v4.4 client I have never been very happy with things, particularly in the area of smoothness. So I decided to do a complete reinstall of P3D and Win 10, but anyone who has upwards of 150+ addons knows the kind of headaches that I could be faced with going down this path. Prior to doing so,  I thought  I'd take one more close look at things as I had an inkling that AF=85 maybe the culprit, so I ended up doing some further research and after using the AF calculator on the Gatwick page, I discovered that the AM setting should be 84 (?) Anyway, I tried 84 which made things worse, then I tried other possible settings... no setting gave me an acceptable flying experience. FPS were jumping all over the place and smoothness just wasn't there. I decided to turn HT off in the BIOS and run with no AM setting at all....!!! Wow, what a difference... a massive improvement in smoothness, more stable frames, quicker loading textures and a slight increase in FPS. Could this be for real I thought, and yes after further testing, it is for real.

Now, I have to admit as to being a little naive with things like process lasso, playing around with AM settings and moving different workloads to different threads etc etc. I'm just an average simmer who wants to fly. I guess this post is just because I'd like to hear some feedback regarding my experience. BTW, I had been running my i7 6700 with an OC of 4.5 for some time, but after a few BSODs decided to return it to clock speed. I am now wondering if after turning off HT whether I could return the overclock and see some more stability. I do notice that the CPU is running at about 75% now, as opposed to previously where it would be about 50%. Cheers fellas.

Why don't you have the HT on without overclocking.

[SunDevil56 183]

17 minutes ago, Dirk98 said:

SteveW (the code legend)) ) says, that using proper and unique AM with P3D for your system is the key for the most efficient utilisation of your specific CPU potential and offers you scientific tools and methods for your private search in this non-linear quest.

 

 

 

Well, I have to concur with Steve W, at least for my system and my experience with P3D.

It took me a long time to find an AM that gave me the best overall performance, and believe me, I tried many different "magic numbers" posted at various simming forums across the net.

[Rocky_53 1,566]

35 minutes ago, Jon123 said:

Why don't you have the HT on without overclocking.

Hi Mo, I have  been using it without any OC. It's only today I decided to try out an OC.

[DylanC 181]

I feel like something changed since P3D 4.3.  Ran into the same issue as you when 4.3 came out and got rid of HT, but still use process lasso.  I also run a 6700k @4.6G with a 1080ti. 

 

 

[kevinfirth 1,392]

Im reliably told by a code legend that the second thread now does more work in 4.4, so I have  my 8700K on an AM of 00 01 11 11 01 01 to make sure it isnt impeded by scenery loading.

[vgbaron 3,496]

9 hours ago, Rockliffe said:

I decided to turn HT off in the BIOS and run with no AM setting at all....!!! Wow, what a difference... a massive improvement in smoothness, more stable frames, quicker loading textures and a slight increase in FPS. Could this be for real I thought, and yes after further testing, it is for real.

Been there, done that years ago - been a happy camper ever since. Sometimes things that work fine in test suites just don't cut it in real application.

Vic

[honanhal 1,420]

I’m sure my experiments with HT would be dismissed as insufficient by some of the very particular gurus in this area, but I’d summarize my results as:

1) significantly fewer stutters with HT off

2) very slightly slower terrain/autogen loading with HT off (no free lunch after all)

3) much lower temps with HT off (up to 15 degrees C different at the same overclock) allowing for a higher overclock without HT

Bottom line, on my system with HT off there’s a slight (but undoubtedly real) disadvantage to texture/autogen loading but a massive advantage in smoothness and especially temps. What that temp difference means in real terms for me is the difference between running 4.6 GHz with temps spiking to 85 (eg probably safe but doesn’t feel great) and running at 4.7 GHz with temps never breaking 77. I’m never going back to HT on!

James

[hqmurphy 7]

A naive question - where does one turn off HT? NVIDIA control panel?

[Sartanius 399]

7 minutes ago, hqmurphy said:

A naive question - where does one turn off HT? NVIDIA control panel?

In your motherboard's BIOS.  It is typically entered during he early boot process by hitting either F2 or the DEL key.

Edited December 30, 2018 by dmiannay