13900KS + RTX4090 Build Notes

[Bob Scott 7,782]

On the 13900K with HT on, you have 32 virtual processors, not 24 (2 on each of the eight p-cores, and one on each of the 16 e-cores).  With HT off, you have 24 VPs, all of which are physical processors.

If you want to cool things down to get some thermal headroom, in addition to turning off HT, you can disable a bank of four e-cores, leaving you with 8p + 12e, or 20 VPs, which is more than enough.  That's how I'm running my 13900KS--I have the CPU overclocked to 6.0 GHz on one core where P3D's main thread runs and 5.8 GHz on the remaining seven P-cores, but I also run very aggressive water cooling in an 18 deg C room -- two 360mm deep radiators in series plumbed with 0.5" ID tubing and a high flow Laing D5 pump.

To disable e-cores (you need to do it in groups of four) you enable "Per E-Core Control" and you'll then see a list of the 16 e-cores...you can then disable e-cores individually.  To confirm you have an entire bank shut down, you can go into Extreme Tweaker -> Specific Efficient Core, and you should see E-Core ratio limit and voltage for only three active banks, which is indication that the fourth and unlisted bank is shut down.  If you don't disable all the e-cores in the bank (aka "Group"), you'll still see the ratio limit and voltage setting options listed, which indicates the bank is still powered-up and producing heat.  In my case, I have the last four e-cores (12-15) disabled, and on the Specific Efficient Core page I see ratio limit and voltage setting options only for Group0 (e-cores 0-3), Group1 (e-cores 4-7) and Group2 (e-cores 8-11), and nothing for the now-depowered Group3.  With HT off and a bank of e-cores shut down, if you use an AM it should be 20 bits, reflecting the 20 operating VPs.

[Ray Proudfoot 9,074]

@Bob Scott, many thanks for that. I’ll give it a go tomorrow morning and report back.

Like you I limit fps to 30 via a 30Hz monitor and VSync.

My room is also around 18-20C with no central heating required. The two computers keep it warm!

[Ray Proudfoot 9,074]

Hi Bob,

I disabled HT and in the Extreme Tweaker section disabled the last four e-cores (12-15). Despite doing that they still showed as Auto in the Specific Efficient Core page.

I was sure I had disabled the last four so saved and exited the BIOS. In Windows - Task Manager - Performance it lists just 20 Cores / LPs. That would suggest I disabled the last 4 successfully.

In Prepar3D.cfg I changed the AM to 1048405 for both AM and P3DCoreAffinityMask. That is derived as follows:-

11111111111101010101

I'm about to start a flight so I'll report back later.

LATER: Anyone doing this be aware the change in LPs is detected by ActiveSky and you are prompted to enter a code sent via email. I did that and AS launched okay.

[Ray Proudfoot 9,074]

I’m back after testing with the same Concorde flight as yesterday. No real change to CPU temps. Still peaking in the high 90s°C and with fewer VPs too.

FS Labs are working on a big fix for it so I’m inclined to wait until it’s released and then assess things.

Given the computer didn’t shutdown or throttle because of heat issues I’m guessing it isn’t something potentially terminal.

[Ray Proudfoot 9,074]

I’ve re-enabled the four e-cores as the temperature didn’t drop without them. I’ve left HT disabled.

I’m struggling to understand why so many of the cores are being used when I’m currently flying over open ocean in Concorde up the east coast of the US from Miami to Raleigh-Durham. Surely the aircraft’s many gauges aren’t that demanding.

[Bob Scott 7,782]

On 11/29/2023 at 3:38 AM, Ray Proudfoot said:

Hi Bob,

I disabled HT and in the Extreme Tweaker section disabled the last four e-cores (12-15). Despite doing that they still showed as Auto in the Specific Efficient Core page.

I was sure I had disabled the last four so saved and exited the BIOS. In Windows - Task Manager - Performance it lists just 20 Cores / LPs. That would suggest I disabled the last 4 successfully.

In Prepar3D.cfg I changed the AM to 1048405 for both AM and P3DCoreAffinityMask. That is derived as follows:-

11111111111101010101

I'm about to start a flight so I'll report back later.

LATER: Anyone doing this be aware the change in LPs is detected by ActiveSky and you are prompted to enter a code sent via email. I did that and AS launched okay.

Yikes--That's a really bad AM if you have HT off--that makes four of your eight p-cores unavailable to P3D, which is definitely not something you want to do. 

The pairs of 01 are what you might use with HT on, so that it blocks P3D from using one of the two VPs on each HT-enabled CPU core.  With HT off all the VPs are physical cores, so that 01010101 sequence blocks every other physical core, and in this case the rightmost eight binary digits in the mask represent the p-cores, which are much faster--something on the order of 30% faster.

[Ray Proudfoot 9,074]

13 hours ago, Bob Scott said:

Yikes--That's a really bad AM if you have HT off

I realised my mistake later yesterday. I'm so used to HT being on I'd forgotten the rules.

My new AM setting is 16777215 which turns on all 24 LPs. The other settings are 0, 2 and 4.

It was @SteveW who suggested leaving the decision to P3D if you have HT off. That's the result which I hope is optimum for the CPU.

[Luke 783]

Have you guys looked at setting PL1 and PL2 values? Generally speaking with both Intel and AMD chips you'll trade a single-digit level of performance for a 25-30% amount of heat.

Cheers

 

[jlohrenz 133]

On 11/29/2023 at 7:54 AM, Ray Proudfoot said:

I’m back after testing with the same Concorde flight as yesterday. No real change to CPU temps. Still peaking in the high 90s°C and with fewer VPs too.

FS Labs are working on a big fix for it so I’m inclined to wait until it’s released and then assess things.

Given the computer didn’t shutdown or throttle because of heat issues I’m guessing it isn’t something potentially terminal.

Ray,

  I'm still struggling with this comment of 90C while in sim.  I have the 14900k and the only time I've hit 90C was when I was doing some benchmarking.  When flying in p3d i'm in the mid 50's to lower 70's at times.  I've got a corsair AIO.  

[Ray Proudfoot 9,074]

16 minutes ago, Luke said:

Have you guys looked at setting PL1 and PL2 values? Generally speaking with both Intel and AMD chips you'll trade a single-digit level of performance for a 25-30% amount of heat.

Cheers

 

What is PL1 and PL2? Never heard of it.

[Ray Proudfoot 9,074]

5 minutes ago, jlohrenz said:

Ray,

  I'm still struggling with this comment of 90C while in sim.  I have the 14900k and the only time I've hit 90C was when I was doing some benchmarking.  When flying in p3d i'm in the mid 50's to lower 70's at times.  I've got a corsair AIO.  

Have a look at this screenshot of RTSS / MSI Afterburner monitoring. It perplexes me why the temps should be so high when...

1) I have VSync enabled on a 30Hz monitor so fps are set at 30.

2) I'm currently flying over the North Sea from Manchester to Copenhagen. Why so much work by the VPs?

Maybe it's the aircraft. FS Labs Concorde currently at Mach 2, FL520. But the only scenery is water and there are currently 3 Ai in my 80nm bubble. Maybe it's Concorde's FE panel.

[Bob Scott 7,782]

@Ray Proudfoot  How are you cooling the CPU?  And how are the CPU voltages set?  My first suspicions would be either the use of an auto-overclock which, as most auto-overclocking is prone to do, is jacking your voltages up way too high.  Alternatively, it could be a problem with CPU cooling--something like a wimpy fan curve on an AIO or a bad application of TIM.  But yeah, 100C at those loads looks aberrant to me.

I also agree that the loading across the cores looks way too high for P3D.  I'd use something like Process Lasso to rule out something else that might be running other than P3D that accounts for that load.

I haven't played with PLs (power limits), as lowering them drives the CPU to clock down to stock after prolonged periods of high load, and prolonged periods of high load are normal flight sim behavior.  I run HWInfo64 remotely via the LAN and watch power (and voltages) on a separate PC during my overclocking stress tests and when testing a flight sim config on a new or modified build, just to keep things sane.  If it gets too high, I adjust it by reducing the clock mults and/or CPU core voltage.

 

[Ray Proudfoot 9,074]

Bob, the computer was built by Chillblast here in England who have an excellent reputation. The CPU cooler is a Fractal Design Celsius+ S24 Prisma 240mm All-in-One Liquid CPU Cooler. I ordered a different one but it wasn't available and Chillblast recommended this. I also have Thermal Grizzly paste to aid cooling.

In the Main section of the BIOS. On the right - Hardware Monitor I have:-

Frequency 5500MHz Temp 49C
BCLK 100.00 MHz Core Voltage 1.439V
Ratio 55x  DRAM Frequency 6000MHz
MC Volt 1.314V  Capacity 32768Mb.

Looking at the BIOS in Extreme Tweaker.

Ai Overclock Tuner is D.O.C.P.I

DOCP is DDR5-6000 30-36-36-76-1.40V

CPU Core Auto Voltage Cap is Auto
CPU Input Auto Voltage Cap is Auto

There's more on the right so I'm attaching a photo. Anything you can suggest will be appreciated. If it needs better CPU cooling I'll talk to Chillblast.

I've also gone into QFan Control and increased most from Standard to Turbo. I'll see how that affects things.

[Luke 783]

1 hour ago, Ray Proudfoot said:

What is PL1 and PL2? Never heard of it.

You'll want to start here - it's for the 10x00 series, but it's essentially the same: https://www.hardwaretimes.com/intel-10th-gen-cpu-power-consumption-explained-pl1-pl2-and-tau/

The ASUS BIOS doesn't explicitly label it as such, and my Z390 board is awaiting transplanting, but I would look for "Power Limit 1 / 2" or " Long / Short Power Limit". For the K series you absolutely want to set this, because they will happily consume as much power as they can draw on default settings. I found that over time my i7-9700K got  warmer and warmer since I was generating more heat than the heat sink could dissipate, but only barely. Adjusting PL2 down to 160W solved the issue with no discernable performance impact.

If you have a K-series Intel, you should be familiar with how to adjust them and the impact.

Cheers

[mattius123 4]

@Bob Scott Hi Bob, I'm using the same CPU as you and I used Steve's AM recommendation for the 13900K in the P3d.cfg. I don't have the same sort of setup GPU wise (3080gtx) and I don't consider myself an expert in the Bios, I've left it on automatic and HT is left enabled. Can you advise what AM setting you are using in the cfg please as I'm registering 90 to 100 C temps when Im in flight.

Many thanks!

Specs: MSI MPG Z790 CARBON WIFI, 13900KS (Stock clock), DDR5 32GB 6000MHZ KINGSTON FURY RENEGADE, CORSAIR ICUE H150I, CORSAIR PSU 1000W RMX SHIFT SERIES RM1000X