Interaction Between RTSS and Core Affinity

Discussion in 'Rivatuner Statistics Server (RTSS) Forum' started by DaRkL3AD3R, Mar 6, 2023.

  1. DaRkL3AD3R

    DaRkL3AD3R Active Member

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    Tomorrow I'll be getting my 7950x3D and planned on utilizing it in the following way:

    - All background and system tasks stay affinity masked to the high frequency cores
    - All games are manually affinity masked to just the 3D cache cores, unless the game is not cache sensitive

    My concern comes with how RTSS interacts with a game and what affinity masking will do when jumping across CCDs. The logic is that if an application that is latency sensitive has to jump from one CCD to the other to complete a task, this will incur a significant performance penalty and so to avoid this, the application will be locked to a single CCD.

    The problem is, what happens when RTSS hooks into a game that is affinity masked to a different CCD? Do the threads that RTSS injects into the game become affinity masked to the cache CCD now? Does this incur the cross-CCD performance penalty? Should RTSS be left on the same CCD as the game then? And what about MSI Afterburner being the data supplier for RTSS? Obviously MSI Afterburner by itself not logging data to the OSD can be ran on the frequency cores separate from the game and everything will be fine, but what happens if RTSS is affinity masked to a different CCD now?

    These asymmetrical CPUs are a real headache and I'm a bit concerned what I'm going to find tomorrow when I get this system all setup. I expect it's going to be awhile before I get any concrete answers and learn some hard lessons that I won't be happy with.
     
  2. Unwinder

    Unwinder Ancient Guru Staff Member

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    Hook modules do not contain any affinity mask switching logic. Main process temporarily locks itself to each core when reading sensors specific to it. The same apply to any CPU monitoring software.
     
  3. Andy_K

    Andy_K Master Guru

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    afaik, from what I've read in all reviews this is how it works in Win11 out of the box, with BIOS, chipset driver and Windows all up to date. AMD and Microsoft worked together to get it working in just this way.
     
  4. Astyanax

    Astyanax Ancient Guru

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    not exactly, the way they did it is using a forced core parking of the upper core masks, which is actually a problem in itself because you then can't use those cores for low op tasks such as voice chatting lmao.
     
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  5. bensam123

    bensam123 Member

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    Yup and running background applications will cause cores to become unparked, which will then load them, and mess up the 'AMD scheduler' if you want to call the bandaid that. I pushed really hard to try and get reviewers to test a slightly bloated/loaded Windows install to start and shine light on this and no one responded, and in one place one person getting really agitated that I would even ask for such a thing, because it can't be a problem... as it's never been tested.

    Core parking in general being pretty terrible and not something you want to ever actually be on. It's forced on as a bandaid to try and move threads around because the MS thread scheduler is so terrible. In a ideal world core parking would only ever be used for power efficiency, not trying to coax the thread scheduler into doing what AMD wants.

    I just a bought a brand new 13900k after looking at the possible problems with X3D if you want to buy more then a 7800X3D and core parking is forced on by either Intel or MS. I have core parking off in the OS, but there is either a driver or some sort of override that is on that still causes it to turn on. It's not as strong as having the OS option on, but it's still there and cores still park in Resource Monitor. Turning off C-States causes the processor to simply ignore core parking and load up the cores regardless, but it still says they're parked. Surprised no one is talking about this, I expect it's the same with the 12K series.
     
  6. Andy_K

    Andy_K Master Guru

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    Could Process Lasso help to avoid this issues?
     
  7. bensam123

    bensam123 Member

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    For me, no. If you assign it to cores and windows parks the cores anyway, it wont use them. You can force it onto a small amount of cores to make them active, but it negates the purpose of having a lot of cores to have ample headroom. For instance I assign Overwatch to my 8p cores and it will still try to park 3/8 of them.
     
  8. DaRkL3AD3R

    DaRkL3AD3R Active Member

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    Well I can confirm that things are working GREAT for me right now with the 7950x3D. I did things exactly like I thought I would: disable all their automated BS "scheduler" crap, don't even install the V-Cache driver, set the BIOS to prefer frequency cores, then use Process Lasso to coral different games and programs to one CCD or the other. It's working flawlessly for me so far. I'm not seeing any performance loss doing this vs letting their crappy automatic core parking behavior take over. In fact, I feel like I'm getting even better performance. For instance in RE2 Remake, my CPU bottleneck spot, with automatic settings I would get around 340 fps, but with my manual override stuff I'm getting 380 fps. I'm pretty happy with that aspect of this system.

    The thing I'm not happy about is the newfound sound crackling coming from my Creative X-Fi Titanium PCIE card, and the general instability and struggle with EXPO settings. I truly don't believe my system is 100% stable at stock settings and that has me super nervous. I'm afraid to even try EXPO2 because the voltage SHOOTS to the stars on the IMC. It goes from 1.1v to 1.44v. Idle power consumption skyrockets nearly double. And all this for something I really don't notice the performance difference from. Lastly I'm also experiencing random windows stuttering when dragging them around the desktop. Something like Task Manager will freeze for a frame or two while moving the window around. It's just bizarre to me how this chip can be so freaking fast in the right full load gaming situation, and fall apart at idle or general easy tasks.
     
  9. bensam123

    bensam123 Member

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    So to update on this, it seems this is a W10 thing... It actually looks like W10 intentionally seems to be hobbling the processor. My 5900x would use 8 cores on w10. My 13900k would be pushed onto 5p cores, even though I set 8p cores in process lasso, it forcibly parks 3p of the 8p cores - even with core parking disabled. Disabling C-States causes the CPU to ignore the core parking status, however w10 will still try to force all the threads onto 5p cores...

    I changed to w11 and core parking is now completely gone from resource monitor, while having it disabled on a OS level... this is almost feeling like MS is intentionally hobbling w10 I assume to force people to upgrade. The performance difference is small, but there. Insane for a 24 core processor.

    I would check to see if it has MSI mode on, if so disable it. My 5900x eventually had issues with it locking up at idle and I had to RMA a year and a half later.
     
  10. Astyanax

    Astyanax Ancient Guru

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    windows 10 can't use E cores properly, there is no intentional of anything, it doesn't know how to use two tier architectures and never will.

    the XFI cannot and will never support MSI using the Creative drivers, if a user has turned it on then they will not have any sound on the next boot.
     

  11. bensam123

    bensam123 Member

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    Welp, it is intentionally parking cores that goes beyond normal core parking, as it can't be disabled and disables 3 out of 8p cores... It is intentional as it overrides the OS level disable of core parking. It's not really about supporting it, rather it's about intentionally hobbling it.

    Usually it results in crackling and popping, not just no sound. I'd imagine just not working is also possible as well depending on which one you have.
     
  12. DaRkL3AD3R

    DaRkL3AD3R Active Member

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    Yeah can confirm MSI mode on the Creative driver = no sound next boot. I just hope whatever's going on with my system gets kinked out over time with BIOS patches and what not. Let me guess CPU warranty on these things is only 1 year right? Would be screwed if it flaked out in 1.5 years.
     

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