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Sager P9872-S Hardware Quirks


AngieAndretti

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I've recently purchased Sager's new P9872-S laptop with Intel i7-6700K unlocked CPU and a single nVidia 1070 XMX GPU.  Let me say that overall I absolutely LOVE this new machine, but I've discovered some strange hardware/BIOS type quirks that I'd like to discuss here.  Note:  I don't see a version displayed in my BIOS, but HWINFO lists a BIOS date of 10/19/16.

  1. The CPU is unlocked and supports overclocking.  The stock BIOS also has a section for CPU overclocking.  My CPU is quite happy running a moderate 4.5GHz OC across all cores with a 70mV undervolt (offset mode.)  Yes it'll do the same clock at stock voltage but I've found that many Skylake CPU's do not need such high voltage as Intel has programmed them for - and my temps run much lower with the undervolt.  So I set the undervolt with Intel XTU (I've also tried doing the same with Sager's own utility) and it runs beautifully until I reboot the system.  At POST, BIOS then seems to reject the undervolt, forces a power-cycle, and sets CPU PL1 and PL2 power specs to very low "safe" levels.  It also changes the negative voltage offset to a positive 70mV, indicating that it's trying to "error correct" the negative value.  BIOS itself specifies a valid range of -500 to +500mV for the voltage offset here, and I can change it directly within the BIOS (and then it DOES actually stick through future reboots) but the BIOS does not allow me to enter a negative value here!  Instead of -500 to +500, the actual values it allows for entry are 0 to +1000!  And no, +500 does not actually equal zero, tried that and it really is +500.  Also of note, I can change any multipliers in XTU or Sager's utility without the BIOS objecting but *any change* to the voltage offset gets rejected at reboot - even +1mV.  Even applying +1mV and then immediately applying 0mV in either utility gets rejected on the next reboot so it's as if some checksums or something are not calculated the same way by XTU as they are by BIOS, causing a rejection of *any* voltage offset modification made by a utility rather than BIOS itself.
  2. Initially I set all my CPU core multipliers to 45x and all was good.  Soon I noticed that any time I put the computer to sleep or hibernate, it would limit core speed to a maximum 42x after recovering, despite still reporting 45x as the CPU maximum.  I tinkered with it for a while and eventually tried different values.  Now I have ONE CORE multi set to 46x and TWO, THREE, and FOUR CORE multi set to the original 45x.  That shouldn’t make a lick of difference versus 45x across the board but it does!  46, 45, 45, 45 sticks properly through sleep and hibernate; Weird right?  I’m fine with the current settings as an effective workaround but I feel it’s still worth noting here.
  3. The VSYNC seems "lazy."  I know this may be a driver or settings issue, rather than true hardware quirk, but it really bothers me - and the same behavior exists with nVidia drivers 368.xx to 373.06.  Take Dirt Rally for example; I want it to run with VSYNC ON at 1080p, 90Hz.  If I turn VSYNC OFF, my average framerate is about 200Hz, and never falls below about 110Hz, but with VSYNC ON it keeps dipping momentarily below 90Hz and skips frames!  In a fast-motion racing game this is very distracting!  I've observed this same behavior with the internal LCD and with my AOC 144Hz gaming monitor connected via DisplayPort.  With VSYNC OFF, even with framerate limiter set at or just above my refresh rate, the game looks terrible so this is not an acceptable workaround either.  Yes, the reported refresh rate is on target without VSYNC but there's terrible tearing and stutter.  I've never experienced this kind of VSYNC dysfunction before; any thoughts?
  4. I have the 1920x1080 120Hz LCD screen.  I wanted to set a couple custom refresh rates in nVidia Control Panel for racing games that really stress the system at 120Hz but I still want more than 60Hz.  If the LCD starts out set at 60Hz and I test a custom resolution of 1920x1080 at, say, 90Hz, the screen goes kaput until it reverts back to 60Hz.  However, if the screen starts out set at 120Hz I can then create any custom refresh rate in between 60 and 120Hz that I want.  I wouldn't bother trying to fix this one as there's a perfectly functional workaround - it's just weird to me that starting frequency matters.

Any thoughts on these quirks are welcome, and I’d be happy to try/test any good suggestion or curiosity you might have.  Especially getting a negative CPU voltage offset to stick permanently, as well as any thoughts on the VSYNC laziness would be greatly appreciated.  Thanks everyone!

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  • 3 weeks later...

Hi,

 

 I don't have a Sager but a P775DM3-G from pc-specialist and I faced the same problem with the voltage offset.

The BIOS only allows a positive offset, and indeed, an offset of 50 mV translates to +50 mV for the CPU.

I used the Clevo Control Center Hotkeys utility to set an offset of -150 mV, which is effective as negative offset.

Going into the BIOS, it actually shows as 150 mV (without -), but as long as I do not change it in the BIOS, even when I save BIOS settings, the applied offset remains -150 mV.

 

Cheers

Qon

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  • 2 weeks later...

Some Successes!

 

Thanks a lot for making me look into this deeper, Qon.  I had originally tried something similar without success: I set a negative offset within the OS, at first using Intel XTU, as I find it preferable to the Sager control center software and as I said it would work UNTIL I'd reboot the system.  Upon reboot, BIOS would immediately powercycle the system and change that negative to a positive value along with changing the CPU PL1 and PL2 limits to very low values, about 30w limit.  When the system then got into Windows, I could see in XTU that we were now running a positive overvolt and this was confirmed with HwInfo64 - the CPU was truly getting more voltage rather than less.  I did try that same process once with Sager's control center before my first post and I initially got the same result, but your post made me check deeper...

 

After reading your suggestion that it actually might be possible to get this working, I tried setting a negative offset again using the Sager software but I noticed something strange: When I clicked "Save" after selecting the undervolt, the Save button remained highlighted as it seems to do when it's trying to indicate that there are unsaved settings being displayed.  So I clicked it a second time and only then did it become gray, likely indicating the settings had in fact saved.  Upon reboot the machine still powercycled that one first time and BIOS did still display a positive offset value but the PL1 and PL2 values remained untouched this time and now when booting to Windows, we actually hold the correct undervolt despite BIOS displaying the positive value.

 

So the takeaway for others is this: If you're having this issue with CPU undervolt not sticking or getting inverted to a positive value when setting it in Sager's Control Center, try clicking Save a second time after selecting your preferred settings, or until the Save button returns to being gray.

 

Now regarding the "Lazy VSYNC" issue I mentioned in which framerate often dropped notably below the chosen refresh rate without the CPU or GPU indicating that they were being taxed significantly at that moment.  I don't know for sure if this is a Pascal-specific issue but I can say the same games that exhibited this issue played flawlessly with the same nVidia driver versions installed on my Maxwell-based laptop.  I did a lot of tinkering with nVidia Profile Inspector (v.2.1.3.4) and I found the following settings to be a near-perfect fix, at least in the games I was having issues with:

  • Variable Refresh Rate:  0x00000000 VSYNCVRRCONTROL_DISABLE
  • Framerate Limiter 2 Control:  0x00000002 PS_FRAMERATE_LIMITER_2_CONTROL_AVOID_NOOP (or) 0x00000011 PS_FRAMERATE_LIMITER_2_CONTROL_DEFAULT_FOR_GM10X (depending on game)
  • Frame Rate Monitor:  0x00000010 PS_FRAMERATE_LIMITER_GPS_CTRL_TARGET_RENDER_TIME_SHIFT
  • Frame Rate Monitor Control:  0x0080F364 PS_FRAMERATE_MONITOR_CTRL_VSYNC_OPTIMAL_SETTING

Note these settings are to be used in conjunction with VSYNC ON, as the issues I was having were specific to VSYNC being ON.  These settings also work great with Power Management Mode set to "Optimal Performance" (Profile Inspector) = "Optimal Power" (nVidia Control Panel) which allows the GPU to only clock up as high as it needs to in real-time.  They in fact work far better than simply setting Power Management Mode to "Prefer Optimal Performance" which tends to keep the GPU clock rate high at all times, which I find very undesirable on a laptop.

 

I also found the answer to my #4 quirk, in which only the 120hz internal display setting could be used as a template for creating custom refresh rates in between 60 and 120hz.  It was because the native 60hz configuration, for some reason, had about 1,000 extra "total pixels" programmed onto the back end of the vertical refresh in the display timings, leading to the 60hz pixel clock being the same as the 120hz pixel clock.  Don't ask me why they did that, but if you try to increase the refresh rate using the 60hz template, you end up with a pixel clock that's too high and out-of-range... unless you reduce the "total pixels" vertical setting in the display timings to a lesser amount.

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