Mobile Pascal TDP Tweaker Update and Feedback Thread

Discussion in 'Sager and Clevo' started by Coolane, Jun 20, 2017.

  1. Falkentyne

    Falkentyne Notebook Prophet

    Reputations:
    6,311
    Messages:
    5,107
    Likes Received:
    6,888
    Trophy Points:
    681
    Ok where are all the techheads here?
    @Meaker@Sager @Prema (the God), @bloodhawk

    The Texas Instruments IC's are rated for 40A operation (under recommended operating conditions) and 90% efficiency at 25A.

    http://www.ti.com/lit/ds/symlink/csd87350q5d.pdf

    So that means if a MSI GTX 1070 (MSI makes the Clevo cards also) has FIVE PHASES, that would seem to imply the card is 100% stable and guaranteed to run at the full MXM specification of 200W (195W) without having Chernobyl 2.0 in your living room. But can one of you please explain this VRM layout?

    there are 5 phases, if each choke counts as a phase.
    But why are there two mosfets connected to one phase? What exactly is going on there?
    Is each mosfet a pair (e.g. Sync Fet + Control fet?), or is there some sort of doubling going on?

    How much is each pair exactly? Are we looking at 200W of mosfets or 400W?
    (@Khenglish mentioned once 400W, but this has to be a complete mistake).

    It also "seems" like they can burst operate up to 60 amps (in which case 60 * 5 =300 watts), but not sustained. Only 40 amps (*5= 200W) is guaranteed sustained.

    Anyone want to explain?

    Look at the CPU MOSFETs here for this BGA: 5 phases=5 chokes:
    You see clearly 1 mosfet linked to a phase.

    ivanpicture1.jpg

    Now look at the 1070 MXM card:
    Using TI mosfet: csd87350Q5D

    MSI_1070_SINGLE_FRONT.jpg.a4175788b986d574fd81924620746858.jpg


    MSI_1070_SINGLE_BACK.thumb.jpg.175938d34b248883e934545c038d1f72.jpg
    someone want to help a brother out here? :( @Papusan i want to swim please.
    *Edit* please don't get me started on how X watts become Y amps...and pascal supply GPU voltage (1.0625v) i'm confused.
     
    Last edited: Jun 3, 2018
    Vistar Shook likes this.
  2. Khenglish

    Khenglish Notebook Deity

    Reputations:
    502
    Messages:
    715
    Likes Received:
    503
    Trophy Points:
    106
    It's just 2 power FETs per phase to double the max current.

    1 power FET = 40A
    one phase = 2 power FET = 2 * 40A = 80A
    5 phases = 5 * 80A = 400A
     
  3. Meaker@Sager

    Meaker@Sager Company Representative

    Reputations:
    7,623
    Messages:
    47,922
    Likes Received:
    12,940
    Trophy Points:
    931
    You can also have 2 inductors per phase to trick people into thinking there are more phases than there really are.

    Doubling the VRMs per phase increases capacity, you are still mostly as efficient (small extra losses) but you can now handle double the current at the same efficiency (20% of 100W is still bigger than 20% of 50W of course for instance).

    It does not improve ripple or other electrical characteristics.
     
    Falkentyne likes this.
  4. Falkentyne

    Falkentyne Notebook Prophet

    Reputations:
    6,311
    Messages:
    5,107
    Likes Received:
    6,888
    Trophy Points:
    681
    Why would MSI even bother to do this?
    Why would they design a card that can handle 230W+ (or up to 330W) easily without frying, and limit it to 150W (original design specification) TDP ,and 115W-125W TDP (MSi and Clevo boards--MSI makes the Clevo models) on release? What's the point of overspeccing a card like this? Doesn't it just add cost? Especially since no one would ever be able to run a card this high? (without both bios mods, shunt mods and hardware voltage mods?)

    Or did MSI just copy part of the design for its desktop cards and chop them down with a chainsaw?
     
  5. senso

    senso Notebook Evangelist

    Reputations:
    189
    Messages:
    565
    Likes Received:
    93
    Trophy Points:
    76
    Stability, reliability, ripple, dI/dT, keep MOSFET's under SOA, EMI/RFI, performance/behaviour when its running with low loads -> low current, usually done with discontinuous mode, two FET's in parallel give you a lower RDSon, so it also plays into what inductor you can use, to maximize Q.

    Tons of reasons.

    Just like everything, the first page of a datasheet is marketing wank..

    At 40A that MOSFET is dissipating nearly 10Watts when it switching at 500Khz, thats a LOT to dissipate with that small footprint.

    And then there is the SOA, page 5, look at the SOA curves..

    RDSon goes up with temperature, the more current you drawn, the higher the junction gets, and the higher it gets, the more it will heat, its a positive feedback loop, so using 400 marketing Amps for a real world use of 100-150A seems a decent design.

    If they went by the first page "specs" you would have a card that would blow up if you even typed furmark on the search bar..
     
    bennyg, raz8020 and Falkentyne like this.
  6. Meaker@Sager

    Meaker@Sager Company Representative

    Reputations:
    7,623
    Messages:
    47,922
    Likes Received:
    12,940
    Trophy Points:
    931
    Because the efficiency is a curve generally. By "over" speccing the VRM full load is much closer to optimal efficiency and there will also be typically less component failures and less heat dumped into the heatsink and PCB (spreading the VRMs out by having more also makes cooling easier)

    You also have to consider trace sizes and the abilities of the VRM heatsink/supporting components and consider it as a full system.
     
    bennyg, raz8020 and Falkentyne like this.
  7. Songoku999

    Songoku999 Newbie

    Reputations:
    0
    Messages:
    5
    Likes Received:
    0
    Trophy Points:
    5
    Tried it on my extracted vBios (using UEFI Tool) from Acer VN7-593G (1060) System Bios-> Unsupported Model GP107 with Bios Version shown.
    Is there any chance for a mod? Is Prema offering vBios mod for Pascal?
     
  8. Meaker@Sager

    Meaker@Sager Company Representative

    Reputations:
    7,623
    Messages:
    47,922
    Likes Received:
    12,940
    Trophy Points:
    931
    Not that I am aware of at the moment.
     
  9. Songoku999

    Songoku999 Newbie

    Reputations:
    0
    Messages:
    5
    Likes Received:
    0
    Trophy Points:
    5
    And does Prema offer vBios mod services of Pascal GPUs?
    One more thing that's odd is that my Notebook has a GP106 GTX1060 and I found only 1 vBios in System Bios with UEFI tool that reads GP107 in header.
    Size is 161kb.
     
  10. Falkentyne

    Falkentyne Notebook Prophet

    Reputations:
    6,311
    Messages:
    5,107
    Likes Received:
    6,888
    Trophy Points:
    681
    This probably concerns about 5% of users who used mods here, but that 5% should still be aware of something.

    Increasing power limits by the change of the advanced rail settings (presets) with this tool while it works great on AC power, actually completely screws up the way the system throttles on battery power.
    While the Nvidia vbios still throttles the GPU *hard* on battery power, if you reduce the TDP down to 115W (default) via MSI AB slider, and then run on battery power with the rail changes, the throttling point on battery is actually *STILL* raised. Before my laptop repeatedly shut off by itself, I was greeted to my GTX 1070 pulling 65W on battery power (!!!) even with the TDP forcibly set to 115W default. The first advanced rail was set to 19,200, but the problem had actually originally happened with the basic "preset" way back for 16,200 and 151-170W slider. I remember trying to play Tekken 7 on Battery power last year (basic preset, 1st rail at 16,200 rather than the default 14,500, if that was the default) and the laptop simply shut off after a little bit of gaming, and I thought nothing of it at the time. But now I was able to find out what's going on.

    On a 75W battery, the GPU should NEVER be allowed to pull 65W by itself! The EC (Embedded Controller) was shutting off the battery due to overdraw (rather quickly).
    I had to set the MSI AB TDP Slider to 35% (even 50%, which is 75W TDP, wasn't enough) to keep the GPU from drawing more than 50W.

    Something silly, but occasionally people may be stuck without an AC charger and may want to game on a TDP modded video card. Just something interesting to remember!
    Again everyone's specifications are different and no two vbioses or competing systems are created identically. But keep that in mind. Game on!
     
    raz8020 and Robbo99999 like this.
  11. sirgeorge

    sirgeorge Notebook Consultant

    Reputations:
    138
    Messages:
    108
    Likes Received:
    135
    Trophy Points:
    56
    @Coolane

    Any chance you could release the source code for this?
     
Loading...

Share This Page