Precision 5520 thermal/power Throttling

Discussion in 'Portable & Small Form Factor' started by wwwww, Dec 4, 2017.

  1. wwwww

    wwwww Member

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    I've had issues with this laptop overheating since day 1, it's been 4 months, 2 motherboard and 2 heatsink assembly replacements later and it still overheats. Google says this is a common issue and I was wondering they're all like this (throttle down to 800MHz after a minute or so of load) or they're just replacing my motherboard with previous warranty returns which have the same fault?

    I really don't want to have to switch to another model as it definitely won't be a Dell and I already bought two Dell docks for it but if it's not fixable I have to.

    So does anyone have a 5520 that doesn't throttle under load while on AC power?
     
  2. EvilGenius

    EvilGenius Member

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    At this point you've had a series of major failures, under Australian consumer law you're entitled to a refund or full replacement. Push for it, hard.
     
  3. OP
    OP
    wwwww

    wwwww Member

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    I've asked them for a full replacement and they're still deciding. I don't really want a refund unless it's unfixable (i.e. they're all like that) because I've already forked out for docks and other accessories.

    Or a better question is this normal behaviour for laptops? Previously I've been lugging around a HP z440 (it's for software demonstrations, even though spec-wise the Dell is faster it just can't handle it because of the throttling which just makes our software look bad). Are there any laptops which can run at their full rated speeds sustained?
     
  4. EvilGenius

    EvilGenius Member

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    I have an older Dell Precision M6800, 17 inch mid-high spec machine. Beefy cpu and gpu. I can game for hours or crunch video etc. It gets bloody hot underneath if I just sit it on a dock so I generally use a little usb fan to blow underneath, or if I'm off the dock I use a laptop cooling pad. To my knowledge I've never had it thermally throttle even on a flat desk without additional cooling, but usually in those situations I'm not working it as hard either.

    How's the fan profile on yours? Are they screaming away before it throttles or is it staying relatively quiet?
     
  5. OP
    OP
    wwwww

    wwwww Member

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    The fan goes on full blast once it reaches 90 degrees and starts thermal throttling.

    Once it slows down due to power throttling the fan speed slows down and only returns to full blast when it exceeds 90 degrees again.

    I just did some CPU+GPU load testing

    The CPU never reached its rated speed (i.e. it throttles before the speed builds up), it was power throttling the whole time under load and thermally throttling intermittently when it exceeded 90 degrees. Average clock speed was 2462MHz vs a rated 3GHz - 3.6GHz for the chip (although the turbo goes to 4GHz, under 4-core load it isn't designed to exceed 3.6GHz), minimum clock speed was 800MHz.

    The GPU did better, it took 130 seconds before it went into permanent throttling, there was intermittent power throttling beforehand but at the t=130 mark it was permanently thermally throttling with a temp between 76 and 78 degrees.

    The system feels extremely sluggish even after I took the load off(as in just typing here is very delayed, windows freezes for seconds just dragging a file on the desktop, etc), although it's still power throttling (this takes a long time to settle), I suspect the SSD is throttling also, it's the Samsung 960pro equivalent.

    From what I've read about this, the VRM overheats so the firmware reduces the power allocated to CPU/GPU to keep the system stable, there seems to be cooling mod for the VRM which apparently rectifies the issue but I'm not keen on modding a $5k laptop just to get it to run at its rated specs.
     
    Last edited: Dec 5, 2017
  6. EvilGenius

    EvilGenius Member

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    The fans should be reaching full speed well before thermal throttling.. There's a dell precision optimiser app that is part of the driver package, it puts a heap of garbage power management crap on there. Do you have that installed? If so I'd pull it off and see if you can get the fans to kick in earlier.
     
  7. OP
    OP
    wwwww

    wwwww Member

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    I don't have any of the Dell garbage installed (except drivers).

    Another potential issue is that the fan isn't running at full speed when the CPU is not particularly hot but the VRM is (when there's power throttling but no thermal throttling) which would explain why it takes ages to get back to normal after a bit of load.

    This could be something helped with some better written firmware but I'm on the latest BIOS as is.

    Either way this won't fully fix the problem as even with the fans on full blast it can't run at stock clocks.
     
    Last edited: Dec 5, 2017
  8. EvilGenius

    EvilGenius Member

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    Short of modding it then yeah.. I'd be pushing for the replacement and hoping maybe the new one is better.

    Time to break out the buzzwords. Australian consumer guarantees, ACCC, industry ombudsman, blah blah. Clearly the device you have isn't fit for purpose.
     
  9. OP
    OP
    wwwww

    wwwww Member

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    Yeah that's the next step but I'm trying to figure out if this is even fixable or if it's a fault in all of them as I've already had two m/b replacements without much luck.
     
  10. EvilGenius

    EvilGenius Member

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    I wouldn't think it's an 'all of them' problem. The amount of these things out there would have created a far larger story already if it was an every single one problem I would have thought.

    Another option for you is to have them swap it with the 17" model. Thermal design on the 17" should be significantly better, given it's designed to take far beefier graphics and has a lot more room for separate cooling systems. Sacrifice a little bit of portability, but sounds like you really need the grunt so it might be worth it.
     
  11. OP
    OP
    wwwww

    wwwww Member

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    Hmm possibly but throttling issues aren't something you notice unless you run it under load, even then, unless you run the Intel utility you'd just think it was running slow which could be blamed on software.

    I thought about the 17" but if I have to send it back I'd prefer to switch to a HP Zbook, the whole support experience with Dell has been a series of delays, unfulfilled callbacks and "next day" repair jobs that take weeks.
     
  12. EvilGenius

    EvilGenius Member

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    I was thinking more along the lines of they can send you a new 17" and collect your 15" from you, least they can do with what they've put you through so far. That option means you don't lose your investment in the peripherals and don't have any downtime. Would take a bit of wrangling to make happen, but it'd probably be what I'd push for at this point.

    Did you get standard warranty or prosupport with it?
     
  13. OP
    OP
    wwwww

    wwwww Member

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    Just the basic warranty.

    They just replaced the mobo again (this is mobo 4) and this one is looking promising. Ran Intel's diagnostics and it only thermally throttled a little and for moments at a time which should be good enougg, I'll see how it goes in the field, ambient temp will be a bit higher.

    They gave me a new one this time, previous ones were refurbished.
     
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