ThrottleStop - Overclocking Dell Precision M6800

Discussion in 'Hardware Components and Aftermarket Upgrades' started by derei, Jan 7, 2018.

  1. derei

    derei Notebook Geek

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    Overclocking your CPU, Opening your machine, tampering with hardware in any way, may VOID your warranty. It's all up to your skills to continue from here and you must take responsibility for all the potential damage it may occur (overclocking helds a potential of short or long term damage to CPU, mainboard, or other components).

    This tutorial assumes you have some (elementary, at least) knowledge about ThrottleStop. If not, please start with this tutorial:
    Also, check this forum too:

    I own a Dell Precision M6800 laptop equipped with i7-4900MQ Haswell CPU. This CPU runs at 2.8GHz Non-Turbo and has a 3.2GHz Long-Term Turbo frequency with a peak of 3.8GHz (for 23 seconds). Its TDP is 47W (with a burst of 58.75W).
    Using ThrottleStop, I managed to make this CPU to run at 3.9GHz constantly with all 4 cores active and 4GHz when 1 or 2 cores were active.
    Note that the temperatures went quite high on full load (around 92°C), but that is within parameters for this machine, as the fans kick in full speed (~4000rpm) only after the threshold of 91°C is reached. So, as long as you will be able to keep CPU temperature up to 92°C, everything is alright. Even beyond this (93°C-94°C) is still okay, but this may be pushing the cooling system a bit too much, so you will need to keep a close eye on temperature. My CPU had thermal throttling at 97°C.

    STEP 1 - Preparing the Hardware
    Whilst the stock thermal paste in M6800 is doing okay for standard use, it won't be enough for what's coming on that CPU.
    My suggestion would be to use Liquid Metal, as it has the best thermal conductivity from everything is available. If you aren't confident enough with your skills, go for the best thermal paste available.
    Beware that any Liquid Metal compound can jump on the mainboard, causing potential damage to the electricals! It can also migrate from the CPU die if you apply too much and cause irreversible damage (is metal - it conducts electricity!).
    Also, (most) Liquid Metal TIMs are alloys based on Gallium, a metal with a very low melting point (27°C) and which will combine with Aluminum, creating a very brittle alloy which will practically damage the aluminum part completely and in extent can damage your machine. So, NO DIRECT CONTACT WITH ALUMINUM PARTS!

    I used Thermal Grizzly Conductonaut which is stated on their website to have 73 W/mk thermal conductivity (double than Coollaboratory's equivalent) - please take this data with a grain of salt, as it could be inflated values for marketing purposes.

    In order to learn how to open your laptop, I suggest to reffer to your laptop's User Manual. Usually it can be found on manufacturer's page.

    -the original TIM that came from factory had a certain thickness (i assume somewhere to around 0.5mm), which in conjunction with spring-loaded heatsink plate, ensured enough pressure on CPU DIE. Applying anything thinner (like a very thin layer of liquid metal) will drastically reduce the heat transfer performance.

    The solution for that is to add a spacer. I used 2 copper plates 0.2mm thick, coated on both sides with Conductonaut. I suggest you use one 0.4mm-0.5mm thick plate, if you have. I only had 0.2mm, that's why I had to use two stacked.
    Clean the copper plates to perfection, to remove any oxidation. After you are sure is clean, wipe it properly with a cotton bud and Isopropyl Alcohol (99.99%), to remove any left residue. You will know is clean when the cotton doesn't become black anymore.
    Make sure you only add the minimum quantity of Liquid Metal to ensure firm and complete contact between plates and it won't squirt out when the plates are pressed tight. With several tries you will get the feel of it (hopefully).

    Another (very) important step is to make sure you protect any exposed electrical contacts that may come in touch with Liquid Metal.
    To ensure this, I did the following:
    -on all resistors on top of the CPU PCB I added a tiny drop of Nail Polish (I used transparent). Not much, just enough to create a thin coating. I used a plastic tip to touch a bit of varnish on top of each. A brush would apply too much.
    -second, as a redundant measure, I applied a 0.5mm Thermal Pad over the entire surface of CPU's PCB, that would limit the gap between the PCB and Heatsink, reducing the chance of any Liquid Metal particle to migrate on the Mainboard from the CPU DIE. If any drop would go out, it's most likely to be caugth by the sticky surface of the thermal pad and because the gap left is so small, the surface tension would also play a role here.

    Apply the Liquid Metal first on the Heatsink, using the cotton bud provided in Conductonaut package. Then, with the same bud, apply on the CPU DIE, pressing gently. If you add too much on the heatsink, is easier to remove, but from the CPU may be more difficult and increase the risk of messing the mainboard, which may turn in a nightmare.

    If you want to cut a similar template for your own use, here are the dimensions that I used (for i7-4900MQ Haswell):

    As long as you are here with your laptop opened, you may as well optimize the TIM on your GPU... but that's optional.

    -Now that you maximized the heat transfer between the CPU and heatsink, you must be aware that the next major limitation is the heatsink itself. You will soon notice it can't drain all the heat the cpu is producing and the temperature will slowly raise to alarming levels if the voltage is not managed properly.

    STEP2 - Overclocking using ThrottleStop
    First, download ThrottleStop from here:

    Before starting the overclock process, is recommended to upgrade cpu's microcode. It's said it can improve efficiency and thus reducing themperature and power consumption.
    Links for reference:

    What I also did, was to unlock some parts in the BIOS, which gave me access to control the Max Current. Whilst this feature won't really affect your system by increasing it (again, due TDP), you will see it working if you decrease it (your cpu will throttle - EDP CURRENT).
    This became handy later on, when I had to make sure there won't be any current limitation while using PowerCut feature of TS.
    To unlock BIOS, use this reference:
    -note, this will also allow you to get access to other sensitive parts in BIOS, so you can alter it in more advanced ways. For more details, read the post in the link above.

    Now, assuming you didn't damage your laptop and you are ready to proceed, let's focus on overclocking (the most difficult part has passed, all you need now is patience and dedication).
    For configuring profiles and other settings in TS, check the first links in this tutorial. I will not focus on those aspects, as you can find that information already prepared.

    Unlike desktop CPUs, in our case we will UNDERVOLT the CPU in order to increase frequency and performance. This means we will reduce the voltage whilst increasing frequency until a very fine balance is achieved and the CPU runs at its peak without overheating (too much).

    1. Start by setting your desired multiplier target. I recommend you to start with something less demanding (39-39-38-38) and once you learn how TS works, you can go higher and to explore the limits of your machine. Mine can do 40-40-39-39, but I found it rather unstable, so I capped it to 40-39-39-39.

    The Cache max multiplier should be less than Core multiplier. I set mine to 36x whilst I had 39x for all 4 cores active. The reason for this is if your CPU throttles and the Cache frequency is higher, the cpu will become unstable. Also, the Cache frequency doesn't affect performance in a noticeable way.

    2. Reduce the Voltage Offset for CPU Core and CPU Cache in small steps, testing every time.

    When undervolting, the CPU will more likely become unstable on light-duty tasks, so running a stressing tool like Prime95 or Linpak will not be a very reliable test. Use the TS Bench included in ThrottleStop and also do some light-duty activities (web browsing).
    What I used, was to do 3D Rendering with SketchUp and Twilight Render. It proven the best combination for combined stress, as it was getting the CPU from high load to low load, from one core, to all cores during a rendering session, so I got all conditions (in can tell you more how to use these, if you want).
    This setup allowed me to get BSOD in time of minutes for voltage configs that ran for days on high load. Believe it or not, but in overclocking, BSOD is your friend, as it can tell you about the direction you're taking and can give a clue of what do to next.

    Also, make sure you run on AC when overclocking (power supply, NOT battery!!) and your Power Plan is NOT set on Maximum Performance. Why? Because on Maximum Performance, your CPU will be forced to run at 100%, which is okay if you never intend to allow it to step-down. But if you OC in this mode, you may end up with a setting that will make your CPU very unstable once it enters in a power-save state. So, best is to run it on a Power Plan which allows your CPU to change from minimum multiplier (8x) to the maximum you set up in TS (this is usually the Balanced Power Plan). This way, is more likely to catch any crash and to be able to correct the voltage accordingly.

    3. See how low you can go with CPU Core Offset while keeping it stable. I was able to go to around -90mV.
    Remember to keep CPU Core and CPU Cache Voltage Offsets at the same values.
    If you monitor Limit Reasons, you will see a lot of triggering especially in Power Limit (PL1 and PL2), but this is nothing to be worried now.
    If you get EDP CURRENT a lot, then you should increase the Current Limit.
    Anyway, whilst you still run under TDP, there isn't much you can do yet, so even increasing Current Limit may not do anything for now.

    4. If you reach a point where the PC became unstable (freeze or BSOD), roll-back a bit the Voltage Offset and test again. Once you got your laptop stable you can either stop here, if you are happy with the results, or continue reading to achieve even greater results (which I did).

    STEP 3 - Bypassing the TDP
    1. Advanced feature (not for the faint-hearted): PowerCut!. This feature is exploiting a bug in Intel Microcode which prevents the CPU to report the actual power consumption and therefore it "fools" the TDP and avoids P1 and P2 throttling.
    The downside of this measure is the CPU can go crazy hot, because there is nothing to limit the power draw anymore. So, make sure your cooling system can handle it and your power supply can too...
    REMEMBER: Don't enable PowerCut while running on battery, or you may damage the battery or even set it on fire, if it gets too hot.

    2. We will start by setting the VCCIN voltage to a fixed value (can start with 1.75V - 1.8V) and hit Apply. This is the "main" voltage that gets fed into the CPU and from which all parts of the CPU take their share. This is also the voltage value most responsible to heating. So, our long-term goal will be to reduce VCCIN as much as possible, in order to keep temperature under control.
    I was told that minimum reported stable values for Haswell were around 1.4V, but mine runs at 1.3701V right now.

    Remember that you just set the Voltage Offset for CPU Core and Cache to a very low value, which means you may encounter a crash very soon the moment you tamper with VCCIN. If it already happened, don't panic: just reverse a bit of the Voltage Offset (for both Core and Cache) until you get the machine stable again.

    Voltage Offset will apply an offset to voltage value for the entire curve of voltages (regulated by the cpu based on load and frequency). So, if your input voltage (VCCIN) is already very low, applying a big offset on it, may push it below the safe value for your CPU.

    3. Enable PowerCut and test, to see frequency and temperature. Monitor temperature carefully, as it may raise very quickly.

    1. Close any background programs (check tray too) which may keep your CPU busy. Anyway, when OC-ing you don't need many programs running around.
    2. Set VCCIN to a desired value and hit Apply.
    3. Check PowerCut checkbox, but DO NOT hit APPLY just yet!
    4. Monitor the CPU Power draw and when it goes to idle and power consumption is low (eg. 4W-7W, in my case), hit Apply! This will make sure your CPU reports a very low consumption even on high load. It will also lock VCCIN value to the one you just set.
    From this moment on, the only reference you have is the CPU temperature. And you should keep an eye on it like a hawk!

    1. Uncheck PowerCut
    2. Set VCCIN to Default (move slider all the way to the left)
    3. Put your machine to Sleep, then resume. PowerCut will be disabled and VCCIN unlocked.

    OBS: If you DO NOT set VCCIN to Default, then when the machine will resume from Sleep, the value of VCCIN will remain the one you last set. This is not a bad thing if you want to continue from that point. It's really up to you what do you want to do.

    4. Now, that you know how to work with PowerCut, is time to start tweaking VCCIN and Voltage Offset for Core and Cache.
    So, your goal now is to have VCCIN to the lowest whilst also having Voltage Offset as low as it permits (remember to always lower the value for CPU Cache Voltage Ofsset too). To do so, you will begin by reducing VCCIN in small steps, testing every time until the laptop will either freeze or crash. When that happens, reduce the Voltage Offset (roll-back a bit) and then continue to lower VCCIN more.

    You won't be able to go very low with VCCIN, because that is the main voltage fed to the CPU, from which all other voltages are collected. So, even if you put your Voltage Offset back to Default, there is still a limit for VCCIN, which cannot be breached.

    One trick I observed on my machine that can make things faster is to enable PowerCut (this will Lock the VCCIN value), then put the laptop to Sleep and resume. Run TS and now you will have PowerCut Enabled, but VCCIN unlocked.
    If this trick works for you (It seems M6800 has some features unprotected/unlocked in BIOS which allowed this trick. It may not work for other machines), you will also notice TS reporting REAL power draw (my CPU reported even 86W and more).

    So, if the above works, you will be able to adjust VCCIN on the fly and test it until it crashes. Beware, once you got BSOD or the machine froze and you need to reset, PowerCut will be disabled again and you will have to follow the steps to re-enable it.

    STEP4 - Final Settings
    1. Once you are happy with the final results, don't forget to set up Alarms, Battery Profile, other profiles as you wish (make sure to have a Safe profile too, to wich TS will switch in case of overheating). And other settings for your long-term TS use.
    It's recommended to set up TS to run minimized in System Tray and if you want you can even enable it to show temperatures and CPU multiplier in Tray. ThrottleStop has minimal impact on system resources (on my machine it takes ~3.8MB RAM and CPU usage is unnoticeable).

    2. Remember that TS will have PowerCut disabled every time you resume from Sleep and is also best to check it after you power on your machine too, in case you wish to run PowerCut.

    3. Also, when running ThrottleStop:
    -make sure you have a Battery Profile properly configured, plus TS properly configured to switch on that profile. You want this to avoid running the CPU overclocked when on battery. The power drain may be too much for a battery to handle it properly.
    -especially when runing PowerCut, make sure your machine is well ventilated (periodically check it for dust too), monitor temperatures and as stated above: make sure you run on AC!

    Many thanks to @unclewebb , the creator of ThrottleStop. Without his constant support I would have not been able to learn how to use TS or to share this tutorial with you guys!

    I hope this helps someone and... Good Luck OC-ing!
    Last edited: Jan 8, 2018
    tranquil911, pressing, bennyg and 3 others like this.
  2. pressing

    pressing Notebook Deity

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    Great mods and writeup.

    You might boost fan intake a bit by drilling several larger holes in the case bottom under the fans.
    Obvioulsy Dell provided a grille there now but every bit counts. A few thoughts:

    1- I used a Milwaukee Hole Dozer on my MacBook Pro and recommend you do the same.*

    2- I also lift up the back of the laptop 1-2cm to allow more air to enter the laptop.

    3- You might also use some Kapton tape (or high temp electrical tape) to create a more efficient channel inside the laptop for air to flow from the fan past the radiators without leakage. @iunlock has some good photos of this on other laptops.

    MacBook Pro vs. Hole Dozer below:

    * I added some non-conductive fibreglass screen door material to provide some minimal protection.

    Last edited: Jan 8, 2018
  3. derei

    derei Notebook Geek

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    My mistake guys, I set the album holding the images as private, so there were complaints the images are not showing up. All should be fine now.
    pressing likes this.

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