Precision M4800 CPU upgrade, TDP concerns

Excellent, keep us posted.
Apart from you I am not having much luck with the thermal pads.
My order got canceled a few minutes ago from another vendor and going directly to the main distributor it says "delivery date unknown" ...so I have to wait for god how long until I can permanently replace my thermal pads.

https://www.alphacool.com/shop/ther...rmal-pad-11w/mk-120x20x1-5mm-2-stueck?c=20701

A full square is available but for double the price
https://www.alphacool.com/shop/ther...icht-thermal-pad-11w/mk-100x100x1-5mm?c=20701

1mm is available but I would rather have that extra thickness
https://www.alphacool.com/shop/ther...hermal-pad-11w/mk-120x20x1mm-2-stueck?c=20701

Original part number is UP755
https://www.dell.com/en-us/work/sho...-mobile-workstations/apd/up755/pc-accessories
But I can't find any original spec for the thickness and I am not willing to tear down the computer just to measure.
But I base my assumption on that the existing thermal pads are seriously dented and won't recover their original shape/thickness.
If its too thick it will compress slightly and 0,5mm is within specs for compression so its not a big deal.
I rather buy too thick than too thin.
I eyeballed with my caliper and there is no way its 1mm and 2mm is to thick my guess is that it 1.5mm is the sweet spot.

Manufacturer of Alphacool eisschicht is FujiPoly SARCON XR-e
http://www.osco.uk.com/userfiles/download/Thermal Material/Discontinued Thermal Materials/SARCON_XR-E Data Sheet.pdf

Other alternative is to buy the Thermal Grizzly Minus Pad 8
https://www.ebay.com/itm/Thermal-Gr...-x-120mm-x-1-5mm/182539105758?epid=1542607233
But then it comes only in 1pc and I need two and Ebay don't handle orders such as that so I have to pay for shipping twice.
And its specced at 8W/mK instead of 11W/mK ..way more than I probably need I would like to match the cooling paste conductivity.

Edit:
I bought two of the Thermal Grizzly, as linked from ebay.
They have a website so I ordered from there instead
https://www.cclonline.com/product/2...zly-Minus-Pad-8-20mm-x-120mm-x-1-5mm/CLR1509/
None of the local vendors have the correct thickness in stock from any brand so I am forced to buy from overseas..

 

I got the Thermal Grizzly Minus Pad 8 thermal pads in the mail today and installed them this evening.
When I teared down the computer and measured the existing thermal pads with my caliper luckily they actually are 1,5mm thick so I did order the correct thickness!

I used up one and a half strip so you do need to buy two packs for this job if you want to do this yourself unless you can get your hands on the fuji 2 pack if it will be back in stock in the future.
1,5mm thickness is rare to come in 2 pack.

Note
I cut the thermal pads bigger than the original one to maximize surface area and thus maximizing the thermal performance.

Starting with the cpu:
The chipset or whatever the small rectangular chips is I cut a whole width of the thermal pad as long as the whole chip itself to overlap the die because the heatsink overlaps this whole area so it would only benefit to make it as big as possible.
And I didn't have to waste material by trimming it to a smaller width.

The bottom left strip I also made wider than the original because it did not cover the whole chip area.
And because the solid cap was in the way I cut a small piece off the end to make it fit in there so I didn't have to make several separate strips.

The bottom right strip I also cut wider than the original.
But this was the leftover from the previous strip, so I just used what I had left from that trim as it did not touch the white plastic cpu locking mechanism I just placed it there and it fits fine where it is.

The orange tape is Kapton tape to prevent the thermal paste to smear on the other components.
It just make it easier to clean up in the future when the thermal paste needs to be replaced.
I believe it is 20mm wide.. it was years ago I bought the rolls I have, they are expensive but they last for a really long time.




The gpu:
I forgot to take a picture and only realized it when I already smeared cooling paste and fastened all the screws.
But anyways..

Starting to the right I took the remaining strip of the first one I had and placed it at the right end of the card.
Originally this is made up of three or so thermal pads in different sizes but its easier to keep it simple and have just one spanning the entire length of the graphics card.
There are inductor and other power related chips in this area so it is very important to cool this area well.
Notice that there is a positioning leg to the right of number 3 screw.
To make the strip not sit proud of the memory chips to the left I cut a small notch in the strip so that the leg would fit and the thermal pad would still sit in the right location.

To the left of the previous strip is two individual strips, one for each memory chip cut to fit onto the entire span of the chip.
Originally they were a little to small to cover the entire chip.

Above the heatsink is the same thing.
Two thermal pads that cover the other two memory chips.
Notice that the heatsink only cover half of the chips but I still cut the pads to cover the whole chip.

Down below between screw number 4 and number 1 I placed one more small strip to cover a small component.
Originally there is no thermal pad there but I had a little scratch over so why not.
It cant hurt.

Also around the gpu die is Kapton tape same as I have on the cpu to make it easier to clean off the old thermal paste.





I ran furmark stress test on the gpu and it topped at 65c with the fan not even stressing maxing out on 2600rpm, before it would just roar like an airplane.
I ran a cpu Prime 95 stress test and the cpu topped out on 85c with the cpu fan also not stressing at all just one time revving up to 3100rpm and it took down the cpu temps to 76c.

In idle I see an even bigger improvement.
Windows 10 is usually very active in the background even that I have uninstalled cortana and defender to have it calm down the fans rarely stops for long periods.
The cpu fan actually stops many times, it has never done this before on Windows 10.
It can run for 3 min and then just stop until I start using it again.
When typing this it has stopped 3 times and just now it spun down..amazing!
Cpu temps are at the low 50 to 46c when it stops and stays at 50 to 57c until the cpu fan starts spinning again.

The computer also feels cooler to the touch underneath just behind the docking port.
This area was very hot to the touch before and I did not like this.
Now its just lukewarm to the touch.
And that would be the heat from the gpu seeping through by convection now instead being transferred more efficiently through the heatsink instead.

 

I received the GPU fan. It is Delta.

Left = AVC, right = Delta


Left = AVC, right = Delta


Delta's distinctive "raised cone" fins. I'm not sure about the engineering but it at least looks like some more thought and design went into this fan compared to the alternatives.


Installed.


I haven't had time to run any temperature tests yet. Last night I was working on my failed Quadro P5000 install.

My goal for swapping the fans was more to lower the noise than to lower the temperature. However, since discovering that manual/custom fan control is possible in between when I ordered these and when I got them, that's not really an issue anymore.

 

Ok, wow, this fan makes a difference.

Last weekend I worked on a custom fan profile with SpeedFan for the M6700. When looking at graphics, under load (3DMark running a Fire Strike test 2 in a loop), with the AVC fan, running at medium it would quickly climb to 85C within two or three minutes. The fan speed would kick to high at this point and it would stabilize at around 82/83C.

Under the same conditions with the Delta fan, with the fan running at medium it took almost 10 minutes for the GPU temperature to reach 85C. The fan speed then kicked to high and the temperature stabilized at 75/76C. Just putting my hand behind the vent I can tell that considerably more air is coming out. And it's not as loud either.

Because it took so long for the temperature to reach 85C, increasing the temperature at which I kick the fan up to high, wondering where it would stabilize. Unfortunately the card starts throttling when it hits around 87C, and it did hit that, so I have to keep the threshold at 85.

Still waiting for the CPU fan to arrive.

 

Nice! That is a difference.

I didn't give much thought to fan control because the run levels are lacking so to speak.
I come from thinkpads and manual controls on stationary computers and being able to control rpm to a specific temperature with tpfancontrol or thinkfan. On Dell there is Off, Low, Medium and Maxium speed!....
And it only works on Windows 10, on Windows 7 I get a blue screen as soon as I try to take control over the EC.

The Low rpm does not match up with the 2100rpm that the EC spins the cpu fan on when automatically running the fan and the Medium is too fast and loud. For me its not worth the hassle to control the fans this way.
I don't know if the M6700 has more fine control over the fans? But on the M4800 its really not that impressive.
No one has successfully hacked the M4800 bios and figured out the ec circuit.
There has been some tries and partly successful progress but this requires soldering pins on the motherboard and many other special procedures.
And I discovered that on Linux mint I could not get the gpu fan to stop even with the Nvidia drivers installed and set to the intel gpu. And there really are no fan control for modern dell computers on linux.
The last resort which I have done before is a 5v temperature controlled fan speed controller and a 55c bi-metal switch to control the on and off running off one of the usb ports with two cables soldered to one port.
So that is why I have gone to such length to reduce temperatures and find the absolute best cooling solution.

• The most powerful cpu and gpu fans (sent message to cmyhub on aliexpress to perhaps get a hold of the delta gpu fan)
• The best cooling paste that pass RoHS: Thermal Grizzly Hydronaut (7,8g)
• The best cooling pad: FujiPoly SARCON XR-e 11w...(you can go higher but expect to pay ~70-80usd for one 17w strip...not worth it).
  But because my order was canceled and with no delivery date I went with 8w Thermal Grizzly Minus Pad 8
• Enlarging the wholes in the bottom panel grill to 1.5mm
• Putting 9mm square rubber feet under the computer to let more air in underneath.
• Using the computer in the Dell E-Port Plus dock when on the desk that elevates the computer even higher.
  
  Going to great lengths to reduce the background processes in Windows 10:
• I uninstalled cortana: https://winaero.com/blog/how-to-uninstall-and-remove-cortana-in-windows-10/
• I uninstalled Defender: https://teamos-hkrg.com/index.php?threads/remove-windows-defender-version-3-0-teamos.72189/
• I disabled a bunch of services and used tools to further make Windows 10 LTSC to calm down:
• Blackbird https://www.getblackbird.net/
• O&O ShutUp10: https://www.oo-software.com/en/shutup10
• W10Privacy: https://www.winprivacy.de/english-home/
• WPD: https://wpd.app/
• A host file with entries to limit many phone home's:
• https://paste.ubuntu.com/p/JT5VbDrhHx/
  All the software I use runs just fine I don't have any issue at all so the things above does not interfere with functionality.

The delta fans are in another world when it comes to quality.
The AVC fans I have had trough the years even the gold series feels plasticy and light and the blades bend really easy and their bearings are noisy even in low rpms. I have a bigger love for Delta and NMB-MAT fans.

The "raised cone" fins on the Delta fan first is about surface area.
You can think of it as an air filter that has a paper folded in many many ridges and if you would unfold the paper it would be maybe a hounded times longer than in its folded state.
While the AVC fan has strait blades mounted on an angle it has only that surface area and only that to push the air around the inside the frame while the Delta fan has many times that surface area creating a higher static pressure and overall pushes more air too.
The design optimizes the suction in the various areas in the fan as it is a centrifuge rather than an axial.
Also the increased amount of impellers on the Delta fan contributes to increased performance.

Another advantage is that with these design modifications you can by math formulas and simulations cancel out the noise created by turbulence and air piling up on the fins making the overall acoustic much more tolerable.

The avc fans are all concave meaning that the middle is like a bowl and the centrifuge force pushes the air towards the end where the impellers are higher and there it get sucked in.
I am no expert but I figure that this concave design creates a large bubble of turbulence making a lot of noise when the fan revs up..that's just my theory

 

Indeed, with the EC disabled there are just three fan speeds available on the M6700: 0 RPM, 2500 RPM, and 4900 RPM. With the EC running the fans it has more granular control, but you can't customize how it works other than selecting from one of four thermal profiles in the power settings area (default/cool/quiet/performance).

My gripe is simply that the M6700's default fan control is dumb. I've disliked this since I first got the M6700 way back in 20122. It cycles the fans between 0 and 2100 RPM regularly and they don't turn on "gracefully", when they turn on they briefly whir way up above the low 2100 RPM speed before settling down. That makes a distracting sound that I'd rather not have. Plus, it runs the GPU fan when only the CPU is under load, which makes no sense, there is no heat pipe from the CPU to the GPU fan. It also changes the fan speed levels constantly, ramping them up under even a modest CPU load (i.e. scrolling too much in the web browser causes the fans to speed up), unless I have it set to the "quiet" thermal profile, which caps the CPU frequency to around 2.3 GHz. Another thing is, if I put the system under load for an extended time, when the load is done the fans would still be running full blast for several minutes before slowing down, even though it is just a matter of seconds for the temperature to drop (especially on the CPU side).

With custom control I just leave the fan on "medium" (2500 RPM) all of the time (unless the temperature reaches 85C which would only happen under a pretty serious load). I don't find it to be loud at all. Maybe the larger fan in the 17" makes less noise? I don't have the CPU frequency capped anymore. The fans do their job (GPU fan doesn't kick on under CPU load and vice versa). Fans slow down almost immediately after the load goes away.

I've used the M4800, 7510, and 7530 and I don't have this problem on those machines. I think they fixed it in the M4800/M6800 and up, the default fan behavior makes a lot more sense and hasn't annoyed me. (Well, it's not perfect, they still run the GPU fan when it doesn't need to be run.) I set up a custom fan profile for my 7530 and only used it for a short time before reverting to EC control of the fans, because it does it better than anything I can do with just three fan speed options.

 

They joined the cpu and gpu heatsink again on the newer precisions to give an overall better cooling solution.
So that might be why both fans are spinning even if the gpu is not be active.

To me it actually was one of the selling point because I do not want the other fan to spin when it don't need to.
But the gpu fan can start even if the gpu is not active if the area around the gpu starts heating up.
So even the M4800 does that with seperate heatsinks.
It haven't done so since I changed the thermal pads, it did do so when compressing 7z files with the avc fan in it.
The gpu fan would spin up for a while then shut off again and repeat this every few minutes.

 

My CPU fan finally arrived. I was promised that it would be Delta. But what I actually got was...




"DBJBA" ...?

One of the fan blades is damaged as well (you can sort of see on the right side of the second picture). Not going to install it. I'm not going to return it — I already had issues with communicating with the seller; it was returned to them once because they did something wrong with the address, and they sent the wrong tracking number twice... It's just not worth the hassle for the cost. I purchased another Delta fan on eBay but the sale was cancelled after a few hours, I guess they don't have it in stock. I can't find any more for sale. I'll have to keep looking periodically.

 

By the look of the impeller blades and the colors of the wires it looks like a rebranded AVC fan or reverse engineered(?)..the chinese are good at this (not quality wise but legally)
I tend to lean towards reverse engineered because it looks like it has no fiber glass and only abs.
The AVC original blades are very rigid and does not brake easily like in the picture.
The injection molding releases have rough cuts on the back while a real AVC fan are a lot finer.
If its recycled abs which is common in china its even worse because abs does not age very good when reused, it looses a lot of strength.
But this is the first time I have seen a real life example of a rebrand.
Some years back they only did this in Photoshop to hide the labels in the ad images so that they would not get trouble with lawyers and when you received the parcel the label would read avc or delta or whatever the brand is.
This confirmed my doubts about the ads with this DBJBA label.

I too have difficulty communicating with the seller on Aliexpress having the delta gpu fan.
They have the impression that I am looking for a same brand that I already have asking for the part number of the gpu fan.
I gave them images even that I only want confirmation that the images are what I will receive and not just an image for reference.
But this seems hard to communicate that to them..and it has been chinese new year so there has been some weeks of silence.

 

I decided to look at other models. I couldn't find any Delta M6600 CPU fans. I started looking at M6800 GPU fans. (The fan roles are swapped in the M6800 compared to the M6700 and M6600, though they are in the same positions, the GPU fan is the large one.) It was easy to find Delta fans for this, there are multiple listed on eBay. The dimensions appear to be the same as the M6700 CPU fan. Even if it is not an exact fit, maybe I can just swap the fan outer enclosure. This one is coming from the U.S., I'll find out soon.