Precision M4800 CPU upgrade, TDP concerns

Did you find any Delta CPU and GPU fans for the M6800?

 

As mentioned, Delta GPU fans are easy to find, I ordered one yesterday and it should arrive next week. Here's another one (assuming that the picture is the actual item).
https://www.ebay.com/itm/Dell-Preci...h=item5b533b92b4:g:zP0AAOSwajRcZH2O:rk:8:pf:0

I didn't look for CPU fans, but I did just now, I easily found two (again assuming that the picture matches what you get).
https://www.ebay.com/itm/Dell-Preci...h=item1cca5dd965:g:a7kAAOSwfHBcYd2y:rk:9:pf:0
https://www.ebay.com/itm/Dell-Preci...=item56c0aa84d3:g:P0gAAOSwRYNcZH2P:rk:10:pf:0
Assuming that it matches the M6700 GPU fan (it looks the same at a glance), you could use one of those as well, I already have one that I purchased last month.

 

Ok, I got my M6800 Delta GPU fan in two days (after waiting over a month for the M6700 "DBJBA" fan).

Question:
Does M6800 GPU fan work as a M6700 CPU fan?

Answer:
Not quite... The fan enclosure shape and size is the same, but one of the screw positions is off.



Ok, this can be worked around. I took the "DBJBA" fan that I got and swapped the bottom metal plate with the M6800 Delta fan. Three of the four screw positions are the same so this worked fine.

Left = Delta, right = DBJBA, before swap


Left = Delta, right = DBJBA, after swap


Ok, it should fit now, right?



Brilliant! The Delta fan is installed.

I powered on the system and found that the CPU fan would not power on. I wasn't expecting this. The system shouldn't be able to "detect" that it is a different type of fan, it uses the standard four-pin fan connection (ground/power/sense/control). And they're all just electrical, the fan doesn't have any computational/identification capability. I reseated the fan connector and there was no change. So, I went to swap back to my original AVC fan, and then I noticed...



...The order of the colors of the wires is different between the M6700 and M6800 fans! Even though the physical connector is the same (it fits into the port on the motherboard). Ugh, Dell, why would you do this?
At least they color-coded them. On the smaller M6700 GPU fan, the wires are all black.

Going to see if I can get that glue off and rearrange the wires...

[Edit]
I got the wires swapped but it is still a no go. The fan did power on. It made a funny pulsating sound while it was running, like it was constantly switching between a high speed and a lower speed. SpeedFan could not report the RPM. Maybe I broke one of the wires when doing the swap, they are so tiny, but they look good... When rebooting I got a "fan malfunction" message from the BIOS.

I'll have to wait for a proper M6700 Delta CPU fan to appear on eBay again.

[Edit 2]
Realized that the strange fan behavior I reported would maybe happen if the "sense" and "control" lines were swapped. I swapped the blue and yellow wires. This time the fan didn't "pulsate", it ran at 100% speed constantly. SpeedFan still couldn't report the running speed.

I think that Dell isn't using the standard colors for the wires (red = power, black = ground, yellow = sense, blue = control). And either I totally bungled my wire swapping or they switched the colors in between generations as well...? Anyway, I have a M6700 Delta fan on order coming from the UK.

 

Received an actual Delta CPU fan from a UK seller. Works fine.

Unlike with the GPU fan, I'm not noticing any sort of drastic improvement with the CPU fan. Idle temperature is a few degrees cooler (fan running at 50%) and load temperature is actually a few degrees warmer (fan running at 100%). It is still able to maintain max turbo, though, and it is a bit quieter... So I'll take it.

 

Found a seller on fleabay that sells the Delta Fans for the M6800 and a few other bits and pieces for Precisions. His website sells the items cheaper versus fleabay.

ebay seller ID: cmyhub.
website: www.cmyhub.com

Not sure if legit. Will give it a try and buy some fans.

 

I am in the process of buying one or two gpu fans, it is difficult to communicate with the seller.
Any question you ask, specifically if they can confirm that it is delta branded they just tell you to look at the image.
I'm asking this because there are many sellers who has a delta fan but send an avc fan.
I'm waiting for another M4800 to arrive and I will take it apart and see what fans it has and then make my decision to buy one or two of them.

 

I'll ask him later today as I can converse in Chinese. I'll keep you posted about the outcome.

 

I did end up getting a refund for the "DBJBA" fan. I decided that I couldn't let the seller go with the deceptive messaging (confirming that the Delta fan image that they had on the auction listing was the actual item that I would receive, and then sending me something else). They insisted that the fan was a compatible replacement and should work fine and that was all that I could get out of them. After I submitted some comparison photos, eBay stepped in and gave me a courtesy refund.

I'm thinking about trying @unnoticed's trick of enlarging the fan grill holes on the CPU fan side, I've noticed a few cases where under a full multi-threaded load my clock speed is dropping from 3.5 GHz (the usual max) to around 3.42 GHz, which didn't happen with my old AVC fan, so it seems like it could use just a tiny boost. (Still would like to keep the Delta fan in, it really is quieter, a higher-pitched sort of whiny sound that my old AVC fan would make is not there.) I'm going to try to find a pattern to avoid enlarging two adjacent holes to reduce the risk of cracking the grill. Anyway, did you just use a 1.5mm drill bit for that or what...?

 

Yes, 1.5mm is the largest diameter you can use to not overlap another hole.
I recommend to have a flat piece of wood directly under the grill and then let the drill do the job, don't push on the grill when drilling or you will create a bow in the metal and it will not look good.
To make this possible buy a high quality drill bit that is very sharp, and spray some lube on the surface and go slow and take your time.
Any thin penetrating oil will do for this job.
Bosch is probably the most high quality drill bit you can buy without going to a specialist shop, if you don't live near one I mean.
Your mileage may vary so buy more than one pack, I usually buy five or more to use for one job so I have spare ones ..these very thin drills don't last as long as larger dimensions do.

There is a cold draft under the hole that was not there before so this mod do some difference at least.
When I got the laptop I held my hand under the grill like I always do when stresstesting and it was always hot even when the fan was spinning at max rpm.
There wasn't really any suction going on even if the grill look very big because every hole is tapered, even if the slope look big the smallest dimension is almost half of the slope.
When I ran the stress tests without the panel on there was almost a 20 celsius difference and as a minimum of 10c difference in some other tests.
That would be the first thing for you to test.
Remove the bottom panel and stress test the computer, if the tests show lower temps without the panel than with the panel installed, it might be worth trying this.
Of course have the laptop elevated or turned on its side, or sitting in a docking station so the fans don't suffocate

 

Everything is measured in inches here, the closest drill bit that I can find is 1/16 in (1.588 mm), I think that it should not be too large. Pretty sure the best pattern for drilling and not enlarging two adjacent holes will enlarge 33% of the holes.
Picking up a set of Bosch drill bits and some penetrating oil this afternoon but I probably won't sit down to attempt this until the end of next week.