Precision M4800 CPU upgrade, TDP concerns

Hello,

I'd like to replace my current CPU 2-core i5-4200M with a 4-core i7-4800MQ. They are compatible in terms of all parameters (socket, litography, chipset) except one: TDP. i7 has TDP of 47W, while my current i5 only 37W.

How would this 10W difference increase temperature and would the cooling system be able to handle it? Would it lead to overheating? Maximum temperature I observed so far with the i5 is 75 C.

M4800 came equipped with i7-4800MQ and even 4900MQ but I'm not sure if they had the same cooling system. It might be different depending on the CPU.

Would be grateful for any advice and suggestions whether such an upgrade would be safe.

Regards,
A.

 

The problem with the TDP is that Intel flatout lies about their TDP.

I tried the 4200M and it barely scratches 25w - 28W at maximum load, while the 4800MQ can get bottlenecked by the 47W TDP limt. So difference is in reality almost twice.

 

Pretty sure all of these systems shipped with the same heatsink, but you can check; just take the keyboard out and look to see if there are two heat pipes going from the CPU to the heat fins on the left. (Image I found somewhere) If you happen to have a single-pipe version, you'll want to source a new heatsink from eBay.

The upgrade is safe. Worst case, it gets hot under load and can't quite maintain the maximum turbo speed. The CPU will self-throttle to keep the temperature under control at a bit under 100 C. If you find it getting too hot, options to bring the temperature down are good thermal paste and undervolting.

 

Thanks for replies.
I think that after all I'll settle for i7-4712MQ with 37W TDP. It's weaker than 4800MQ (2,3-3,3GHz instead of 2,7-3,7) but at least I won't have to worry about the temperature and it's still 4-cores so I think there will be considerable performance improvement.

@Danishblunt What you're saying is also true in my case, i5-4200M never went over 30 W.

 

ignnore the 37W TDP, it's another misspec from Intel. The 4712MQ is another 50W ish CPu when turboing. The 37W refer to the stock non turbo speed, unless you plan on running it @ 2.3ghz, which will most likely make some applications worthless.

 

Cooling is not an issue if correctly matched, it depends on the cpu fan installed. (gpu and cpu heatsink is not connected on the M4800)
There are three or four unofficial fan options.

1. Sunon fan unknown cfm, only for dual core or the lowest powered quad core
2.AVC fan 4.5 cfm, there also exists a slight variation of this one too..one with a slim impeller and one 1mm thicker, I have both fans that's how I know
3.Delta fan 11.8cfm
4.AVC same model number but promises 12.5 cfm but with same 0.3 amp and same count impellers
...I'm skeptic about this one and only one vendor has it on ebay

If you ordered the M4800 with a dual core or lower tier quad core you will in the worst case scenario get the Sunon fan.
Or more generically spread out the AVC red fan.
If you ordered the computer with the highest performing cpu's you will get the Delta fan.
Now I changed my cpu fan from the AVC #2 to the Delta fan #3, not only is the fan quieter but also a lot more powerful.
The AVC fan ramped its speed to max making a horrible noise while the Delta fan roars off but still has plenty more to give if you manually control the fan speed and if you put your hand in front of the outlet grill you can already feel a hard air flow while the AVC barely tickled your face on full speed.

Now getting the part is difficult.
There are no vendors that has it in stock and bare in mind that the same D/P number is used for all these fans so you cannot ask the vendor if they can send you the Delta specific fan because they will reply that "we send whatever we have in stock matching the part number" and it will 100% be the AVC fan #2 used part.
Your only chance of getting the Delta fan is to go on ebay or aliexpress and ask if the image matches the actual part that is advertised in the ad or if its just a generic image of a matching fan.

Here is the ad for the AVC fan promising 12.5cfm
https://www.ebay.com/itm/DELL-Preci...-Big-CPU-Cooling-Fan-DC28000DDV0/272399659332

 

@unnoticed Thanks a lot for your post, that's some really valuable information you're sharing. I doubt I'd ever be able to google it
My M4800 shipped with dual core i5-4200m so it must have either the Sunon or the AVC.
I found a fan with 11.8 cfm, would that be the Delta you mentioned?
https://www.parts-people.com/index.php?action=item&id=18388

And you say you changed your fan to the Delta - what cpu have you got and did the new fan reduce the temperature?

 

You can easily check what fan you got, there are just two screws under the battery and the bottom panel will slide off.
The fans are held in with two screws each, very easy to clean while your´re in there.
Unfortunately the stickers are facing the keyboard, so unless you can identify the fan brand by the impellers you have to flip it over.
Images for reference:
Sunon has almost strait blades, fan on the left: https://tinyurl.com/y8zxvgow
AVC has slightly curved blades but spaced apart quite wide, https://tinyurl.com/y884mp4q
Delta has a wide tall cone in the middle with a swerving pattern on the impellers https://tinyurl.com/yb4eoh8j


Yes that is the one.
I have already asked parts-people about a year ago if it is the "actual" fan in the image and it is not, they replied that the image is just a stock image that applies to the D/P and they did not want to tell me or take a look at which exact fan they had in stock.
Their stock varies, often within a week it will say out of stock and stay that way for months so its not like their stock is always supplied so they might reply differently to you and bare in mind that the parts are used.
If you want you can send them an email and try ask specifically if they can confirm that they have the delta branded fan.


I am using the 4700MQ and the AVC fan struggled to keep the temperature below 88c on full load.
If I find a good deal I might swap the cpu in the future, I have already swapped all ram to 32GB.
I have SpeedStep disabled and Turbo enabled in bios to gain some performance and keep the cpu from clocking down to 0.8hz if the power supply is starting to ware out and loose connection.
With the Delta fan I can keep the temperature more steady and the fan even revs down time to time and then revs up again while doing work such as 7z compression or rendering.
The bearing is more precisely manufactured so the impeller spins more freely and is waay wayy quieter than the AVC fan. I lubed the spindle with some Muc-Off C3 Wet Ceramic Lube to give it some help.
I discovered that its not the cpu that you have to be worried about but that the power delivery easily overheat when on full load as indicated by Intel XTU software, more on this further down when I take it apart.

Temps right now from HWinfo
CPU 47c
Ambient 41c
Ambient 50c
DIMM 42c
DIMM 43c
DIMM 41c
GPU 41c
CPU 2,110 RPM
GPU 0 RPM

I have Firefox, chrome, waterfox, a virtual machine running and vlc running in the background
The fan curves are pre-programmed in the EC, whatever fan is installed it always idle at 2,110 to 2,010rpm.
Its more the duration it runs and idle.
On low loads like this or idle the cpu fan stays on for 7 minutes and stays of for around 4-5 minutes before starting to spin again.
On Windows 7 if I leave the computer it will not spin the fan at all once the cpu fan stops until some process starts, then the cpu fan starts up at around 57c.
With the Delta fan the temps are very stable and predictable.

Lately I have had issues with the computer being sluggish from time to time so yesterday I had the computer taken down to bits and solved my overheating problem that was caused by worn out thermal pads on the nvidia card memory chips and power delivery chips to the right, I put some thermal paste on them and carefully placed them on the chips and its good again.
While the nvidia gpu die had proper contact with the heatsink the other chips did not so that is why there was no temps warnings or errors leading me to the nvidia being the cause.
I tested this by first removing the card and booting the computer and the lag was gone.
I just hope it stays that way now.

To address the XTU warning while having it apart I smeared the caps left to the cpu with thermal paste and put the pads back carefully and more is better in this case.
I have done two 7zip compressions today and the fan staid on and on low so its not the cpu that overheats its the caps to the left of the cpu.
Before the cpu fan ramped up and down and up and down but now the speed is stable for a longer period of time and revving up only for a short while.

Because its the weekend I can't go out and buy parts so I had to make the best of what I already got but next time I will buy a strip of termal pad and replace all off them both on the cpu heatsink and the nvidia card.
I will probably buy the Alphacool Eisschicht thermal pad - 11W/mK 120x20x1,5mm - 2 Stück.
Don't know if 1mm or 1,5mm is best, I have to measure the pads before ordering.
Then I just measure and cut the pad to smaller pieces and make it fit..not a big deal.

Thermal paste I use is Thermal Grizzly Hydronaut 7g tube as it fullfills the ROHS because the heatsink is made of mixed metals.
I used GELID GC-EXTREME before this but I think it didn´t last as long before the temps started to rise again after it drying up and separating and its becoming very hard to get hands on this, not many stores has this in stock anymore.

Another mod I´ve made is to enlarge the holes in the bottom grill.
The largest diameter you can use is 1,5mm otherwise you will overlap the next hole and the grill will crack.
This made some difference.. the fan revs down quicker than before.
Because the fans are held in with only two screws cleaning the fans is no big deal and them getting dusty is not a problem.

Underneath the laptop I have 9mm rubber feet to give it more air underneath when the computer is sitting on a table otherwise it sits in the Dell E-Port Plus well elevated above the table.
Rubber feet can be purchased here:
https://www.ebay.com/itm/SQUARE-SELF-ADHESIVE-RUBBER-FEET-SMALL-MEDIUM-LARGE-3M/273132417432
This is probably the cheapest and easiest tech tip anyone can do to improve temps on their laptops.
There literally is no air that can pass under the laptop with the stock rubber feet so the fans suffocate leading to higher temps.

 

Thank you for your elaborate reply with loads of helpful information. I think that now I'm prepared to upgrade my laptop. Replacing thermal pads is also a good idea.
If I find the Delta fan, I'll swap the cpu to the 4800mq.

 

@unnoticed
Thanks so much for the details about the CPU fan. I had no idea that there were different types of fans with such different characteristics.

I'm constantly frustrated by the CPU fan in my M6700. It makes an annoying ramp-up noise when it ramps up from idle workload to the next highest setting (and the system likes to cycle it on and off regularly unless I keep the CPU clocked low). After seeing your post, I pulled my fan to check and it is an AVC fan. I trawled eBay and indeed for the M6700 there appear to be at least three types available: Sunon, AVC, and whatever this is.


Is this Delta? It is hard to make out the text but it does have a triangle logo. It appears to have the same type of "swerving pattern" that you mentioned for the M4800 but it is hard to tell from this angle.
(I'll probably pick it up anyway to try out; it's cheap, maybe I'll like it better...)

[Edit]
Yes I am pretty sure that says "Delta electronics" at the bottom of the circular sticker.

[Edit 2]
Ordered, it is coming from China, so I'll see it in 2-4 weeks...

[Edit 3]
Jumped on that a little too fast, it is actually a GPU fan that they had mis-labeled. Fine since I'd want to replace them both, anyway...
I've found some listings that appear to be of a Delta Electronics CPU fan (from the picture) and I'm trying to confirm with one of the sellers that it is what I think it is before I buy.