XPS 15 9550 temperature observations (undervolt + repaste)

I had a couple of hours to mess around with the XPS 15 9550 in my sig (i5 version) and decided to see what temperatures I was hitting. I tested it under Prime95 small fft's for 20 minutes and looked at the average temperature. I tested it first with all stock settings/paste and then undervolted by 185mv (a setting that is prime stable for me). After that I repasted the cpu and gpu with IC Diamond thermal paste, tried it at stock voltage, and then undervolted again.

Here are the results

Stock - 73*C
Undervolt by 185mv - 59*C
Stock voltage with repaste - 68*C
Repaste and undervolt by 185mv - 53*C

One good thing with the undervolt is the fans were also able to run at a step slower - reducing noise output by a fair amount. The undervolt and repaste again allowed the fans to step down again, producing the best results.

Another thing I looked at was my 950pro SSD. My laptop came with the 32gb cache drive, so it did not have the thermal pad. Using AIDA64 I was idling at 40*C and hitting 63*C in ATTO. I put some 2mm thermal pad between the SSD and the bottom case and now it idles at 29*C and hit 39*C in ATTO. A fairly good reduction I'd say.

Figured I'd throw up some results for you guys. I wanted to get some GPU temps (before and after repaste), but I didn't have enough time.

*ON EDIT*
There has been some discussion on trying to cool down the VRM area (~page 50) which seems to be causing throttling for a few members. I have had good experience cooling the R22 chokes seen on page 27 with cheap 1mm thermal pads, however Pressing had a negative one using high thermal conductivity pads on his. YMMV.

Secondvision has put together a great summary with a table of results


So I have had a couple of people ask me to do a repasting how-to so here is a brief one:

1. Get your laptop and tools ready. You will need a phillips screwdriver, T5 driver, something to clean the old thermal paste off (I like arctic clean), new thermal paste (recently tried and absolutely love kryonaut thermal grizzly).


2. Remove the back cover of your XPS 9550.


3. Unplug the battery cable (carefully).


4. Remove the heatsink. See how wonderful of a job dell does at pasting...


5. Remove old paste making sure to clean it well and not get it on anything else.


6. Apply a small line of paste to the cpu and gpu. Note that this application doesn't look very good and it may be difficult to see how much I applied. It's always a good idea to do a trial fit where you apply it and seat the heatsink and then take it off to see how well the application went (you have to clean it and reapply after that though). You can also see that I changed the thermal pad under the heat pipe to one that is around 1.5mm thick because the stock pad did not come near touching the ram chip.


7. Reinstall the heatsink, plug in the battery cable, put the back of the case on...

 

Thanks for this. Would be curious as to how much undervolting extends battery runtime.

What tool did you use to do the actual undervolting?

Also, what was thermal brand/rating of thermal pad?

 

Did the CPU stayed at 2.8 GHz?

Please run Furmark on your machine and post results. Mine stays at around 70C with 1.1GHZ 950MHz core clock. If I run Furmark and primes together I get gpu at 80C @ 1.1GHz, CPU around 70C @2.2GHz.The heatsinks above VRAM are not perfectly flat and cause the GPU plate to make poor contact with GPU. CPU is fine.

Did you remove the sticker from 950Pro? Or did you place the pad on it?

 

I used intel XTU to do the undervolting and temperature monitoring. For the thermal pad, sadly it's just some cheap one with a thermal conductivity of 3.2w/m-K. My good Fujipoly is only .5mm thick... No ideas on how much battery life the undervolting will save, but the fans not running as much will also help a little.

I'll run some Furmark tonight to see what I get. I did not remove the sticker from the 950 pro, I left it on there.

 

Well your temps are certainly better than mine in the GPU. My GPU hits 80*C running just Furmark and then 90*C with prime thrown in the mix. I don't know if I have a bad GPU repaste or what.

 

Can Intel xtu auto undervolt on cold boot? Under volt sounds cool and useful. A must, but it needs to set n forget preferably

 

What about throttling? It should throttle down, the temps I posted were below stock speeds. And what about fan speeds - are they going full throttle? I forgot I had it once on 'quiet' settings and the fans didn;t ramp up causing high temps. I took it apart again, did repaste and some bending of the heatpipe, put some aluminium foil to cover gaps, and right now I when running primes and furmark together I have stable 72C @ 850MHz on GPU and 69C @ 2.2 GHz on CPU.

Have a look at the VRAM modules just next to the gpu fan. Remove the fan to have a better view. I bet that you will see same thing as mine did: a corner of the plate rests on the chip, angled, the other chip has no contact at all with the plate, and the plate is lifted from the GPU.

 

I have XTU autolaunching on startup. I don't know if this is required, but it automatically loads my undervolt profile each time windows starts.

I didn't notice is throttling, but I thought 1.1ghz was stock speed? I will check out the contact between the GPU and the heatsink and see if mine has the same problem.

 

Sorry, it was 70C @ 950MHz, I edited the other post. I'm running it again and after 15 minutes I get 77C @ 1.1GHz with Furmark only.

 

That's pretty good performance I think. Did you change the thermal pad for the VRAMs? If so, what is the thickness of your new pads? Thanks.

 

Here were my observations with HWMonitor and IBT w/ 10 passes.

Normal Voltage
66/69/66/68/68

Undervolt -100mv
61/63/60/62/63

Undervolt -150mv
59/61/59/60/61

Numbers read as Core 1/2/3/4 and Package.

Not a long benchmark (around 2 minutes), but it gives a general sense of how undervolting the Skylake affects the temperatures.

Never really bothered checking until this thread came up because my temperatures were always fairly low even during gaming.

Will run these three tests again followed by a GC-Extreme repaste.

 

Custom,

Interesting post! I used XTU to undervolt and noticed very similar results as yours (without the re-paste). I used XTU's stress test for 20 minutes, with regular voltage was hovering around 60-62C Core Temp, undervolted -184mV and noticed core temps were down about 10C. Fans also spin a lot less.

Will this cause any sort of performance drop? I like a quieter and cooler machine for sure. Most use cases for me don't need raw horsepower - although I do use my XPS15 i5 to play some games. Will be interesting to see if fans are any quieter with an undervolted CPU during gameplay. I imagine not; GPU likely drives the thermal profile too much.

How do you run XTU at startup (manually put in startup folder?) and how do you get it to load a voltage profile by default? It seems pretty manual to me (you have to click a profile, "show values" and then click Apply).

 

Also, what's the conclusion - is the repaste really worth it? I'd rather not mess with internals too much at this point, but the XPS15 seems pretty serviceable.

 

Ok, sounds great, i am going to try XTU this weekend and report back!
My PC i overclock with lower voltage and C-states, so i am very interested to see it work out on a laptop.

 

It won't drop performance any. So long as the system is stable at the lower voltage you are good to go. It may not lower fan speeds while gaming, but I'm sure it does help lower the load on the cooling system.

I just manually copied XTU to the startup folder exactly like you thought. All you have to do is create, save, and apply a profile and it will load that one everytime you run XTU (unless the system crashes, then it reverts back to default).

As far as the repaste being worth it or not, it really depends. For me it is worth the 5* drop, but I haven't owned a computer that I haven't repasted before... If you're not as comfortable with doing it yourself or are considering returning the laptop, I would skip the repaste. The undervolt on it's own offers a huge decrease in temps.

 

Oh ok, I didn't know XTU would apply the last used profile upon startup. Should be easy enough to add to startup.

As someone who used to build PC's for a startup - I'm completely comfortable with all things computer, I'm just lazy and don't want to crack open the case again. If it really helps with GPU cooling and keeps the fans at a lower RPM, I might completely go for that. I observe that fans reach near 100% when GTX960 GPU goes above 89-90C - so if thermal paste keeps them just below that, it might make the machine even more enjoyable during gaming sessions, especially in a quieter bedroom while my wife is asleep!

 

Ok i just tried undervolt with XTU and on auto startup, seems very clean and un-intrusive. I like.

Tested on battery, with R15 cinebench, undervolt -185mv. I get 585 points.

Seems stable with R15 and XTU stress test of a few 5 mins run.

My vcore readings via HWInfo are min 0.6v, max 0.8v. Am i getting the same vcore readings as you guys?

 

Are you guys sure you need to explicitly start XTU? I thought it has a service running that applies all the settings on startup. I know I don't have it added to startup and when I crashed my PC ones after reboot I was greeted with XTU GUI saying that since my machine died all settings are back to stock.

 

Yeah I wasn't sure if it needed to start up automatically or not, sounds like the service takes care of everything...

 

So thanks to Thysanoptera's suggestion, I decided to take a look at the heatsink. The results, it's bent from the factory (yay).

Here are some pictures.

I took the thermal pad off of the GPU ram to better illustrate this point:

Hard to tell, but you can see where there is a large gap between one memory chip and almost no gap for the second. The memory chip on the left had zero contact with the heatsink/heat pipes at all...

Here you can see how bent the heatsink is compared to my calipers:

Again a little tough to see, but toward the left you can see a gap as the heatsink bends away from the calipers.

Last thing I noticed is that the thermal pad is likely too thick. All of the memory chips except the one that has to contact the heat pipes are very close. I was able to use .5mm thermal pad between the modules and it made great contact. I also used 1mm thermal pad over the heatpipes so that the loner memory chip actually makes contact.



So after carefully bending the heatsink (be amazingly careful as it's super easy to bend/pinch off a heatpipe), I was able to better contact the gpu and it's memory chips. Furmark only shows a 3*C drop in temps, but I'm happy knowing my loner memory chip is actually making contact with the heatsink.

 

Hi,
my respect to your enhancements. But doesn't this void your warranty?
Best regards,
Gerhard

 

The heatsink is a replaceable part. I don't have a good answer for that question though. I wouldn't recommend doing it if you're concerned about the warranty, it was more of a FYI deal for me.

 

Hmm...i make a shut and cold boot, the XTU is not loaded..
How to ensure XTU profile is always loaded whether reboot or cold boot? I love the undervolting! I need it!

 

Once XTU settings are applied, they are set to automatically reapply on startup unless your computer crashes (for whatever reasons).

 

My observation is XTU settings would apply on first reboot/restart, but next restart it goes back to default.
Any help how to make it stick? I make wrong settings somewhere?

 

Mine looked exactly the same, so most likely everybody has one memory chip isolated from the heatsink. I wonder what the failure rate of it will be in the future.

 

Probably the same person responsible from mishandling during assembly, I will be taking mine off to repaste when I swap the SSD so I will report back.

 

Forgive my ignorance! I now noticed XTU do apply on a reboot, it just takes about 2 mins later to load up! What a delay start.

Stress testing with this x264 app for 5 loops at 8 threads http://www.overclock.net/t/1411077/haswell-overclocking-guide-with-statistics

Max temps is +30 Celsius over ambient
Max Hwinfo vid is 0.9v
Min Hwinfo vid is 0.6v
-185mv offset.
Seems a good one.

Everyone should join in the XTU bandwagon imo.
Really nice invisible app. It even allows overclock of iGPU, but i didnt try it.

 

Im getting really high temps on my i7 6700. We're talking over 90C when running some gpu+cpu intensive benchmarks. Under full load ]with CPU only behncmarks, I'm hitting low 80s. Should I try to reseat the heat spreader, maybe apply new thermal grease. Or should I look into getting it repaired. Or is this normal?

 

Looks normal to me. Keep in mind that at least me and OP have i5 so our temps will be lower. I just checked again and I'm getting some 69C running primes with fans at 4k rpm at stock voltage and CPU locked at 2.8 GHz. So i7 (higher clock + HT) in low 80s seems reasonable.

 

You guys can do -185mV on the i5? That's impressive. Mine (in the XPS 13) gets unstable around -95mV, so I run it at -80mV. Still a few degrees cooler, but damn.

 

i7-6700HQ here as well. Temp around 81C running Prime95 alone to stress CPU. This is without installing XTU or any repasting.

 

Is there a software tool to monitor fan speed of the 9550? Fans don't show up with any tools I have. It would be good to monitor/report temps under load and corresponding RPM for the 2 fans.

 

Hi guys,
can I ask you for a favor? I am thinking about this great laptop and since this is thread about temps, could someone do a gaming test for me?
I am occasional player, I like to play some games from time to time (now aimimng for Witcher 3, Fallout 3, Tomb Raider 2013, Far cry4 etc) and I wonder how the temperatures are handled during like 2-3 hours of continuous heavy gaming. This laptop looks like a perfect compromise between size, weight and power for everything (even though not the cheapest one), it's on top of my list now (for curious ones, there is also MSI GS40 and Inspiron 15 7559)...

 

Ya my is i7 running between 0.6v. to 0.9v using Intel xtu. What is your XPS13 voltage range? It may be too low already to get -185 mv

 

I also run my XPS 13 i5 6200u at -85mV and the GPU at -50mV. Anything lower and I get random BSOD's sometimes. I guess the i5 6200U has a tighter voltage by default.

The fans in my XPS 13 rarely even spin up unless I'm playing something like CSGO and the battery life seems to have improved a little bit too.

 

Others could answer this better as I've only done stress tests on mine (Prime95 and Unigine Valley, but not at same time).

CPU/GPU temps will be high (but don't seem to throttle), as laptop is designed to run that way to minimize fan speed/quietness - which it does well.

Underside base of laptop gets warm, but not hot - I can leave it on my lap when doing stress tests. (Note there's two fan intake ports on underside that are right about where your legs are - must be careful not to block them completely.)

Upper keys near exhaust port slot (function keys) get warm, although not uncomfortably so for me. See Notebookcheck's reviews for actual temps.

Be aware, though, that response times of the screen aren't that great and ghosting occurs, which you may or may not notice/care about for gaming. For FHD panel, black to white times are 13 ms rise and 27 ms fall. 50% grey to 80% grey times are 25ms rise, 37 ms fall. See Notebookcheck's FHD review for details. Notebookcheck's UHD review has times for 4k panel, which are about the same. These times seem to match the panel's specs, so I don't think it's a defect. That said, I have the FHD and the screen is gorgeous.

 

Hwinfo64 shows both fans speed.

 

aida64 should

 

I've gotten down to a -155mv undervolt so far on my i7 with no stability issues whatsoever. Went from hitting the mid 90s, fans running full speed, and some minor throttling when letting prime95 run for a long time to staying in the low 80s with the fans only hitting max speed for a few seconds once or twice (the fans slowed down to nearly inaudible levels a few times while running prime 95!) and no throttling. Gonna seehow far I can go with the undervolting. Hopefully I can hit 185 like some of the i5 users.

I feel like I got lucky and unlucky with this laptop. My processor definitely has some solid undervolting potential which I am very happy about. But there is clearly something wrong with my cooling system since I am easily able to hit mid 90s and incur throttling on the both the cpu and gpu (with stock voltages). It seems this isn't typical as most reviewers said there werent any hints of throttling, and most users are maxing out in the low 80s in stead of 90s. I think Im gonna open up the laptop and see what the situation looks like. Considering trying repasting or at least repositioning the cooler to see if I can improve things. If I can get stock voltages to give temps close to what other people with i7s are seeing, I think i'll be in an awesome situation with the undervolting.

edit: fixed some numbers regarding temps and voltages.

 

That makes sense, thanks. Mine runs between .55 and .89, so it has lower voltages configured to begin with, as @ pauldegroot suggested, too.

 

Ok, here are my findings with the i5-6300HQ after 10 minutes of small FFTs.

With an undervolt of 150mv, max it ever hit was 61 degrees across all cores.

With an undervolt of 150mv and a repaste of Gelid GC-Extreme, max it ever hit was 57 across all cores.

I didn't run a stock test, but I'd imagine it'd be around 68-70 like my last test.

 

Thanks. For me, I didn't realize it wasn't showing up until under load.

 

Where do you guys see the fans in HWInfo, I can't ever find the RPM count.

Does anyone else notice "odd" fan performance at times? I can't find a relationship on the lower end and fan noise. CPU temps will be at or less than 38C but fans will kick up? Maybe there's a system chip elsewhere that's warming up, I just can't find the reason why, at times I'll get significant fan noise for no reason. Also, there might be a relationship between charging on AC and fans?

 

It only shows up for me if I'm running Prime95 or something. It's at the bottom of my "Sensors Only" display. First image with fans, second thumbnail without.

Yes on the odd fan performance. Mine right now once kicked in doesn't slow down, even once temps go way down.

 

One side question, i´d like to change the screws of the XPS15 when doing the repaste, does anyone knoq the exact measures of them, that i might find replacements? However the screws arent of very strong metal so they are easily ruined after opening the case a couple of times, thats why i´d like to get some extra screws...

Any experience on that?

 

That's a good question, I don't know who would stock such a small screw size besides maybe an RC hobby shop or something similar. I don't have any thread gauges that small either. Hopefully someone else here has a better idea. Perhaps chatting with dell tech support would help?

 

Nothing wrong with these screws so long as you use a good screwdriver and not some £0.99p special. Personally I only use "Wera TX 5 HF" & have never stripped one yet

 

Yes they are not generally worse than any other laptop screws, however using a bad quality torx easily ruins them ;-). As far as i know it was T5 m2x3 for the 9530 does anyone know if the screws are the same for the 9550?

 

yeah the clues in my above post