[UPDATED]: Thermal paste for Xeon Skylake CPUs

[hmw]

Upgrading from Xeon Silver 4114s to Xeon Gold 6138's. The Gold's do run hotter than the Silvers - usually I would use Noctua NT-H1 or NT-H2 as the thermal paste since it's a LOT more affordable when swapping out 8-10 large processors.

But decided to ask around in the forums if anyone has had any bad experiences with Noctua especially with what folks refer to as 'pump out' i.e. the paste seems to get pumped out when the CPUs run at higher temps.

Or conversely - what paste have you used and found stable long term (Artic Silver 5? Arctic Cooling MX5?)

TBH I think Dell lathers on some really cheap paste that they buy in bulk tubs

Update: ended up using TPCM (Thermal Phase Change Material) - so far so good. I've posted more details in the thread ...

 

[drdepasquale]

Upgrading from Xeon Silver 4114s to Xeon Gold 6138's. The Gold's do run hotter than the Silvers - usually I would use Noctua NT-H1 or NT-H2 as the thermal paste since it's a LOT more affordable when swapping out 8-10 large processors.

But decided to ask around in the forums if anyone has had any bad experiences with Noctua especially with what folks refer to as 'pump out' i.e. the paste seems to get pumped out when the CPUs run at higher temps.

Or conversely - what paste have you used and found stable long term (Artic Silver 5? Arctic Cooling MX5?)

TBH I think Dell lathers on some really cheap paste that they buy in bulk tubs

Artic Silver 5 works well for large CPUs

 

[RolloZ170]

Or conversely - what paste have you used and found stable long term (Artic Silver 5? Arctic Cooling MX5?)

MX5 had issues and is not produced anymore, the successor is MX6.
why should 6138 run hot ? what coolers do you use ?

 

[Wasmachineman_NL]

AS5 is positively ancient these days, I personally swear by GC-Extreme. (my P50 has been repasted in 2019 and it's still holding up fine!)

 

[hmw]

MX5 had issues and is not produced anymore, the successor is MX6.
why should 6138 run hot ? what coolers do you use ?

Just read about MX5 - thanks for the heads up !

I am currently running the lower power Xeon 4114's in Dell R440s and they run hot even at idle ( 70c ~ 74c ). I did find this article from Dell: Customer concern--Does running the CPU at high temperatures for extended periods of time impact its quality and lifespan？ | Dell US

 

[hmw]

AS5 is positively ancient these days, I personally swear by GC-Extreme. (my P50 has been repasted in 2019 and it's still holding up fine!)

How's the viscosity? I was reading that the more viscous pastes don't suffer from pump-out or problems with efficacy sharply decreasing over time (aka Kryonaut).

Actually found the following viscosity and density for Kold-01, GC-Extreme and MX6 if anyone is interested

	Viscosity (pa S)	Density (g/cm3)	Price
Gelid GC-Extreme	85	3.73	$24 / 10g
MX6	45	2.6	$11 / 8g
Kold-01	100	2.6	$14 / 5g

 

[Wasmachineman_NL]

How's the viscosity? I was reading that the more viscous pastes don't suffer from pump-out or problems with efficacy sharply decreasing over time (aka Kryonaut).

Actually found the following viscosity and density for Kold-01, GC-Extreme and MX6 if anyone is interested

	Viscosity (pa S)	Density (g/cm3)	Price
Gelid GC-Extreme	85	3.73	$24 / 10g
MX6	45	2.6	$11 / 8g
Kold-01	100	2.6	$14 / 5g

GC-Extreme is not too viscous, but it resists pumpout very well.

 

[hmw]

Ended up using TPCM - thermal phase change material. These are materials that soften from 50c ~ 70c and 'flow' more easily, filling in all the microscopic cracks just like thermal grease. The advantage is that they can be applied as a pad i.e. with uniform thickness

Most folks use Honeywell TPCM 7950 (PTM7000 Series | Honeywell) which has a thermal conductivity of 6.0 ~ 8.5 W/m-K. The usual route to buy is to order via AliExpress. I didnt want to risk getting something unknown from China so looked around for an alternative and found this: https://www.laird.com/products/thermal-interface-materials/phase-change/tpcm-7000

It's from Laird (owned by DuPont) and has a thermal conductivity of 7.5 W/m-K. Unlike the Honeywell SKU, this one comes in a range of thickness, but I chose the same 0.25mm thickness that the Honeywell has. It's SKU #A18172-10 (TPCM 7250 9" x 9" sheet).



DigiKey and Mouser stock these for a grand total of $33 for a 9" x 9" sheet. I used a 2" x 1.75" pad on top of each Xeon



Before, the 85W Xeon Silvers were doing 70c ~ 71c idle. Right now with 140W Xeon Gold 6138s, here's my idle temps



Or maybe the Xeon Gold's are more efficient. Who knows

 

[Whaaat]

Or maybe the Xeon Gold's are more efficient. Who knows

Can you please report the idle power consumption of the system or processors as well?

 

[hmw]

Can you please report the idle power consumption of the system or processors as well?

I get anywhere from 190w ~ 208w idle. This is with 2 Xeon Gold 6138, 128GB DDR4-2666, 3 x SATA SSDs + 1 x SAS SSD, 1 x XL710 NIC. Previously with the same config and Xeon Silver 4114s, the idle was 140w ~ 155w.

Of course if you are running Linux or Windows, the idle power will be MUCH lower. But when running ESXi, the system doesn't idle in a low power state as much - this is by design

UPDATE: With Linux, the idle temps are 50/54c and idle power is 178W

 

[Micro]

just for comparison - my workstation uses 2 Xeon Platinum 8260L, 48gb DDR4-2933, on an Asus WS-621e-Sage mb.
As I type (and also downloading from YouTube, so essentially idle) Core temp is showing the hottest core of each CPU to be 57c, with power consumption as 11.3w on cpu0 and 10.4w on cpu1 (tdp is 165w)
I use Thermal Grizzly Hydronaut Thermal paste (it's non-conductive, cause I'm not always the best at applying ) along with Dynatron B-series air coolers

 

[radi4fun]

We use Shin-Etsu G751 1.5G syringes and and it keeps the temps of our 8280L's at idle in the mid 40's. This is on SR950 with 8x 8280L and 48x128GB DIMMS and few other things. The power usage.....

 

[sam55todd]

I'm using MX4 on most older systems (CPU, VRM, PCH, GPU, NVMe and some other hot components) and MX6 recently,
thermal conductivity is primary selection criteria, then non-toxicity and non-electrical-conductivity as mandatory part, and finally viscosity (plus durability over time, some old compounds become useless after 1-2 years, although I'm not keeping PCs for any longer than that anyways)

Based on publicly available specifications I wouldn't go with anything below 8 w/m K (especially for CPU)
Thermal Grizzly Hydronaut (TG-H-030-R) : 11.8 w/m K
Cooler Master MasterGel Pro V2: 9 w/m K
Artic Silver 5 : 8.9 w/m K
Arctic MX6 : 7.5 w/m K (some report 10.5)
Arctic MX5 : 9.8 w/m K
Arctic MX4 : 8.5 w/m K
Gelid GC-Extreme: 8.5 w/m K
Honeywell TPCM 7950: 7.5 w/m K
Tpcm™ 7000 : 7.5 w/m K
Shin-Etsu G751: 4.5 w/m K
Kold-01 - dodgy specs not following standards, most likely intentionally to mislead, won't even consider.

 

[gb00s]

All servers home/company running with Kryosheets instead of thermal paste. No significant temp diffs observed. It was just 1-2C here. But it was a one time investment, no dirty fingers, no shortage of thermal paste when u need it and no maintenance. When server need to run they can run w/o interruption. If you test things out, you just use the sheets. No paste hassle. In this environment, never ever will I use smthg else.