HP ProLiant Gen8 MicroServer: Lapping the CPU Heat Sink

By: John Stutsman




Figure 1 – Lapped CPU Heat Sink set to reflect the Intel Zeon E3-1265LV2 and other parts on the System Board of HP ProLiant Gen8 MicroServer


At the completion of HP ProLiant Gen8 MicroServer: Xeon E3-1265LV2 Upgrade I had completed the upgrade and successfully powered on my Gen8 MicroServer.



Figure 2 — System information showing CPU upgrade to Xeon E3-1265LV2


Afterwards I did some testing of core temperatures using iLO and Open Hardware Monitor. When heavily loaded with Prime95 I found it alarming that the core temperatures would rise steadily to about 85 degrees C in Open Hardware Monitor. The system fan speeds (the fan had been set to Optimal Cooling in BIOS) would also rise steadily from 6% to 21% where the temperature rise was arrested with iLO CPU temps of 60C.



Figure 3 — Open Hardware Monitor showing individual Core Temperatures of CPU Cores as well as other useful data.


I became concerned about the pattern of the thermal paste on the CPU (Celeron G1610T) and the CPU heat-sink when I first disassembled the MicroServer in HP ProLiant Gen8 MicroServer: Xeon E3-1265LV2 CPU Upgrade and posted my concerns in Anyone Who Has Changed the Heat Sink on a Gen8 MicroServer.

I decided to again pull the System Board Assembly and check the thermal paste and CPU heat sink. In particular I wanted to check to see if the face of the CPU Heat Sink was flat.

I used all of the procedures and steps outlined in HP ProLiant Gen8 MicroServer: Xeon E3-1265LV2 CPU Upgrade plus the additional preparations listed below to check the Heat Sink for flatness and for lapping the Heat Sink.



  1. Have handy and review Removal and Replacement Procedures beginning on page 21 of the HP ProLiant MicroServer Gen8 Maintenance and Service Guide and especially review the sections:
    • System Board Assembly on pages 28-30,
    • Heat Sink on pages 49-51, and (if you plan to replace the CPU)
    • Processor on pages 51-53
  1. Go to HP Customer Self Repair Services Media Library – Media Selection Page. Under 1. Product Category SELECT Servers. Under 2. Product Family SELECT HP ProLiant MicroServer. Under 3 Product Series SELECT HP ProLiant MicroServer Gen8. Hit RETURN to go to the Remove/Replace Videos selection menu. Watch HP’s
    • System Board Assembly Remove/Replace Video
    • Heat Sink Remove/Replace Video, and (if you plan to replace the CPU)
    • Processor Remove/Replace Video
  1. Review blog post HP ProLiant Gen8 MicroServer: Xeon E3-1265LV2 CPU Upgrade at http://homeservershow.com/
  2. For Cleaning the Heat Sink & CPU:
  1. For Checking the Heat Sink Face for Flatness
    • Metal Straight Edge (Clean the straight edge before touching the Heat Sink with it – use both sides of the straight edge to be sure the straight edge is “straight”)
    • Light Source
  1. For Lapping the Heat Sink Face
    • See/Review: How To Lap a Heat Sink at http://www.overclockersclub.com/guides/lapping/
    • See/Review “Klips” posts in thread: E5200 Lapping? Anyone Tried It? At http://www.mediasmartserver.net/forums/viewtopic.php?t=7531
    • 12” x 10” piece of glass (available at Menards) and painters tape to attach sandpaper to glass
    • Liquid soap (borrowed from kitchen)
    • Sandpaper, wet/dry type, starting at 400 grit, 800, 1000, 1500, & 2000. If you want you could add 600, 1200, & 2500 to that mix. Start with 400 and when Face is Flat THEN work your way up to achieve a mirror finish.
  1. For Cleaning & Installing the Heat Sink & CPU:



Figure 4 — Cables disconnected from System Board Assembly before removal


In this Video (Video 1: HP ProLiant Gen8 MicroServer System Board Assembly Removal) I remove the System Board Assembly:



Figure 5 — Preparing to Remove the Heat Sink from the CPU (Xeon E3-1265LV2)


In this Video (Video 2: CPU Heat Sink Removal: HP ProLiant Gen8 MicroServer) I removed the CPU Heat Sink:



Figure 6 — Preparing to Clean the Heat Sink & CPU then test the Face of the Heat Sink for Flatness


In this Video (Video 3: Clean Heat Sink & CPU: HP ProLiant Gen8 MicroServer) I clean thermal material off of the Heat Sink & CPU, then I confirmed that the face of the CPU Heat Sink was not flat:



Figure 7 — By lifting the Heat Sink up and looking along the face of the Heat Sink with the metal Straight Edge across the Heat Sink and the overhead lights behind the Straight Edge and Heat Sink I confirmed that the Heat Sink face was NOT flat.  See Figure 8 & Video 3.



Figure 8 — By lifting the Heat Sink up and looking along the face of the Heat Sink with the metal Straight Edge across the Heat Sink and the overhead lights behind the Straight Edge and Heat Sink I confirmed that the Heat Sink face was NOT flat.  See Figure 7 & Video 3.



Figure 9 — Preparing to Lap the Heat Sink using wet/dry sandpaper



Figure 10 — 12″ X 10″ piece of glass to be used as base for the Sandpaper during lapping



Figure 11 — Mirror finish on Heat Sink after Lapping


Update 2/13/2014

Al_Borges, a member of our HSS forums, who I had the good fortune to meet at the #BestEverMeetup #2013MeetUp shared with me some of his knowledge as a Metallurgist in the Aluminum Industry about lapping AL – which he does regularly to view AL samples metallographically.

“Your basic technique was fine –  however,  you would have had much better and faster results if you had started with 80 or 120 grit –  followed up with 220 then lastly  400.   Lubricating it with water will also help.

The aluminum oxide you are sanding off is as hard as the grit.  Sanding with too fine a grit will let the particles ball up between the work piece and the tool and you won’t get any metal removal. The coarser grits will cut into the surface.”

Many Thanks to Al_Borges and I hope this information will help others in the future should they find the need to lap their Heat Sink to get a flat surface on it.

So bottom line, If I was to do it over again, I would start with the 80 or 120 grit wet/dry sandpaper and after getting the heat sink face flat I would move up to the 220 then the 400 then I could have stopped.


In this Video (Video 4: Lapping the Heat Sink: HP ProLiant Gen8 MicroServer) I will begin Lapping the CPU Heat Sink:



Figure 12 — Preparing to install the Lapped Heat Sink



Figure 13 — Arctic Silver 5 applied to Xeon E3-1265LV2 and Heat Sink face reflecting System Board components



Figure 14 — Another view of System Board and CPU with Thermal material applied


In this Video (Video 5: Install Heat Sink: HP ProLiant Gen8 MicroServer) I INTSALL my Lapped CPU Heat Sink:



Figure 15 — Preparing to install the System Board Assembly & Power-Up


In this Video (Video 6: Install System Board Assembly: HP ProLiant Gen8 MicroServer) I Install my System Board Assembly & Power-Up my Gen8 MicroServer:



Figure 16 — 7 Day (168 hours) break-in run with Fans set in BIOS to “Increased Cooling” resulting in fan speeds from 36% to 41% during that period.


Additional testing of temperatures under heavy load will be discussed in a subsequent report.



I removed and tested the CPU Heat Sink from my Gen8 MicroServer and found that it was not flat. I then lapped the Heat Sink until it was flat and reassembled my Gen8 MicroServer. I’ve allowed it run at different power levels during the 200 hour break-in period for Arctic Silver 5, after which, I will do some additional temperature testing and response to heavy loads.


My system configuration As-Built:

  • HP ProLiant Gen8 MicroServer Xeon E3-1265LV2
  • 16GB RAM – Kingston KVR1333D3E9SK2/16G (this RAM had previously been in my N40L MicroServer)
  • OS Drive: HP Dynamic Smart Array B120i RAID Controller – Logical RAID0 Drive made with two (2) physical drives VelociRaptor WD1500HLHX (the physical drives were attached to SATAIII [6Gbps] Ports 0 & 1 and are SGDM mounted)
  • OS: Windows Server 2012 Standard
  • iLO 4 Advanced



Figure 17 — As-Built: HP ProLiant Gen8 MicroServer Xeon E3-1265LV2



If you want to learn more about the Gen8 MicroServer a good place to start is ProLiant MicroServer Gen8 Links and the MicroServer Forum and MicroServer Gen8 Sub-Forum of the HSS Forums where you are welcomed to join us with any questions and/or comments on the above and other threads. Be sure to check out the References at the end of this post.



Xeon E3-1265LV2 Upgrade in HP ProLiant Gen8 MicroServer

MicroServer Gen8 Sub-Forum

Anyone Who Has Changed the Heat Sink on a Gen8 MicroServer

ProLiant MicroServer Gen8 Links

The Schoondoggy Gen8 Drive Mount for the HP ProLiant Gen8 MicroServer First Look

Useful MicroServer Links & References

MicroServer Hardware Links

MicroServer Forum

MicroServer Blog Postings


References I referred to about thermal compound use

Arctic Silver Thermal Compound Application Method – Vertical Line

Puget Systems Thermal Paste Application Techniques

Updating a Gigabyte X58A-UD3H and Unboxing a Zalman CNPS9900 MAX (Blue) CPU Cooler

Repurposing an Acer Aspire Revo AR3610-U9022 Net-Top with a SSD and Windows 8

Updating a Gigabyte Z77X-UD5H and i7-3770 in a PC-KW9X with a Zalman CPU Cooler


You may also like...

1 Response

  1. mclmm says:

    Excellent post!

    I'm very curious about the net results of the project, when will the follow-up post be completed?

    Keep up the great work!