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HP Recommended
HP Z820
Microsoft Windows 10 (64-bit)

So here's the deal. 


I own a HP Z820, specced as follows: 


2x E5-2960 v1, 2.90ghz - 3.8ghz turbo. 

96GB DDR3 12800 RDIMM memory. 

GTX 1080. 

Current Firmware/BIOS updates. 


I love this box, but the over engineered fan header leaves something to be desired for the cooling in the environment that i am working in. I never get to 3.2ghz Turbo let alone 3.8ghz... The fans don't have enough umffff to cool the system appropriately under high loads and the chips are reaching TCASE way before they get to the theoratical 3.8ghz upper limit of the turbo of this processor.  Which is funny because ive heard the fans rev actively during boot, but they never rev that high under full operational load... Not even close. 


In short, I want to liquid cool my box, and my biggest challenge is to figure out how disable the silly fan header on the mobo so i can rip out the giant fan manifold and leave that space free for tubing and blocks.  Just for reference, HP employees, your liquid cooling solution for the Z820 is a joke... IF that 6 fan manfold is still there, i  consider it a failure...

I want two water blocks that lead to a radiator i can mount on the rear or even the top of the machine... I'm giving the BMW, a hood scoop, as it were. 


Does anyone know or is there a diagram as to how that receptacle where the fan header plugs in is wired?


What signal is required back to the mobo for it to think its there?


Can i just bridge two of the wires so it delivers a tach back to the mobo?  


Which ones do i bridge? 


I'd experiment but im pretty sure there's a good chance of shorting it out and releasing the magic smoke.... 


Im hoping with a semi quick pump and some good fluid I can keep the chips cooler better in order to prolong the amount of time they spend at turbo frequency and below their theoretical max temperature...  These chips are routinely sitting in the 70's to 80's when almost at stock frequencies at full load let alone turbo boosted....


Any assistance anyone can point out would be appreciated. 




- B 














HP Recommended

Hmm, from the z820 datasheet i've seen a z820 doesn't support an E5-2960. As such i'd assume that possibly it's a simple typo on your part and maybe you actually meant that you have an E5-2690. If so, dyslexics of the world untie :Wink:


Anyway, i'd Initially take a different tack as presumably any z820sold  with 2x E5-2690's should work as intended and spend at least  a little time in turbo boost speed of 3.8Ghz before throttling. So if it's under warranty, i'd get HP to look at it, otherwise possibly applying new and better thermal paste could help.


But if you upgraded the CPU's yourself, you may want to consider that HP workstations sold with power hungry CPU's utilize a high power heatsink/fan combo or indeed water cooling. From memory, a high power heatsink/fan combo looks like the normal assembly though it has an extra jumper wire on the connector side you plug into the mobo and it is a slightly larger heatsink with more cooling pipes. In any case, if you used a high power CPU with a normal heatsink/fan assembly, i think you get a BIOS warning during boot but not sure. Such normal & high power heatsink assembly discussions can be fount on these forums or others forum guru's may be better able to elaborate on such issues than myself.


If water cooling floats your boat, HP has already solved such issues and you can read about it here :OpenSmile:


Other than that, i can't help heuther since i don't have a z820.


[edited to add]

Maybe i'm remembering z800 heatsink/fan assemblies but searching these forums may resolve this :Surprise:

As another hint, clearing CMOS has sometimes helped in some fan speed issues so always worth a try (but do take not of any non default settings youve made).

HP Recommended

Hello, I was wondering, if you have found a way to bypass the fan sensors in the Z820.

HP Recommended

this board has a "SEARCH "function using it will let you locate all posts on the subject to are searching for such as

cooling/fans/pinouts  for the z800/820 as this has been asked numerous times


bypassing the fans on the hp workstations IS NOT RECOMENDED, hp spent a lot of time/money desiging the case cooling subsystem,.... trying to modify the cooling will usually result in the system being worse off


the z820 uses a high performance cooler when 130/150 watt cpu's are installed that has 3 heat pipes and a larger fan


the stock cooler with 2 heatpipes is only rated for 100 watts and will have problems if used on the 130/150 watt cpu's


when using 130/150 watt cpu's the power supply must be upgraded from the stock 850 watt to 1150 watts


HP makes a liquid cooling option for the cpu's  but they are somewhat hard to find and can be expensive


turbo speed on a cpu is rated two ways  single/dual cores in use max turbo speed, and more than 2 cores turbo speed


the listed cpu turbo numbers are the "fastest" the cpu "MIGHT" do. the actual speed depends on varances in the cpu chip

and the actual load on the cpu, intel does not guarante you will hit the max turbo speed


last, while it is possible to bypass the case/memory fans and make them run slower by manually installing voltage dropping resistors this method will almost allways result in the cooling being worse and cause the cpu fans to run higher


you can however from the bios, set the default system fans to run faster in several defined steps if you think you need more case cooling


last, as long as the cpu is running under the max temp intel lists for your model cpu there is nothing to fix!! it is running within spec leave it alone

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