HP Z840 CPU Cooler clarification

[mc1903]

I am running a pair of Z840’s with E5-2690 v3 CPU’s and the ‘standard’ coolers as my VMware home lab.

I recently upgraded both to have 512 GB using 16 x 32GB 2400 DIMMS each and this has moved my previous memory ‘bottle neck’ to a CPU one now 😕

So I am considering upgrading the CPU’s to either E5-2699 v4, E5-2699A v4 or poss E5-4669 v4 (I saw another post on here saying the E5-46xx v4 work in a Z840 OK).

My question is do I need to change my standard CPU coolers out for the fancy “Z Cooler” type or will the standard ones cool 145 TDP CPU’s OK? I fully expect the fans to run a faster/louder, but I could live with that.

I cannot see any guidance in the Z840 QuickSpecs for any mandatory Z Cooler usage with any specific CPU models.

Any advice will be welcomed.

Cheers

M

[DGroves]

 HP never offered the system with the 140 watt cpu's as such it's best practice to follow the z820 guidelines which uses the same cooling system  and use  the older optional water cooling kit or the  current "vapor" coolers with 140/150 watt cpu's note that per HP these also require the optional 1125 watt power supply

if you use the stock coolers with a 140 watt cpu(s) you will need to increase the default case fan speed and indeed live with increased cpu cooler fan speeds,  just how much.... will depend on your room temp the z840 sits in and what load the cpu's run at and for how long they run at peak loads 

[mc1903]

Thank you @DGroves.

I cannot see any Z Coolers available online. I have found some of the 635869-002 Z820 water cooling kits on eBay (£159 each 😭), but they look to have a 4-pin PWM style fan header connection. Looking at my Z840 system board the CPUx auxiliary cooler headers are only 3 pin.

Do you happen to know any detail on the Z820 water cooling kit pin out? | assume it is some kind of pump, but I might be able to find a 3rd party controller to attach it to.

My only luck in all of this, so far, is that I do have the 1125 watt PSU's... #smallwin.

Cheers,

M

[DGroves]

the z820/840 cooling systems are identical, both motherboards use the fans in the main black cooling shroud for the stock cpu coolers and will use the optional 3pin watercooling headers located on the motherboards which are for the HP water cooling kits pump, the cpu is still cooled using the fans in the large black cooling shroud , same for the vapor coolers however they don't need the 3 pin header for power

https://www.youtube.com/watch?v=q3YFqH5pdDA

[mc1903]

Thanks again for your help @DGroves.

I am not convinced about the Z820 liquid coolers; the ones I have found a video on have 4 pins. Screen grab from Youtube - https://youtu.be/LZ8TGjtxEo0?t=459

Whilst I look for Z Coolers appearing online, I will use the stock coolers and ramp up the fan speed in the BIOS.

As there is no IPMI on the Z840's, I am not sure how to monitor CPU temps. Nothing is passed through to the ESXi OS in way of sensors; so I think a 3rd party temperature monitor with some insulated thermocouples might be an option.

[DGroves]

the Z840 Vapor cooler has two bonded ground wires attached to the base of each cooler that then feeds out to a white 4-pin plug end, which attaches to a 4-pin header on the z820/Z840 motherboard... one header for each Vapor cooler.  Those headers are noted in the Z840 manual.  and only pin 1 and pin 3 are used at each header which are for ground continuity to let the Z840 motherboard bios know that the vapor cooler is installed

both the z820 and the z840 motherboards have 4 pin headers  for the upgraded cooling however the z820 pump only uses 3 of the 4 pins

for high power z820 cpu's the plug must be connected to prevent 528: CPU requires liquid cooling system error

https://faqs.noctua.at/en/support/solutions/articles/101000081757-what-pin-configuration-do-noctua-f...

hp workstations usually follow the standard wiring sequence for fans unlike Dell!

 hp water cooling :  635869-002

https://www.ebay.com/itm/165804282362?hash=item269ab491fa:g:6tcAAOSwhBJkidpQ

[mc1903]

Hi,

I just opened up one of my Z840's and it does not have 4 pin headers for the CPUx Aux cooler connections - they are both 3 pin.

HP Z840 'CPU0 AUX COOLER' 3 Pin Header

HP Z840 'CPU1 AUX COOLER' 3 Pin Header

HP Z840 Workstation system board components

 

Are you saying the 4 pin connector on the Z820 liquid coolers will fit/work on these Z840 3 pin headers? Have you done this exact setup yourself previously and have you seen it work?

I am happy that the Z cooler / vapor cooler is a 3 pin connection. Screen grab from Youtube - https://youtu.be/QzEuIzUmgRs?t=1395

I am really appreciative of your help and I do not mean to be argumentative, but I am spending hard earned cash here; so I need to be 100% sure... 

Cheers

M

 

[DGroves]

the z820 motherboard has a 4 pin water cooling aux header, but the HP water cooling kit pump 4 pin connector only uses 3 of the 4 pins (one end pin is unused)

the z840 only has a 3 pin aux connector for the 3d vapor cooling option as there was no water cooling option and the vapor cooler itself had a 4 pin connector on some of the coolers (with only 3 of the 4 connectors used) later ones now only use a 3 pin connector (with the center pin unused) the used pins are 1 and 3  (Ground and Sense which are shorted together)

on the z840 the 2 pins when used, just tell the bios to use a different fan cooling profile, the system is still cooled via the main cooling shroud

on the z820 the MB AUX header pins provide only power/rpm sense  for the AIO pump, and the Bios also detects the AIO pump rpm from the MB Aux sense wire and loads a different CPU cooling profile some people just don't connect the vapor coolers plug to the z820 MB, i  personally would  get 2 small 3 pin 12v dc fans and connect them to the z820 AIO headers if the fans are small, you can mount them just about anywhere, and they will trick the z820 bios into thinking the AIO pump is connected

the z840 vapor cooler plug is compatible with the z820

look at this link for the z820 water AIO plug wiring

https://www.amazon.com/G0J48AA-Liquid-Cooling-Heatsink-Module/dp/B00K4RSUM4

now the z840 vapor cooler

https://www.amazon.com/RKEBK-781908-001-828231-001-N3R54AA-Heatsink/dp/B0CNJQRZ5T

[mc1903]

Thanks again.

Is there any indication given in the Z840 BIOS that it is using a different profile, when the CPUx AUX pins 1 & 3 are shorted? Also, just checking that this a 'zero ohm' dead short and that I don't need any set resistance between the pins for it to sense OK?

I've just purchased a cheap Z820 that has a pair of liquid coolers on eBay, so I can investigate this a bit further.

Cheers,

M

[DGroves]

no, on either system there is no indication, (meaning it's working as designed) 

on my z820 with dual 130 watt e5-2699's v2 (and the latest bios)  i do not get a error when using the upgraded 3 heatpipe cpu coolers, (but did with the e5-2687w 150 watt CPU's)

however when pushing the system at 70% load i will hear the case/cpu fans ramp up quite a bit under prolonged operation

look at the link i provided regarding the pinouts of 3/4 pin pc  fans

this will allow you to id which pin on the z820 is the +12v

you do not want to short this 12 volt line to any other pin like ground or sense

which is why i recommend on the z820 using small 3 pin fans on the aux AIO header and skipping the vapor coolers shorting of the pins if you get any bios error msg on boot regarding the cpu cooling