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Microsoft Windows 10 (64-bit)

I spent yesterday digging through some old posts about overclocking, modding for additional USB3 ports and generally reading up and learning about the Zx20 Workstations, downloading programmes and then playing with overclocking in line with best practice.

What a great day!

It all started when I decided to investigate fan control  and I found this post:-


Some great points by SDH. I downloaded the HP Performance Advisor and it is indeed a fantastic piece of software which illustrates nicely the relationship between processor and chipset and what controls what. Very useful.

I'll get to the cooling in respect of overclocking in a moment but I have just bought the nice Z440 fan with the opposing singular screws and that will arrive this week.  It will be interesting to see if it reduces temperatures compared to the standard HP liquid cooler setup.  If so, there is a nice profit to be had in selling the pumped setup!

I wonder if you ever reconciled whether the standard HP Pumped Water Cooler was more or less efficient than the 749554-001 heatsink as mentioned here:-

Some nice photos there of the Mouser parts for the conversion of Zx40 to Zx20 pinout.  Unfortunately Molex 22-01-3057 is on a 32 weeks lead time with my usual electronics supply and 13 weeks with another.  I can just hand the connector end out in space I guess for now.  In your photo, you have handwritten the code MXN-20-2695.  2695 is the Molex Series but I cannot find what MXN-20 refers to in any catalogue.


I have a front case fan in the machine I am looking to overclock.

That Noctua NH-U9S is one sexy looking fan (I might be losing the plot here...) and currently £54.99 in the UK. I wonder how this would compare to the 749554-001 in terms of performance and surface area and also the HP Pumped Water Cooler.  I feel sure you will have by now researched this and have a definitive answer on that subject?  I have some interesting anomalies which I will mention later in this thread between the two Z420's I now own.

Coupled with the NA-FC1 Fan Controller, which looks a nice piece of kit, I would have a readily controllable system for overclocking.  I wonder whether .@BambiBoomZ bothers with this on his setup.  Brian1965 does not need to with his monster system.  That is simply incredible.  If it's not a typo, his system runs at 0 degrees C?  Hardly surprising with his n litre header tank of ethylene glycol or whatever coolant he uses!  Pure genius 😂.  However, I do not need to go that extreme or is this the slippery slope?

I am quite happy with the results I achieved in overclocking yesterday and I hope .@BambiBoomZ will verify I am on the right track.

Whilst overclocking, I managed to get to 4.4Ghz with fans on full tilt via BIOS reboot but as soon as I increase even Core 1 to 4.4Ghz, it instantly fell over. Interestingly, I can increase voltage to 15mV and it still appears to be stable and the temperatures do not increase that much.  Sometimes reducing the voltage improved the CPU mark.

My highest PassMark now is:- 4680
This was achieved at 4.3GhZ on all 6  cores with a 100mV boost.  Highest temperature observed was 67degC but only on one iteration of Performance Test.  Peak power of 154.46W and IA Cores was 145.61W.

An attempted overnight test failed so what caused it to trip out if not temperature?  Is there a way in CPU ID HW Monitor to simultaneously save a live data stream or record of highest temps / wattages so that if it does turn off, I have a record to analyse?  Or is it a game of patience?

At one point, I did ramp up to 1.521V and it was stable but again only for a short while.  


I found this super reference iro Driver Packs:-

I guess HP stopped validating drivers at Build 2004 if my understanding from the chart is correct.

I have version 4.3 installed of the Intel(R) C600 Series Chipset SAS RAID (SATA mode) driver.  Being on Windows 10 21H2 would I benefit from upgrading this to version 4.6..

I installed NVidia 472.49 drivers for the Quadro K2200.  Would I benefit from installing all drivers and deploying the SP99374 driver pack which would downgrade the NVidia drivers to version 419.17?  If it is working as is, presumably any noticeable differences in downgrading to the last supported and presumably validated HP driver pack would manifest themselves, or not as the case may be, in performance increases in Performance Test on the graphics test? I appreciate this is perhaps scratching for a performance increase when other simpler solutions are available to me.  It's just a case of wanting everything to work as symbiotically as it can by using the best available resources as efficiently as possible.

Whilst reading other posts about upgrades and mods, I did an Ebay search and noticed I missed some HP 665812-001 parts on Ebay 3 days ago only £24.99 + £3 postage!!!  This is the HP USB3 Card.

Whilst looking for 661320-001 and 663213-001 Newer HP USB3 card, I also noticed that there are some naughty Ebay sellers are using the part numbers for the "Renasus" version and "2x2" also. Got to be careful to buy oblong version of card with Texas Instruments chip.

Got to get on and do some exercise now but will post at some point about the other Z420 which is seemingly not going above 1.041V and seeing massive 90degC temps on a relatively low overclock.  All BIOS settings appear to be correct so was wondering why it is not seeing 1.3V in CPU ID??

HP z420_2: (2013) (R1) Xeon E5-1650 v2 (6C@ 4.3GHz) / HP Z420 Water Cooler / 64GB (SK Hynix 4X 4GB DDR3-1866 ECC registered) / NVIDIA Quadro K2200 4GB / Samsung 870 Evo 480Gb / 600W PSU > Windows 10 Professional 64 bit > HACer KG271 1920 x 1080
[Passmark System Rating: = 4680 / CPU = 15259 / 2D = 620 / 3D = 3992 / Mem = 3038 / Disk = 5464 / Single Thread Mark = 2338 [Performance Test 9.0 Evaluation Mode]


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You're doing a lot of work here... don't neglect your Austrian mate!  Yes, Bambi and Brian are in a class all by themselves.


I have not bought a Bambi type HP Z420 liquid cooler and have not gotten into overclocking much because we need to only use W10Pro64 at work and OC does not appear to work under W10.  Maybe someone can chime in and tell us how they got the Intel utility to work on W10 if they ever did?


I suggest:  Make sure to always turn off Fast Startup if you make a W10 build to try overclocking on.  It is not a BIOS setting; it is a W10/W8 operating system item.  It is defaulted by Microsoft to ON in W10 and caused us significant issues until I discovered it was doing that and learned how to turn it off.  Let me know if you need a little HowTo on that.  I like my way best.


I have not compared the HP Z420 water cooler to my HP Z440 heatsink/fan solution.  On my first work with installing that I found it fits perfectly in each Z420 and in all single-processor Z620 builds.  We only use version 2 of those workstations but I'm quite sure it would work fine in version 1 boxes also.  It fits under the "saddle-like" device that was designed to be used in any Z620 single-processor workstation.  It provides a small cooling fan over both the front and rear memory banks (look on eBay for 644316-001 or 644317-001 to see one, but these don't fit on a Z420).  There is just enough room to slide a few stacked Post-It notes between the top of the big Z440 heatsink and the bottom of the saddle's top bridging black plastic.  Bambi mentioned his liquid cooler is not a perfect fit under that bridge, but it sure looks good to me from his pictures.


The Mouser parts.... I did that first as your linked post shows with the Mouser parts.  That is a fiddly process, and also a waste of time.  Then I realized I could just take the original ZX20 fan with its standard 5-pin plug end off of the Z420/Z620 heatsink and transfer it over to the Z440 heatsink and it works just fine.  Then I finally realized I did not even need to do that.  The only thing I now do is install the big Z440 heatsink with its original fan/6-pin plug end still attached and have that 6th pin hole shifted off to the side from the 5-pin ZX20 CPU0 fan header.  That sticks out about 2.5mm.  There is nothing in the way on the motherboard, and no risk of having a ground short by doing that.  Thus, "plug and play" with that approach.


Regarding Noctua heatsink/fans... the HP PWM control system built into the motherboards is engineered to work with specific HP selected PWM fans.  You'll generally find using Noctua (or other brand "quiet" same-sized) PWM fans will end up running too slow and providing too little cooling when driven by the HP motherboard.  If you found a Noctua heatsink you really like and it takes the same size fan that the HP heatsink uses (92 x 25 mm) I suppose you could try that.. replace the Noctua fans with two of the HP ones.  Personally I think that would be expensive and a waste of time given your HP water cooling solution or my Z440 double-big heatsink option.


I noticed in one of my old linked posts above a broken link to the more recent HP memory PDFs that are so hard to find.  I'll post again to this thread shortly and attach those... I'll try to combine all 6 into one PDF.  Officially the memory that HP recommends for the Z420 is different from the Z620 recommendation but the exact same retired server memory I've posted about that we use for our Z620 builds (ECC, Buffered, 1866 MHz) works perfectly in all of our Z420 v2 workstations.  I built up about 25 of those a while back... zero stick failures using the 8GB size sticks (using either 4 x 8GB or 8 x 8GB builds)... at about 11-15.00 USD/stick with good eBay hunting skills.

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Just a quick response as I am on my iPhone. 

I had noticed that those PDF’s were no longer working. Sorry. I meant to mention it to you. 

I seem to have XTU working on Win 10. 



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"I suggest:  Make sure to always turn off Fast Startup if you make a W10 build to try overclocking on.  It is not a BIOS setting; it is a W10/W8 operating system item.  It is defaulted by Microsoft to ON in W10 and caused us significant issues until I discovered it was doing that and learned how to turn it off.  Let me know if you need a little HowTo on that.  I like my way best."

I cannot see how to use quotes on this forum.  Anyway, I just disabled Fast Startup in Power Button settings.  Not sure what other way there is to do it other than CMD prompt perhaps?

I never realised there was this additional 'saddle' until today. When you say "(look on eBay for 644316-001 or 644317-001 to see one, but these don't fit on a Z420)."  Do you mean neither of those will fit or only the 644316-001will fit a Z420? Reason I ask if the guy I have bought the Z440 off also has one of these shrouds.  Was there a specific one for the Z420 which would actually allow the Z440 fan inside it?  It would be lovely to have all the nice cool air flowing exactly where it was designed to.

Leaving the side of my PC off probably results in higher internal temperatures whilst I am fiddling.

Fair comment on the Molex connector.  I had read DGroves say just hang the connector over into thin air.

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That "saddle" will only work on a single-processor Z620, never on a Z420.  From that era HP provided an Assembly and a Spares part number, for same item.  Ignore all this unless you end up buying a Z620 and plan on running it on only one processor.  We bought a few Z620 v1 boxes way back that were on closeout from HP that had low TDP processors before I knew what I was doing and they did not even come with the memory cooling saddle from the factory.


There is no such "active cooling" saddle for a single processor Z640 or Z440, or a Z420.  I tried all that.  There is a "passive" airflow baffle that I always use for my Z420 hot builds to cool the front memory bank.  And, its purpose is to pull cool air from the front of the case up over the front memory bank via the suction of the power supply's single fan.  Works well for that purpose.


I have archived those memory PDFs... I now just need to see if when I aggregate them that the end result fits in this forum's cutoff for size.

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Oh, hey, HP engineers have clearly stated that leaving the side cover off results in worse rather than better cooling...  the whole box was engineered to cool best with the cover on.

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OK. Just had to double check what I had previously read up on that as I did buy the front shroud for the first Z420. 2nd unit came with one.  Managed to get one for £15 shipped! 

i wasn’t sure whether our friend DGroves had mentioned that shroud to me or yourself.


I think there is some hope that I will get close to BambiBoomZ passmark result one day. 

And then it will be time to move onto a v3 or v4!

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If you have the overclocking going under W10Pro64 please post how you did that, with specifics on which version of XTU you chose to use and any tips and tricks.  I'm assuming you turned off Fast Startup in W10 and also are running those BIOS settings I sent you to keep Turbo enabled.  Thanks... I'm interested.  I could make a clone of one of my Z420 builds and experiment with that and capture some temps with HWMonitor while running under one of those Z440 extra-large heatsink/fan CPU coolers... I've shifted all my personal Z420 and Z620 builds over to those.


Attached are the PDFs of the HP DDR3 and 4 memory I promised, and one Binder of them all, below...   I just checked again and they are impossible to find via HP.  Paul T may know some search tricks I don't, however.


Note that for the Z420 HP details a lesser memory than I have found to work perfectly, which also works perfectly in the Z620 v2 and the Z600 v2 workstations.  However, if HP does not do the extensive testing to validate a piece of hardware they won't list that item officially even if it works perfectly for us all.

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Hi .@SDH 

I am on BIOS J61 v3.96 for starters but I am sure you will most likely be also.

The very first time I downloaded XTU, I did so using 7.6.??? and it didn't look very configurable.

So I've ended up with from HWBot site.  Here is a link to it in OneDrive:- https://1drv.ms/u/s!Ar8AkvzZJWl9hoIPvtH7uG1PgCkRKg?e=yJGmKO 

After much reading up, my initial confusion about using it has been banished.  HP have a pretty much locked down BIOS so you are only able to edit the Multipliers and the Additional Turbo Voltage in Manual Tuning.

Ensure you have Watchdog switched on in your BIOS.  You will have as they were part of the settings you kindly provided to me.  The Fast Startup doesn't affect it.  Having said that, it may do but I haven't switched it back on since switching it off yesterday.

Due to you questioning this, it did make me wonder if the settings persist after reboot, so I have literally just altered the multipliers and applied them under Manual Tuning and rebooted and they were still the same upon opening XTU again.

Interestingly, I'll bet if you are unable to succeed with it that there will be a setting that I have enabled that I have not knowingly consciously changed and that I will therefore not be able to advise you of.

I am on Windows 10 Pro 64 21H2 build with all updates to January 2022 installed.

I say this because today I have reinstalled a printer driver for our Zebra GK420d thermal printer and can I get it to print to the same quality as the version (which is the same driver version) on the old hard drive?  NO!  So frustrating, the print quality is verging on abysmal and yet I have switched hard drives today.  I can print on the old hard drive perfectly. It is crystal clear.  Switch to clean install with same drivers, same settings and the print quality is shocking compared.  Another thing that is driving me nuts!

15th anniversary today so we celebrated with Fish and Chips... 😁

PS The RAM Doc is very useful. Thank you very much.  Need to tag your post though so I can remember whether you use buffered or unbuffered!!!

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Fish and Chips sounds great!


It will be some time before I can to XTU experimentation but thanks much for the version info that works with W10.  I'll get back to you later on that, and will download that now so I have it in my stash.


We only use ECC buffered on our HP workstations at work because there is a bit of added data protection gotten by that.  There is a minute speed cost to that but for servers and medical work buffered is the only way to go.  I have never detected any speed benefit from using unbuffered and even for our home computers I look at data integrity as something to set highest on the priority list.  So it is ECC buffered for us 100% at home too.


For future readers:  We only run version 2 of our Z420/Z620 workstations and the same ECC buffered recycled server sticks (1866 MHz speed) that we use on the Z620 v2 works perfectly on the Z420 v2 workstations.  Note that HP recommended unbuffered in the Z420 but buffered in the Z620 in those pdfs.  We don't follow that.


The amazing thing to me is that those same sticks work perfectly also in the Z600 v2.  They will not work in the Z400 v2, however... different memory controller in that.  In the Z600 v2 the memory controller down-regulates the memory speed from 1866 to 1333 automatically to match the fastest speed of the processor(s) we use.  We still have a few of those around... work horses still when they are souped up!



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