No fan control on Z640 with Windows 10

[wavetrain]

The Z640 definately has the correct riser heatsink - just verified that. The fans are both working - verified visually. Maybe I should just pull the riser assy and see if it has CPU fan control with CPU0 (without CPU1). If the fan speed remains at idle regardless of the CPU temperature, I still have the same problem.

Maybe I'm all wet, but I sure think I should be seeing an increase in fan speed as the processor heats up. CPU1 may be heating up more quickly than it should, but I would expect the system to try to address this via the fan speed.

[SDH]

You'll get there... the HP fans control system has always been a bit of a mystery. I'm hoping you have also checked for a functioning front case fan (which was not present in all Z640/Z440 workstations) and also that the rear pair of case fans are working fine too.

I note on review DGrove's statement above that "your  installed  E5-2667 v4 cpu's max Tcase is 78c any higher will cause the cpu to throttle down in speed" so maybe it is that instead of boosting all the fan's speeds the expected response in your situation is that the CPU will cool itself as much as it can by slowing down internally.

I agree... it is time to pull that riser and see how things go. First just work with the single CPU0 processer that is on the motherboard currently. Then swap in the one that is on the riser to the motherboard's socket. Do that after the new thermal paste has arrived... just enjoy that Z640 running on CPU0 for now.

[wavetrain]

Down to CPU0 and 64GB RAM. Same issue. The CPU0 fan remained at ~523 RPM for the entirety of the CPU stress test, while the CPU temperature just kept climbing. I stopped the test at 80C.

Part of the disparity between the CPU0 and CPU1 temperatures in my earlier post may have been due to the fact that I ran the CPU stress test twice. CPU1 does not cool off as quickly, so hitting it with another test while it was at an elevated temperature over CPU0 skewed the resulting temperature differential between the two processors.

It's interesting to note that the CPU1 fan idles at over twice the RPM of CPU0, which indicates to me that the cooling for CPU1 is not as efficient.

"I note on review DGrove's statement above that "your installed E5-2667 v4 cpu's max Tcase is 78c any higher will cause the cpu to throttle down in speed" so maybe it is that instead of boosting all the fan's speeds the expected response in your situation is that the CPU will cool itself as much as it can by slowing down internally."

This really worries me. This Z640 shipped with a pair of E5-2623 V4 CPUs with a TDP of 85W. The upgraded E5-2667 V4 CPUs have a TDP of 135W. That's about a 58% increase if my old mind is still working at bedtime, and a lot of additional heat to dissipate.

If it's up to the CPU to throttle back at >78C, I have no idea just how hot it will get. I've stopped testing at 85C at the upper end, and it may go even higher. Guess I could buy another pair of CPUs for $50, and have spares on hand if I fry one. That's way better than the $4,114.00 it would have cost for a pair at release.

If anyone reads this who happens to have a Z640, if you could run the Device Check/Processor/CPU Stress Test in HP PC Hardware Diagnostics Windows and use HP Performance Advisor/Your Computer/Block Diagram/Sensors/Refresh Sensors to see if the CPU0 Fan speed increases during the stress test, that would be beyond wonderful.

Worst case, I have a new motherboard on the way. Sure hope I'm not sitting here next week saying "Why the heck did they design something like this?" But wouldn't be the first time I've said that.

[SDH]

That could be it.

You mentioned a "sealed box" and never mentioned putting in two hot processors when the workstation came to you with two cool ones. Sigh.

You may have seen my prior posts about HP "mainstream" vs "performance" heatsinks/fans. The "performance" ones are for hot processors. Those terms are HP's. If the motherboard sees those hot processors in place without a "performance" set of heatsinks/fans it may not know what to do. Go to HP Parts, enter your country code, enter the correct name of your workstation, enter the correct product number, find the parts, find the mainstream heatsinks/fans and know that those are now not what you need. Now go find the right ones. Hint: the product number will be different from what you currently have. The google will know.

Then, let us know what they are.

Or consider stepping back to two cooler processors.

[wavetrain]

I downloaded and read the QuickSpecs, and Maintenance and Service Guide prior to upgrading the CPUs. Nowhere does it mention anything about optional heatsinks. Processors, yes.

An hour of Google searching revealed two other part numbers from resellers... 782501-001 and 749554-001. Besides what's in there now. Both of these appear to be CPU0 heatsinks.

A Google search for Z640 high capacity and performance heatsinks returns nothing of value.

https://parts.hp.com/hpparts/Default.aspx?mscssid=DB4447E2FA87406CB3190030E295B8A9

Search for 749554-001 = A match cannot be found.

Search for 782501-001 = COOLER 1-CPU ONLY PERF Z440 Z640 ***SEE COMMENTS***

Search for Product No Z2D75UP#ABA = A potentially dangerous input was detected from the client browser.

Search for Z620 - Returns hundreds of alpha numeric parts codes.

https://partsurfer.hp.com/partsurfer/

Search for Z640 = All returned results are for Z840.

Search for Product No Z2D75UP#ABA = No additional information found in PartSurfer.

Search for 749554-001 = No additional information found in PartSurfer.

Search for 782501-001 = Central Processor Unit (CPU) cooler/heat sink assembly (lists as used in the Z440).

COMMENTS

So we seem to have a 782501-001 COOLER 1-CPU ONLY PERF Z440 Z640. After looking at a picture of this cooler, it is wider than the installed part. Perhaps the 1-CPU ONLY means that if you put it in a Z640, the second CPU card won't fit. So this essentially turns your Z640 into a Z440. Nice.

So why wouldn't HP put this in the documentation if it were the case? Seems like a pretty important omission to me.

Apples and oranges, but I installed a pair of E5-2667 V2 CPUs in my Z620. Higher TDP than the ones they replaced. Have the original heatsinks in there that came with the computer (and slower processors). Found no information that it needed special heatsinks - just like the Z640. They work fine. The fans speed up automatically. The processors don't overheat.

So HP designs a replacement for the Z620. It's called the Z640. Very similar layout. I installed E5-2667 V4 CPUs. Found no information that it requires special heatsinks. It has no fan control. Manually stepping up the fan speed in BIOS keeps the processors from overheating, but it's noisy. The Z620 is noisy when it needs to be, but the Z640 just cooks the processors - even when the heat sinks are perfectly capable of supporting them, if only it would increase fan speed. So HP offers a big whopper heatsink, but you loose a CPU. And half of your RAM. There's always 32GB modules to get you back to 128GB, but you still end up with a Z440. This is just crazy to me.

Here's a link to a review of a Z640 with the same processor configuration I have. It even includes an internal picture, with what appears to be a stock CPU0 heatsink. I'll assume the CPU1 heatsink is stock too, because there isn't any extra room under the cover. So am I really crazy or negligent for not finding the unicorn heatsinks?

https://www.storagereview.com/review/hp-z640-workstation-review

Common sense guys. The fans should speed up when the processor heats up.

[SDH]

I'm pretty much out of ideas.

PartSurfer if you enter HP Z640 in the generic search box gets you a huge number of Z840s and then comes the Z640s at the end. Strange. Change bottom left to 50/page and use the double right arrows at bottom right and you'll see 301 pages of 50 each. The problem is you would need to know what the product ID is of a Z640 that officially came with the processors you want to run to then see its particular parts there. The concept of a HP "Performance" heatsink/fan is nothing new. I've never seen those detailed in the service guides but you could see the different part numbers if you looked in PartSurfer and those had more fin surface area, more heat tubes, a bigger fan, more cost, and harder to find. I admit to never seeing one on eBay for the Z640. The Z440 has its big double-surface area fan that I use in our single processor Z620 builds.

Agree with your frustrations. Maybe you should just try using it normally rather than for stress testing. We here don't have any Z640 that was bought from HP with your new processors installed as a build to order. Maybe it is the motherboard? Maybe you're supposed to use a HP "Vapor" cooler with those processors, but I've never seen one made for the Z640. Maybe your stress testing program interferes with the usual function of the motherboard in the Z640 but not the Z620. I doubt it. 

None of ours overheat but we don't generally do stress tests either. If I come up with any added info I'll post back. Attached is a unicorn for you... which I don't think will help at all.

[DGroves]

i think you need to step back a bit and start from the basics

1. remove the riser all testing will be done with it removed

2. install the original cpu in the system and boot, then install 

HP Performance Advisor for workstations

https://www.hp.com/us-en/workstations/performance-advisor.html

use this app to check the cpu temp and cpu fan speeds at system idle, with the app still open download an run the sysinternals cpustress program (set it for max threads/cpu load) and then monitor the **bleep** app temps let it run till the cpu hits 70c and note if the cpu fans increase in speed (ignore the case fan speed)

note that "heavyLoad will also do the same type testing"https://www.softwaretestinghelp.com/computer-stress-test-software/#:~:text=HeavyLoad%20is%20a%20Free....

https://learn.microsoft.com/en-us/sysinternals/downloads/cpustres

if the cpu fan does not increase in speed by itself you can try replacing the motherboard

if that makes no difference then the issue is most likely something that you are doing wrong and not realising it

[wavetrain]

Sorry, caught up on other things until this morning.

Installed the new Z640 motherboard. Very easy swap. Did my homework, and used the HP BIOS Configuration Utility sp143621 to create a config file from the original motherboard first. Everything came right up with a “System is booting in manufacturing programming mode. 26 boots before lock.” message displayed at the top of the screen. Installed the latest BIOS from USB, and after restoring the previous BIOS configuration, all is looking good.

Only have CPU0 installed, but 72C is as hot as it will get. That’s after three back-to-back CPU stress tests. The CPU0 fan is at ~523 RPM, and has remained there during the test. Finally, some good news.

Installed the second CPU daughterboard, and trying again. Still have a problem with this one. CPU1 finished at 86C and 1230 RPM. The fan speed remained at ~705 RPM until the temperature reached 85C.

Fan control on the Z640 seems to be reactive vs proactive. Looks like it’s designed with heatsinks and fans that they expect to do the job at a low fixed speed. Fan speed will increase, but not until the system detects a problem.

I’ll order another pair of CPUs, and replace CPU1 to see what happens. Best guess is the CPU or the heatsink at this point. Whoever said CPU earlier in this thread may have nailed it.

CPUs are both happy at 30C as I write this. Thanks so much to everyone for their thoughts on this. Way more involved than I would have liked, but have a better understanding of the machine as a result. Will update when I find something.

[DGroves]

you are correct, the hp thermal cpu system is geared to only increase fan speeds gradually depending on the cpu tems and as i recall it has 5 or 6  speed steps

[wavetrain]

A few more thoughts on Z640 CPU cooling…

Ran Cinebench R23 to take another look at how the CPUs behave under stress. This benchmark repeatedly renders an image over a 10 minute period. It pretty much maxes out all CPU cores during testing, so this is a good representation of high loading.

CPU1 definitely gets hotter faster, leading CPU0 by 10 degrees C or so. I have been using the Sensors function of HP Performance Advisor to monitor temperature and fan speed, but now I’m doubting the accuracy of what’s being reported. In the past, I’ve used a program called Speccy to look at CPU temperatures. It allows you to see the individual cores, and provides an average temperature for each CPU. HP Performance Advisor provides higher numbers, but not sure why. Under full load, Speccy reports temperatures of 84 and 83C. This is a hot as it gets. HP performance advisor says 87 and 88C. Is HP looking at a different sensor?

Fan speed is ~522 and ~713 RPM at idle, with CPU temperatures of 31 and 31C (Speccy) and 38 and 38C (HPPA). Fan speed is ~804 and ~1633 RPM at max CPU temperatures of 84 and 83C (Speccy) and 87 and 88C (HPPA).

So judging from HP’s fan speeds when they finally ramp up, and the observed heating of CPU0 vs CPU1, I think it’s safe to say that CPU1 is not dissipating heat as efficiently as CPU0. The large disparities between CPU temperatures may be normal.

I have a pair of CPUs, a new CPU1 heatsink, and some recommended thermal paste on the way. Thankfully parts for these are quite reasonable. If I end up with the same results, it’s all just normal behavior. Will be the first HP workstation I’ve owned that can’t keep supported processors within their recommended operating temperatures, but it’s certainly faster than the Z620 it replaced.

For most of what I do, the cooling issues won’t be a problem. But some seemingly simple tasks (like a Windows virus scan) will push processor temperatures beyond their recommended limits.

Here it is…

Just installed another used E5-2667 V4 as CPU1, a new CPU1 heatsink, and applied Noctua NT-H1 thermal paste to both CPUs after cleaning everything thoroughly with 91% isopropyl. Fan speed is ~737 and ~1825 RPM at max CPU temperatures of 85 and 84C (Speccy) and 87 and 89C (HPPA). So nothing significant to report after the swap.

I feel pretty confident in saying that the Z640’s design just can’t effectively dissipate 270W of CPU heat (135W x2). Even though these processors are on the supported list. I guess if you were expecting to load the CPUs for an extended period, you could crank up the idle fan speed in BIOS and live happily (and noisily) ever after.

It’s still a relatively good performing computer, so no regrets here. Worst case, I have a couple of spare CPUs. The thermals just aren’t what I expected based on other HP workstations I’ve used for years.