you have to do some sort of high end water loop. that just for the cpu. with a massive radiator

If you want to run the 3900X at something close to its core clock spec, you need water cooling for a 24/7 compute load. I have mine set at a fixed all-core clock of 4150Mhz which is where the cpu would run at on Auto if it had to run compute for 24/7. But I do it at a lot less voltage than what Auto shoves into the chip.

No need water cooling but need a really decent aftermarket cooler. I am running 3900x on auto (comes to ~4.1GHz on all core load) but with negative voltage offset -0,1V, so effectively ~1.23V CPU voltage, fully stable and full performance at just ~72-73C with Noctua NH-D14.

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you have to do some sort of high end water loop. that just for the cpu. with a massive radiator

If you want to run the 3900X at something close to its core clock spec, you need water cooling for a 24/7 compute load. I have mine set at a fixed all-core clock of 4150Mhz which is where the cpu would run at on Auto if it had to run compute for 24/7. But I do it at a lot less voltage than what Auto shoves into the chip.

No need water cooling but need a really decent aftermarket cooler. I am running 3900x on auto (comes to ~4.1GHz on all core load) but with negative voltage offset -0,1V, so effectively ~1.23V CPU voltage, fully stable and full performance at just ~72-73C with Noctua NH-D14.

Well you are doing very good then. Smart idea to use a negative offset. That voltage is about where I end up on Vcore too. ~1.24V.
You are getting very good temps. Better than my custom water cooling. You must have very good case ventilation.

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

Keith, are you running the GPUs in the same loop as the CPU? That could be why.

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Seti@Home classic workunits: 29,492 CPU time: 134,419 hours

Keith, are you running the GPUs in the same loop as the CPU? That could be why.

No the custom loop is just for the 3900X. I don't know why I have such high temps. I need someone else with a custom loop and the same amount of radiator to tell me what their delta from ambient is to compare against mine.

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

I'm doing about the same.

Auto, drop vcore offset to -0.05 and a Noctua fan U14S, but i've disabled SMT.
I do not need the extra 12 cores. I just want as full speed on the single threading as possible as it is powerful enough.

My cpu @ 24 cores = 70xx Cinebench and the cpu @ 12 cores = 50xx Cinebench.

The cpu is almost always below 70 degrees Celsius (Except with prime95) and turbos up to 4.5 - 4.6 region on one core as intended. Running the ABBA bios.
Cannot really hear the fan as it's dead silent and i've adjusted fancurves in the bios that it doesn't throttle until 70 degrees Celsius.. Its so silent even at 100% usage.

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_________________________________________________________________________
Addicted to SETI crunching!
Founder of GPU Users Group

The cpu is almost always below 70 degrees Celsius (Except with prime95) and turbos up to 4.5 - 4.6 region on one core as intended.

Ambient temperature?

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Grant
Darwin NT

I have been watching the prices for a 3900x on eBay. They have dropped to $550 for the most part. Either things have "caught up" or the threat of getting the 3950x finally released has dropped the demand.

Tom

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A proud member of the OFA (Old Farts Association).

Certainly ambient temperature???


For those that have been following the "big beast" I've been working on for a few months, this machine is air cooled, using chilled, dried air (~5C, an <10%rh) to cool the entire system - right down to the extent of "wind-tunnel" style ducting to all the processors (and there are hundreds of them when one counts all the GPUs, CPUs, comms processors etc.). With the 5C ambient and air-blast on the heat sinks liquid just isn't needed in the primary loop.

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Bob Smith
Member of Seti PIPPS (Pluto is a Planet Protest Society)
Somewhere in the (un)known Universe?

My ambient is about 20 - 22 degrees Celsius. A 2080Ti in the same system.
And i'm running it in 12Core mode (Not 12 core + fake to get 12 more cores)

My system (12 cores): https://setiathome.berkeley.edu/show_host_detail.php?hostid=8600449
Keiths system (24 cores): https://setiathome.berkeley.edu/show_host_detail.php?hostid=5741129

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_________________________________________________________________________
Addicted to SETI crunching!
Founder of GPU Users Group

Running without SMT certainly explains it. But at the cost of about 50% or more potential performance.

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Seti@Home classic workunits: 29,492 CPU time: 134,419 hours

Running without SMT certainly explains it. But at the cost of about 50% or more potential performance.

Yea, around 40% in multithreaded applications, but with higher performance in some single threaded applications instead.

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_________________________________________________________________________
Addicted to SETI crunching!
Founder of GPU Users Group

Well my high temps on my custom water cooling can be somewhat explained by my ambient which is 28° C. But I still have doubts about the cooling. I probably will pull the block off once again to check the paste spread. I think the difference between the amount of surface area of the IHS of the Ryzen compared to the Threadripper has a lot to do with it.

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

How long has the loop been in service? When was the last time you disassembled the block to check for any flow blockages? Might have some funk buildup if it’s been a little while.

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Seti@Home classic workunits: 29,492 CPU time: 134,419 hours

It only has been in service for a couple of months. Already took the block apart once to check for blockage. Clean as a whistle.

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

Silly thought - is the pump working properly?

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Bob Smith
Member of Seti PIPPS (Pluto is a Planet Protest Society)
Somewhere in the (un)known Universe?

Silly thought - is the pump working properly?

That is what I am wondering. But I can't tell if it is or isn't. I don't have a flowmeter in line with the tubing. When I drain the system and refill it, it rapidly pushes fluid into the loop so the pump is working at that point. I do know what happens if the fans on the radiator get stopped. The radiator and the fluid in the reservoir rapidly heat up and then the system reboots with a cpu temp overheat error. That is what I found out about the original BIOS for my board and cpu. All the fans on the motherboard headers would just stop. That forced me to remove all the fans from the motherboard and install a fan controller hub independently powered by the power supply. I can feel the vibration in the pump/reservoir when I put my hand on it. But to actually verify if the pump is moving the normal volume of fluid around the system I think I would have to install a flowmeter. I have swapped blocks twice already and it made no differences. I don't know whether buying the Heatkiller IV block would be wasted money or not. I have two very good blocks already now. The XSPC Raystorm Pro and the AquaComputer Cuplex Kryos Next Silver block which is what is on it currently. The blocks themselves are all metal, so I would think if the fluid flow is low, then the blocks themselves would be hot to the touch because the conducted and transferred heat from the IHS would equilibrate into the blocks. But the blocks are barely warm to the touch. Not much different in temperature to any of the surrounding metal of the chassis.

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

Techpowerup has an article purporting a screenshot from the Ashes of the Singularity game showing a Threadripper 3960X cpu running. That is the supposed 24core/48T Threadripper to be released next month. Also news that the new motherboards using the TRX40 chipset would have a new socket designated, "SP3r3", which would be the 3rd generation of the Threadripper socket. The present socket on existing X399 motherboards is designated "SP3r2". Speculation is that the new sockets would allow 8 channel memory. The new cpus would only be able to be used in the new motherboards and the old Threadripper cpus would not be able to be used in the new motherboards.

https://www.techpowerup.com/260213/amd-ryzen-threadripper-3960x-a-24-core-chip-the-range-starts-with

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

To answer the question of adequate flow, I ordered a flowmeter that reports rpm and and has a table to convert rpm's to liters per hour. Should be here Saturday and I will tear the system down once again to install the flowmeter and check the cpu block once again.

The following values ​​have been determined Tolerance +/- 10%:
125rpm equal 190 liters / hour
150rpm equals 250 liters / hour
175rpm equal 320 liters / hour
200rpm equals 390 liters / hour
225rpm equals 450 liters / hour
250rpm equals 500 liters / hour

My pump puts out 600 liter per hour at 12V which is what mine is powered from.

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

Question for @Vyper, which of the cpu temp sensor readouts do you use? The motherboard SIO CPU Temp or the cpu internal Tdie temp? The motherboard CPU temp is only polled every couple of seconds and is an average over time. It only reports whole integers and the accuracy is limited by the LSB conversion of the ADC.

The Tdie temp is the millisecond polled, random, internal sampling of each cpu core and has accuracy to the half degree. That is the one I use. So depending on which cpu core gets sampled, the reported Tdie temp can be 68° C. if the core that is looked at has just become unloaded or it can report 83° C. if the core that is currently polled is under heavy AVX loading from a cpu task. So I see quite a bit of variance in the Tdie reported temp depending on which core is being looked at.

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

You are getting very good temps. Better than my custom water cooling. You must have very good case ventilation.

Reasonably good case ventilation yes, fans are TY-140, 2pcs for upper exhaust and 1 back exhaust, all nearly silent even under full speed.

But also Noctua NH-D14 is a awesome air cooler, price/performance better then all AIO water cooling system, even matching performance with entry-level custom cooling (at lower price point).

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