Undervolting tutorials?

Scott

Behold The Ford Mondeo
Moderator
I have a 3900XT, so a step down from you. My other components are; an X570 and H115i AIO, with a 2080S, in a Corsair 680x case.

I've just tested on Prime95 and my max temp was 78°C, with an average of 76°C and an average clock across all cores of 4215Mhz, and showed 87% average usage.

I also ran the BMW and Classroom render on Blender, 56 and 163 seconds respectively - max temp 67°C.

I don't see any issues with mine and I'm not sure how or why I'd want my temps and/or performance to be any different.

Now that's the sort of figures I would expect to see.

Do you recall the setting you had the H115i on?
 

Scott

Behold The Ford Mondeo
Moderator
The pump is on balanced and i have a custom curve on all of the fans, the H115i fans are based on the water temps.

Thats even better than. Great to have some real world figures for the h115i rgb and the 3950x. Considering thats the default curve thats something else 😎
 

JohnWalton981

Silver Level Poster
Thats even better than. Great to have some real world figures for the h115i rgb and the 3950x. Considering thats the default curve thats something else 😎
I'm very impressed with it. People say the pumps are loud but I can't hear mine. I have a "quiet" profile in iCUE with the pump on balanced, 3 of the 5 intake fans off and the remaining case fans running on 500rpm - 800rpm, you wouldn't know it's on. As i write this with just Chrome open the CPU is at 40 °C and the H115i, which I assume is the water is at 29 °C.
 

AgentCooper

At Least I Have Chicken
Moderator
I'm very impressed with it. People say the pumps are loud but I can't hear mine. I have a "quiet" profile in iCUE with the pump on balanced, 3 of the 5 intake fans off and the remaining case fans running on 500rpm - 800rpm, you wouldn't know it's on. As i write this with just Chrome open the CPU is at 40 °C and the H115i, which I assume is the water is at 29 °C.


I wonder if you change from Chrome to Firefox, will you see the CPU temps dip even lower? Chrome comes across as such an unnecessary resource hog 😑
 

edgetrading

Bronze Level Poster
Hi John. Thanks for sharing your stats. Since my previous post, I discovered that there is a Blender Benchmark tool, which is better for providing consistent results for comparison. The figures I gave above are for manually running it from Blender 2.79b.

The Blender Benchmark tool is here: https://opendata.blender.org/

You can also see what results other users achieved. For example, for the 3900XT, we'd expect around 120 seconds (see here). Were you rendering using the GPU? Your results seem in line with GPU rendering with CUDA here.

So, using the Blender Benchmark Tool to run the tests again, using these settings:

Blender version: 2.90
Device: "AMD Ryzen 9 3950X"
Ambient temperature: 21.1C
OS: Ubuntu 20.04
CPU at stock settings
CPU fan at 40%
Case fans (2x120mm stock fans, + 2x140mm Noctua AF14's) set as low as they will go.
Computer is definitely not silent, but is very quiet.

Results:

BMW27: 82.12 seconds Max temp 60.2C. But looks like it would have got hotter if it had gone on for longer as temps were slowing rising.
Classroom: 228. seconds. Max temp 62.0C (looks like it had plateaued here).

As an irrelevant aside, what do you think of your case? I think it looks very cool and considered getting it, but it's a bit too wide to fit comfortably on my desk.
 

JohnWalton981

Silver Level Poster
I was on GPU looking at it. I've ran it again on CPU only as you say the times are more in line with other 3900XT and the temps were 72 °C.

The case is indeed a fat-lad, I had to get a new desk to accomodate it. It's very good peformance wise and with the PSU, SSD and cables all in the back it's extremely neat too.
 

edgetrading

Bronze Level Poster
You're lucky you have the desk space!;)

I have the Meshify C case. On Amazon reviews, there are a few complaints that it's hard to even close the case due to lack of cable space. However, PCS did an exceptional job at keeping things neat and tidy, and I can shut the case without problems.

However, this forum has given me an unhealthy obsession with temps, and I've ordered another couple of 140mm Noctua fans to put in it. Hopefully I can do that without making the case impossible to close. Conventional wisdom says they probably won't help. But I just want to see what happens anyway as an experiment.
 
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