Ryzen 7 3800x (or 3700x) - Lowest temp under full load

[StDragon]

With a Ryzen 7 3800x (or 3700x), what's the lowest temperature you can maintain while under full load with Prime95 (Small FFTs for maximum power/heat)?

 

I've just replaced the stock HSF for a Dark Rock Pro 4 which is rated for 250w of heat dissipation. My ambient temp in the room is 25C (77F), but I'm reaching 88C @ 4.0Ghz maximum under load.

 

I used the included thermal paste and placed in an X pattern with a line running through it. Maybe the application didn't go through, or the included paste is crap. I'm not sure. I'm still waiting in the mail for my IC Graphite Pad to arrive in the mail, so I will test again once I get that installed.

 

I'm kinda worried that the heat transfer is limited by the TIM between the die and CPU lid.

[maxdei]

6 minutes ago, StDragon said:

With a Ryzen 7 3800x (or 3700x), what's the lowest temperature you can maintain while under full load with Prime95 (Small FFTs for maximum power/heat)?

 

I've just replaced the stock HSF for a Dark Rock Pro 4 which is rated for 250w of heat dissipation. My ambient temp in the room is 25C (77F), but I'm reaching 88C @ 4.0Ghz maximum under load.

 

I used the included thermal paste and placed in an X pattern with a line running through it. Maybe the application didn't go through, or the included paste is crap. I'm not sure. I'm still waiting in the mail for my IC Graphite Pad to arrive in the mail, so I will test again once I get that installed.

 

I'm kinda worried that the heat transfer is limited by the TIM between the die and CPU lid.

there is a hot spot on one of the sides beacuse all cores are there there is a good viedo from der8auer

[StDragon]

4 minutes ago, maxdei said:

there is a hot spot on one of the sides beacuse all cores are there there is a good viedo from der8auer

Do you have a link?

 

When I stop Prime95, the temps drop about 1C per second. Eventually it reaches its lowest of 43C at idle before undulating between 43C and 53C as the fan RPM adjusts accordingly.

 

But yes, you might be correct. There is a hotspot not directly covered by my paste application. Hence the high temps and relative slow cool down period. This HSF is MASSIVE with lots of thermal mass. The air is not even warm. So clearly the issue is between the CPU and HSF someplace IMHO.

[maxdei]

3 minutes ago, StDragon said:

Do you have a link?

 

When I stop Prime95, the temps drop about 1C per second. Eventually it reaches its lowest of 43C at idle before undulating between 43C and 53C as the fan RPM adjusts accordingly.

 

But yes, you might be correct. There is a hotspot not directly covered by my paste application. Hence the high temps and relative slow cool down period. This HSF is MASSIVE with lots of thermal mass. The air is not even warm. So clearly the issue is between the CPU and HSF someplace IMHO.

will search for it 

 i can not garante that i find the video in englisch but it should have subtitles

i watched it in german but should be avalable in englisch too

 

found it in english

 

forgot just works with custom or aio but why should the temps be a problem

 

[StDragon]

Thank's Maxdei, very informative.

 

Yeah, I think I'm just going to wait for the IC Graphite pad. I've used on for an Intel i7 before, and it cools really well; primarily because of the horizontal thermal conductivity along the pad's medium. I'm hoping for this 3800x chip, it will do the same. Meaning, the idea being that there wont be a hot-spot generated, it will just cover the entire heat spreader.

 

In the mean time, I still value anyone else's input. If you've got data, please continue posting. I'll also provide an update once the pad arrives in mail. 

[StDragon]

Update: So just installed the IC Graphite pad. The temperature range between idle and full load with Prime95 (same settings as before) is about the same 38c - 87c. But this time when I stop Prime 95, the temps drop all the way from high to low in seconds! Clearly the graphite pad is doing its job at thermal transfer. 

 

Given this is the worst case scenario, I'm pretty happy with the results so far. I'm convinced It's as good as it gets with air cooling. 

 

Unless others with more AMD experience can chime in, I'm thinking the limit here is just the chip.