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pramodsenevi
Journeyman III

How can I lower TDP of my Ryzen 2400G?

Please provide me the ansers to how AMD Ryzen configurable TDP can be adjusted. I'am using a ASUS PRIME X370-PRO Mainboard. Thank You!

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7 Replies
misterj
Exemplar

Re: How can I lower TDP of my Ryzen 2400G?

pramodsenevi, I do not understand!  TDP (Total Dissipated Power) is a specification for the processor and a user cannot change it.  If you want to reduce the power usage then use Ryzen Master (RM) to reduce the CPU clock and voltage.  Enjoy, John.

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john_m
Adept I

Re: How can I lower TDP of my Ryzen 2400G?

Actually, TDP means Thermal Design Power, which these days has little to do with the amount of electrical energy used or the heat dissipated (which, of course, are necessarily identical) by the processor. It's used more as a guide for choosing an appropriate cooling solution - processor A is in this class, so needs this amount of cooling. Different manufacturers use different methods of calculating TDP and modern CPUs when under load can dissipate considerably more than the rated TDP. The situation of an APU, such as the OP's Ryzen 5 2400G is even more complicated because, not only does it contain four Zen cores, but a powerful integrated Vega GPU. Getting the power balance correct is quite a complex process for the internal control circuits. Running a heavily threaded CPU benchmark can make the processor exceed it's rated 65 watts by a considerable margin, as can running an intensive GPU benchmark. Running both together would push the power consumption well over 100 watts if the control circuit didn't intervene and reduce the clock frequencies of both GPU and cores.

The Ryzen 5 2400G is specifically advertised as having a configurable TDP of 46 to 65 watts so the OP's question is far from unreasonable. There is no way that I can see for the setting to be adjusted in Ryzen Master. I would expect the setting to be made somewhere in the motherboard BIOS. Hopefully with a bit of digging it will become obvious. I'm sorry, but I have no experience of the motherboard the OP mentions.

I have a similar problem, though. I have a very slim mini-ITX build that has limited options for cooling so I chose the low power 35 watt TDP variant, the Ryzen 5 2400GE. Under a heavy OpenCL load it dissipates around 50 watts with the cores idling and the GPU running flat out. With the case open I measure Tdie at around 65 degrees C. With the case closed the fan increases to maximum speed but the hot air is trapped and Tdie increases to around 85 degrees C. If I rest the GPU and stress the CPU cores with eight threads it dissipates more than 80 watts, with one of the cores running at the full boost frequency of 3.8 GHz and the other three only a little behind, which is wonderful - I think I've got a great chip, if only I could keep it cool I could get some great work out of it. With the case open Tdie reaches 78 degrees C. With the case closed the fan ramps up to maximum speed but the trapped hot air causes Tdie to exceed the 95 degree C maximum, which results in thermal throttling as the CPU reduces the clock frequencies to protect itself. That's fine but eventually the case gets too hot to touch and I don't like the idea of other components, such as the RAM and the M.2 SSD getting that hot. What I would like to have is the ability to enforce a stricter limit on the power dissipated than the default. A hard limit of, say, 45 to 50 watts for my 2400GE would be ideal.

I have experimented with Ryzen Master and I can sucessfully underclock the CPU cores. I have tried to underclock the GPU too, but the setting of, say, 800 MHz doesn't stick and it always runs up to 1240 MHz. I have had some success from creating a new Windows power profile and setting the maximum CPU speed to 75%, which is very effective in limiting the core clocks to 2.3 GHz. But none of these options is ideal. What I want is for the CPU to control it own operating parameters, just as it does with stock settings, but within a more restricted power budget. My motherboard (an Onda B320-IPC) has a very primitive BIOS compared with the more mainstream offerings from the likes of Gigabyte and Asus and so far I have not found any TDP control options. It does, however, give full access to the somewhat arcane AMD CBS menus so maybe I'll find something appropriate there?

john_m
Adept I

Re: How can I lower TDP of my Ryzen 2400G?

After doing some research following my comment above I offer the following as a possible answer to the original question.

In the BIOS setup select the Advanced tab.

Choose AMD CBS.

Choose NBIO Common Options.

Choose System Configuration.

A menu should appear with the following options: Auto, 35W, 45W, 65W.

The default is Auto. I don't expect all options to work for all processors but for the OP's 2400G at least the 65W and 45W options ought to work. Make your selection and choose the Save and Exit option to quit BIOS setup and boot the OS.

Another related menu item might be of interest.

In the BIOS setup select the Advanced tab.

Choose AMD CBS.

Choose Zen Common Options.

Choose Core Performance Boost.

A menu should appear with the following options: Auto, Disabled.

The default is Auto. You might want to try selecting Disabled then choose the Save and Exit option to quit BIOS setup and boot the OS.

In my particular case (see above), the first menu item doesn't help as my 2400GE is already running with a nominal 35 watt TDP. The second menu item is rather like the custom low power Windows power profile I mentioned above, which works but I find too restrictive as I want my processor to boost opportunistically - I'd just like to have more control over the power envelope. In the end I decided to find a different case with better ventilation for my system. So I moved it out of the generic slim case I bought from Alibaba and into a Silverstone PT13, which has considerably bigger ventilation holes. Unfortunately the PCCooler heatsink and fan that just managed to fit inside the old case is a couple of millimetres too tall for the new case so I had to buy a Silverstone NT07-115X, which is the only cooler I know of that definitely fits inside the case. Yes, it's an Intel-style cooler but that's what my Onda AM4 motherboard needs. The copper slug inside the heatsink has a round profile which only makes contact with the central portion of the CPU's heat spreader but it does the job. My initial tests are encouraging.

sgtkalash
Adept I

Re: How can I lower TDP of my Ryzen 2400G?

Hello John. could please help me with the Ryzen Master app, I would like to know if there is a tutorial out there on how to use it or if you could explain to me, I never done overclocking or underclocking and I would like to learn. 

My specs:

r9 3900x

1070ti

gigabyte x570 elite

evo 970 plus 500gb

hyperx predator 16gb DDR4 3200

Thanks

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nickjackalson
Adept III

Re: How can I lower TDP of my Ryzen 2400G?

easy, disable core boost, and/or disable SMT in regards of your workload

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john_m
Adept I

Re: How can I lower TDP of my Ryzen 2400G?

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john_m
Adept I

Re: How can I lower TDP of my Ryzen 2400G?

I did consider disabling SMT but it seems rather brutal, given that I spent the extra money on the eight-thread 2400GE instead of the four-thread 2200GE.

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