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TDP matters a fair bit in SFF(Small Form Factor) PCs. For instance the 3700x is a fantastic little CPU since it has a 65W TDP but pretty solid performance. In

TDP matters a fair bit in SFF(Small Form Factor) PCs. For instance the 3700x is a fantastic little CPU since it has a 65W TDP but pretty solid performance. In a sandwich style case you're usually limited to low profile coolers like Noctua L9i/L9a since vertical height is pretty limited.

phkahler 6y ago
I'm running a 2400G in a Mellori-ITX. Another issue is sizing the power supply.
mlyle 6y ago
Performance/watt matters. You can just set TDP to what you want with throttling choices. If you want a 45W TDP from the 3700X, you can just pop into Ryzen Master and ask for a 45W TDP. Boom, you're running in that envelope. I think shopping based on TDP is not the best, because it's not comparable between manufacturers and because it's something you can effectively "choose".
- vvanders 6y ago
  Yeah but can I get a metric ton of benchmarks at that 45w setpoint? I don't really see the reason in paying for a 100w TDP premium if I'm just going to scale it down to 65w.
  - mlyle 6y ago
    > Yeah but can I get a metric ton of benchmarks at that 45w setpoint? Yup, they're out there. > I don't really see the reason in paying for a 100w TDP premium if I'm just going to scale it down to 65w. You might want the core count or peak performance for the very short term. When I was looking, running 65W parts in the 45W envelope was only about a 7% penalty, so you get a bunch more performance/watt.
- mongol 6y ago
  How do you do that? Is it a setting in the bios? Or can it be done runtime? If so, how? It sounds interesting if I can run a beefy rig as a power efficient device, for always-on scenarios, and then boost it when I need.
  - mlyle 6y ago
    > How do you do that? Is it a setting in the bios? Or can it be done runtime? On AMD, it's a utility you run. I believe you may require a reboot to apply it. On some Intel platforms, it's been settings in the BIOS. > It sounds interesting if I can run a beefy rig as a power efficient device, for always-on scenarios, and then boost it when I need. This is what the processor is doing internally anyways. It throttles voltage and frequency and gates cores based on demanded usage. Changing the TDP doesn't change the performance under a light-to-moderate workload scenario at all. Ryzen Master lets you change some of the tuning for the choices it makes about when and how aggressively to boost, though, too.
    - Cloudef 6y ago
      Ryzen Master doesnt seem to be available for linux so you end up with bunch of unnofficial hacks that may or may not work. I run sff setup myself, originally wanted to get 3600 but it was out of stock, and the next tdp friendly processor was 3700x.
      - mlyle 6y ago
        That's an annoyance, but on Linux you have infinite more control of thermal throttling and you can get whatever thermal behavior you want. Thermald has been really good on Intel, and now that Google contributed RAPL support you can get the same benefits on AMD-- pick exactly your power envelope and thermal limits.

phkahler 6y ago

I'm running a 2400G in a Mellori-ITX. Another issue is sizing the power supply.

mlyle 6y ago

Performance/watt matters. You can just set TDP to what you want with throttling choices. If you want a 45W TDP from the 3700X, you can just pop into Ryzen Master and ask for a 45W TDP. Boom, you're running in that envelope. I think shopping based on TDP is not the best, because it's not comparable between manufacturers and because it's something you can effectively "choose".

vvanders 6y ago
Yeah but can I get a metric ton of benchmarks at that 45w setpoint? I don't really see the reason in paying for a 100w TDP premium if I'm just going to scale it down to 65w.
- mlyle 6y ago
  > Yeah but can I get a metric ton of benchmarks at that 45w setpoint? Yup, they're out there. > I don't really see the reason in paying for a 100w TDP premium if I'm just going to scale it down to 65w. You might want the core count or peak performance for the very short term. When I was looking, running 65W parts in the 45W envelope was only about a 7% penalty, so you get a bunch more performance/watt.
mongol 6y ago
How do you do that? Is it a setting in the bios? Or can it be done runtime? If so, how? It sounds interesting if I can run a beefy rig as a power efficient device, for always-on scenarios, and then boost it when I need.
- mlyle 6y ago
  > How do you do that? Is it a setting in the bios? Or can it be done runtime? On AMD, it's a utility you run. I believe you may require a reboot to apply it. On some Intel platforms, it's been settings in the BIOS. > It sounds interesting if I can run a beefy rig as a power efficient device, for always-on scenarios, and then boost it when I need. This is what the processor is doing internally anyways. It throttles voltage and frequency and gates cores based on demanded usage. Changing the TDP doesn't change the performance under a light-to-moderate workload scenario at all. Ryzen Master lets you change some of the tuning for the choices it makes about when and how aggressively to boost, though, too.
  - Cloudef 6y ago
    Ryzen Master doesnt seem to be available for linux so you end up with bunch of unnofficial hacks that may or may not work. I run sff setup myself, originally wanted to get 3600 but it was out of stock, and the next tdp friendly processor was 3700x.
    - mlyle 6y ago
      That's an annoyance, but on Linux you have infinite more control of thermal throttling and you can get whatever thermal behavior you want. Thermald has been really good on Intel, and now that Google contributed RAPL support you can get the same benefits on AMD-- pick exactly your power envelope and thermal limits.