5 ms·

Intel's is roughly "the thermal dissipation required to maintain base clock speeds indefinitely without thermal throttling". AMD's is roughly "the thermal diss

Intel's is roughly "the thermal dissipation required to maintain base clock speeds indefinitely without thermal throttling". AMD's is roughly "the thermal dissipation required for all-core turbo indefinitely". In recent generations (since AMD's Zen architecture), AMD is much closer in testing to their published numbers than Intel is. It is important to note that this is a thermal specification, rather than a power consumption specification. There are processors that exist which can hit their performance numbers without needing any thermal solution, and as such would have an "honest" TDP of 0, despite having a >0 power draw from the wall.

abryzak 7y ago
Gamers Nexus has a video & article explaining how TDP is primarily a marketing term. https://www.gamersnexus.net/guides/3525-amd-ryzen-tdp-explained-deep-dive-cooler-manufacturer-opinions https://www.gamersnexus.net/guides/3525-amd-ryzen-tdp-explai...
wahern 7y ago
I really wish they'd publish the range. Last year I built an AMD EPYC 3201 (embedded) with a 30W TDP (replacing a Xeon E3-1220v3[1]). Because it sits idle or under very low load most of the time, and though my power is effectively free (under my office lease I pay a fixed share of building utilities based on my square footage), I don't want to unnecessarily waste energy, generate a ton of heat (130-year-old building, A/C is adjusted by window height), or go deaf from the fans. Also, I prefer short depth rack mount cases which means everything is stuffed in there tight.[2] It idles at about ~20W and maxes ~45W (+/- 5W, I forget) as measured at the outlet, but if a more powerful CPU idled at 30W and only peaked to 100-150W at full load, I'd prefer that (especially for a future replacement for my VM host), as the 1% of time I need the performance it's definitely worth it. But it's hard to find reliable numbers, if any numbers at all other than the marketing TDP, so I just err on the safe side. [1] The older E3s were amazing, at least in the pre-Meltdown, pre-Spectre era. I built 2 E3-1220v2 boxes and 2 E3-1220v3 boxes, and at full load (all cores at max, with or without heavy memory transfer) both drew under their published TDPs at the outlet. [2] Supermicro's EPYC embedded motherboard is a poor fit for the officially paired short depth case, especially the power connector. The case was originally designed for their Atom, Xeon E3, and Xeon D boards. With their EPYC embedded board the power connector needs an adapter, and the adapter and wires have to be stuffed forcefully in an awkward and worrisome manner, much more awkward than is typical for a poorly designed configuration. I think I spent a day confirming that I wasn't doing something wrong, and than another day looking in vein for an alternative adapter that wasn't so large. But I really wanted the EPYC to replace the E3, and didn't want to wait any longer. And it seems I'd still be waiting if I had. For all its flaws Supermicro's solution still seems the most practical for stuffing an AMD Zen CPU into a short depth rackmount case, whether EPYC or Ryzen.
aftbit 7y ago
>There are processors that exist which can hit their performance numbers without needing any thermal solution, and as such would have an "honest" TDP of 0, despite having a >0 power draw from the wall. Nitpick warning - I assume you mean that they are passively cooled in free air. They are still emitting heat into their environment. If you stuck such a processor into a perfectly insulated container, it would eventually overheat and throttle down. So it's really only fair to call them 0 TDP if you ignore the base "free" cooling. You could make the same assumption about power if you just stuck a solar panel on top (like a calculator processor) and then ignored that power input.
- deleted 7y ago
  [deleted]
- greggyb 7y ago
  This is correct.

abryzak 7y ago

Gamers Nexus has a video & article explaining how TDP is primarily a marketing term. https://www.gamersnexus.net/guides/3525-amd-ryzen-tdp-explained-deep-dive-cooler-manufacturer-opinions https://www.gamersnexus.net/guides/3525-amd-ryzen-tdp-explai...

wahern 7y ago

I really wish they'd publish the range. Last year I built an AMD EPYC 3201 (embedded) with a 30W TDP (replacing a Xeon E3-1220v3[1]). Because it sits idle or under very low load most of the time, and though my power is effectively free (under my office lease I pay a fixed share of building utilities based on my square footage), I don't want to unnecessarily waste energy, generate a ton of heat (130-year-old building, A/C is adjusted by window height), or go deaf from the fans. Also, I prefer short depth rack mount cases which means everything is stuffed in there tight.[2] It idles at about ~20W and maxes ~45W (+/- 5W, I forget) as measured at the outlet, but if a more powerful CPU idled at 30W and only peaked to 100-150W at full load, I'd prefer that (especially for a future replacement for my VM host), as the 1% of time I need the performance it's definitely worth it. But it's hard to find reliable numbers, if any numbers at all other than the marketing TDP, so I just err on the safe side. [1] The older E3s were amazing, at least in the pre-Meltdown, pre-Spectre era. I built 2 E3-1220v2 boxes and 2 E3-1220v3 boxes, and at full load (all cores at max, with or without heavy memory transfer) both drew under their published TDPs at the outlet. [2] Supermicro's EPYC embedded motherboard is a poor fit for the officially paired short depth case, especially the power connector. The case was originally designed for their Atom, Xeon E3, and Xeon D boards. With their EPYC embedded board the power connector needs an adapter, and the adapter and wires have to be stuffed forcefully in an awkward and worrisome manner, much more awkward than is typical for a poorly designed configuration. I think I spent a day confirming that I wasn't doing something wrong, and than another day looking in vein for an alternative adapter that wasn't so large. But I really wanted the EPYC to replace the E3, and didn't want to wait any longer. And it seems I'd still be waiting if I had. For all its flaws Supermicro's solution still seems the most practical for stuffing an AMD Zen CPU into a short depth rackmount case, whether EPYC or Ryzen.

aftbit 7y ago

>There are processors that exist which can hit their performance numbers without needing any thermal solution, and as such would have an "honest" TDP of 0, despite having a >0 power draw from the wall. Nitpick warning - I assume you mean that they are passively cooled in free air. They are still emitting heat into their environment. If you stuck such a processor into a perfectly insulated container, it would eventually overheat and throttle down. So it's really only fair to call them 0 TDP if you ignore the base "free" cooling. You could make the same assumption about power if you just stuck a solar panel on top (like a calculator processor) and then ignored that power input.

deleted 7y ago
[deleted]
greggyb 7y ago
This is correct.