5 ms·

> but even low-end Ryzen Threadripper CPUs have TDP of 180W, which is a bit higher than I'd like. Why does it matter? It doesn't idle that high; it only goes t

> but even low-end Ryzen Threadripper CPUs have TDP of 180W, which is a bit higher than I'd like. Why does it matter? It doesn't idle that high; it only goes that high of you're using it flat out, in which case the extra power usage is justified because it's giving that much more performance over a 100 W TDP CPU. Now I totally get it if you don't want to go Threadripper just for ECC because it's more expensive, but max power draw, which you don't even have to use? I've never seen anyone shop a desktop CPU by TDP, rather than by performance and price.

ClumsyPilot 6y ago
If the concern is about heat and noise, the cooling system is the most important factor, oddly I don't see it even mentioned. Get a huge cooler like Noctua d14, and you pc becomes silent. It lasts forever, requires no maintenance, a good investment. If you are adventurous, watercooling is even better, but its a can of worms I decided I'd rather live without - possibility of leaks and cost make it harder to justify
defanor 6y ago
I prefer to pick PSU and fans (for both CPU and chassis) that can handle it comfortably (preferably while staying silent and with some reserve) with maximum TDP in mind, and given that I don't need that many cores or high clock speed either, a powerful CPU with high TDP is undesirable because it just makes picking other parts harder. I've mentioned TDP explicitly because I wouldn't mind if it was a (possibly even high-end) Threadripper that somehow didn't produce as much heat. Although price also matters, indeed.
phkahler 6y ago
>> I've never seen anyone shop a desktop CPU by TDP, rather than by performance and price. Oh oh, me! Back in the day I bought a 65W CPU for a system that could handle a 90W. I wanted quiet and figured that would keep fan noise down at a modest performance penalty. It should also last longer, being the same design but running cooler. I ran that from 2005 until a few years ago (it still run fine but is in storage). Planning to continue this strategy. I suspect it's common among SFF enthusiasts.
- koolba 6y ago
  SFF?
  - lostlogin 6y ago
    The Intel Nuc and Mac mini are good examples of this - however the Nuc doesn’t have its psu inside, it’s a brick. Great for fixing failures, horrible in general as a built in psu is so much tidier.
    - srtjstjsj 6y ago
      Internal PSU adds heat that is noisy or expensive to dissipate or is avoided by throttling performance.
  - oconnor663 6y ago
    "small form factor" as far as I can tell
- sam_lowry_ 6y ago
  Hm... My 2013 NUC in fanless Akasa enclosure runs 24/7 on a 6W CPU, I recently looked at the options, and the 2019 6W offering changes little in performance. Yes, memory got faster, but that's it. My passive-cooled desktop is also running a slightly trottled down 65W CPU. So yes, there are people who choose there hardware by TDP.
  - francis-io 6y ago
    When looking for a CPU for a server that sits in my living room, I went down the thought process of getting a low tdp. I don't have a quote, but I seem to remember coming to the conclusion that tdp is the max temp threshold, not the consistent power draw. If you have a computer idling I believe you won't see a difference in temp between cpus, but you will have the performance when you need it. These days, a quiet, pwm fan with good thermal paste (and maybe some linux CPU throttling) more than achieves my needs for a "silent" pc 99% of the time. I would love to be told my above assumptions are wrong if they are.
bayindirh 6y ago
> I've never seen anyone shop a desktop CPU by TDP, rather than by performance and price. That's me. When I start to plan for a new system, I select the processor first and read its thermal design guidelines (Intel used to have nice load vs. max temp graphs in their docs) and select every component around it for sustained max load. This results in a more silent system for idle and peace of mind for loading it for extended duration.
- 411111111111111 6y ago
  That's not necessarily correct. You can passively cool threadrippers if you underclock them enough and have good ventilation in case.
  - bayindirh 6y ago
    If my only interest would be ECC, I might do that but, I develop scientific software for research purposes. I need every bit of performance from my system. In my case loading means maxing out all cores and extended period of time can be anything from five minutes to hours.
    - mlyle 6y ago
      The problem is-- you can't compare the TDP nor even the system cooling design guidelines between AMD and Intel. Both are optimistic lies, but-- if you look at the documents it looks like currently AMD needs more cooling, but actually dissipates less power in most cases and definitely has higher performance/watt.
      - bayindirh 6y ago
        > The problem is-- you can't compare the TDP nor even the system cooling design guidelines between AMD and Intel. Doesn't matter for me since I'm not interested in comparing them. > Both are optimistic lies, but-- if you look at the documents it looks like currently AMD needs more cooling, but actually dissipates less power in most cases and definitely has higher performance/watt. I'm aware of the situation, and I always inflate the numbers 10-15% to increase headroom in my systems. The code I'm running is not a most case code. A FPU heavy, "I will abuse all your cores and memory bandwidth" type, heavily optimized scientific software. I can sometimes hear that my system is swearing at me for repeatedly running for tests. I don't like to add this paragraph but, I'm one of the administrators of one of the biggest HPC clusters in my country. I know how a system can surpass its TDP or how can CPU manufacturers skew this TDP numbers to fit in envelopes. We make these servers blow flames from their exhausts.

ClumsyPilot 6y ago

If the concern is about heat and noise, the cooling system is the most important factor, oddly I don't see it even mentioned. Get a huge cooler like Noctua d14, and you pc becomes silent. It lasts forever, requires no maintenance, a good investment. If you are adventurous, watercooling is even better, but its a can of worms I decided I'd rather live without - possibility of leaks and cost make it harder to justify

defanor 6y ago

I prefer to pick PSU and fans (for both CPU and chassis) that can handle it comfortably (preferably while staying silent and with some reserve) with maximum TDP in mind, and given that I don't need that many cores or high clock speed either, a powerful CPU with high TDP is undesirable because it just makes picking other parts harder. I've mentioned TDP explicitly because I wouldn't mind if it was a (possibly even high-end) Threadripper that somehow didn't produce as much heat. Although price also matters, indeed.

phkahler 6y ago

>> I've never seen anyone shop a desktop CPU by TDP, rather than by performance and price. Oh oh, me! Back in the day I bought a 65W CPU for a system that could handle a 90W. I wanted quiet and figured that would keep fan noise down at a modest performance penalty. It should also last longer, being the same design but running cooler. I ran that from 2005 until a few years ago (it still run fine but is in storage). Planning to continue this strategy. I suspect it's common among SFF enthusiasts.

koolba 6y ago
SFF?
- lostlogin 6y ago
  The Intel Nuc and Mac mini are good examples of this - however the Nuc doesn’t have its psu inside, it’s a brick. Great for fixing failures, horrible in general as a built in psu is so much tidier.
  - srtjstjsj 6y ago
    Internal PSU adds heat that is noisy or expensive to dissipate or is avoided by throttling performance.
- oconnor663 6y ago
  "small form factor" as far as I can tell
sam_lowry_ 6y ago
Hm... My 2013 NUC in fanless Akasa enclosure runs 24/7 on a 6W CPU, I recently looked at the options, and the 2019 6W offering changes little in performance. Yes, memory got faster, but that's it. My passive-cooled desktop is also running a slightly trottled down 65W CPU. So yes, there are people who choose there hardware by TDP.
- francis-io 6y ago
  When looking for a CPU for a server that sits in my living room, I went down the thought process of getting a low tdp. I don't have a quote, but I seem to remember coming to the conclusion that tdp is the max temp threshold, not the consistent power draw. If you have a computer idling I believe you won't see a difference in temp between cpus, but you will have the performance when you need it. These days, a quiet, pwm fan with good thermal paste (and maybe some linux CPU throttling) more than achieves my needs for a "silent" pc 99% of the time. I would love to be told my above assumptions are wrong if they are.

bayindirh 6y ago

> I've never seen anyone shop a desktop CPU by TDP, rather than by performance and price. That's me. When I start to plan for a new system, I select the processor first and read its thermal design guidelines (Intel used to have nice load vs. max temp graphs in their docs) and select every component around it for sustained max load. This results in a more silent system for idle and peace of mind for loading it for extended duration.

411111111111111 6y ago
That's not necessarily correct. You can passively cool threadrippers if you underclock them enough and have good ventilation in case.
- bayindirh 6y ago
  If my only interest would be ECC, I might do that but, I develop scientific software for research purposes. I need every bit of performance from my system. In my case loading means maxing out all cores and extended period of time can be anything from five minutes to hours.
  - mlyle 6y ago
    The problem is-- you can't compare the TDP nor even the system cooling design guidelines between AMD and Intel. Both are optimistic lies, but-- if you look at the documents it looks like currently AMD needs more cooling, but actually dissipates less power in most cases and definitely has higher performance/watt.
    - bayindirh 6y ago
      > The problem is-- you can't compare the TDP nor even the system cooling design guidelines between AMD and Intel. Doesn't matter for me since I'm not interested in comparing them. > Both are optimistic lies, but-- if you look at the documents it looks like currently AMD needs more cooling, but actually dissipates less power in most cases and definitely has higher performance/watt. I'm aware of the situation, and I always inflate the numbers 10-15% to increase headroom in my systems. The code I'm running is not a most case code. A FPU heavy, "I will abuse all your cores and memory bandwidth" type, heavily optimized scientific software. I can sometimes hear that my system is swearing at me for repeatedly running for tests. I don't like to add this paragraph but, I'm one of the administrators of one of the biggest HPC clusters in my country. I know how a system can surpass its TDP or how can CPU manufacturers skew this TDP numbers to fit in envelopes. We make these servers blow flames from their exhausts.