AMD or Intel for sff gaming build thermals?

Trying to find the best CPU for a sff gaming build with limited thermal headroom. I want it as cool and quiet as possible and don't plan to overclock. I am also only interested in 4k60fps. I know I can get by with a low end 4-core CPU and still have performance to spare, but a high clocked 4-core CPU probably uses more power and produces more heat than a low clock 8-core CPU, depending on how well multi-threaded the game is. There's also the IPC difference between AMD and Intel. Basically asking, with perrformance being equal (enough to hit 4k60fps in most games), which CPU should I get that produces the least amount of heat?

silverwolf0 said:

Trying to find the best CPU for a sff gaming build with limited thermal headroom. I want it as cool and quiet as possible and don't plan to overclock. I am also only interested in 4k60fps. I know I can get by with a low end 4-core CPU and still have performance to spare, but a high clocked 4-core CPU probably uses more power and produces more heat than a low clock 8-core CPU, depending on how well multi-threaded the game is. There's also the IPC difference between AMD and Intel. Basically asking, with perrformance being equal (enough to hit 4k60fps in most games), which CPU should I get that produces the least amount of heat?

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I went r7 1700 + noctua nh l9a for my sff build. It stayed under 70C even in all core combined cpu/gpu loads. The gpu (1050ti) is tougher to keep cool, I ended up putting a larger 120mm fan on the noctua hsf to get more cool air to the video card (and rest of the system). I'm in a similar place as you given I have a sub 5L build with 200w psu, so that was the maximum I could get in terms of computing power for that power budget. Keeping everything cool is just a matter of tuning the fan curve - and that's more to cool the rest of the build than to keep the cpu cool. It only hits 62Cmax but I have to run the fan higher than necessary for the cpu to keep the gpu below 84C (which is the throttle point).

I think TDP on both CPUs (Skylake vs Zen+) is going to be similar - +/- 10% or so.

There is a good case to make against Intel 9000 series - they changed "default" power management to allow significantly going over TDP (or rather, they changed their definition of TDP to be meaningless). Now, if you were going to overclock, you'd be doing that anyway, and you can disable it... but it's still something to consider if you don't like monkeying around with BIOS settings too much.

But, a good point in Intel's favor - with similar TDP, the more important issue becomes "race to idle" - meaning all other things equal the fastest IPC is going to use the least total power.

Heatsink and case are going to determine your ultimate temps that you get, but you aren't going to change the physics of it, and lower total power consumption will mean less thermal energy that needs to be remove.

Would be good to see some power draw numbers -- I'm sure they exist I just don't have them handy. I would guess Intel would still win here (any of the Skylake family, which is anything from 6000 to 9000 series), provided you cap your power draw on a 9000 series to keep from overrunning a SFF thermal installation.

Another point to make as well - CPU is a big heat load, but GPU can easily become 2-3X the total thermal energy of the CPU, and will make a much larger difference.

Lots of good info above. One thing I'd like to point out is to make sure you pay for good cooling on the gpu. A lot of lesser cards spec wise have subpar cooling. Even with lower power draws they are still very loud under load. My experience.

I doubt a low end quad core will push a high enough gfx cards to 4k60, you're going to need to be in the higher end of the spectrum, either with an intel 6 core, or AMD 6/8 core

I'd go with either an R7 2700 (non-X) or a i7-8700 (non-k). Both are 65W processors that should give you the most bang for the buck within the thermal limits I would think.

kirbyrj said:

I'd go with either an R7 2700 (non-X) or a i7-8700 (non-k). Both are 65W processors that should give you the most bang for the buck within the thermal limits I would think.

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Wouldn't the X be better than non-x, just let XFR2 and Boost do their thing

It is all dependent on your case and what kind of cooling you have access too.

With something a bit bigger like a NCASE M1 or Louqe Ghost S1, you could fit a 240mm radiator for the CPU (9900k capable) and then get yourself a solid 2080ti and probably make it work.

Ambient temperatures will always be a challenge with components that have high heat generation. I think it is doable though.

Digital Viper-X- said:

Wouldn't the X be better than non-x, just let XFR2 and Boost do their thing

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Not sure in a purely gaming build. If there was any sustained encoding or anything that would load up the processor over time the 65W TDP would help. But to push 4k60 he's going to need a beefy video card that's going to throw off the thermals anyway. What's a little extra heat when you're running a 250W video card.

Digital Viper-X- said:

Wouldn't the X be better than non-x, just let XFR2 and Boost do their thing

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Only if the motherboard allows setting tdp lower - the x are 95w by default but some motherboards allow setting tdp lower. This gives similar boost curve until you go over 6 core loads and then clocks tail off slightly, so for most loads yields a faster system without more peak draw.