Time for a new computer - what processor?

[macboy]

The Threadrippers are not *that* expensive.

Nope.  Certainly a valid way of getting 4-channel performance. 

The Intel 4-channel "desktop" chips are certainly not cheap! 

Also, the "entry level" Intel CPUs that use LGA2066 only have dual-channel memory support.

If you need 4-channel on the cheap, it might be a better idea to use second hand Intel LGA2011 based systems. Those were decommissioned en masse a few years ago and cleap LGA2011 (not the -1 or -3 variety) ans matching DDR3 memory flooded the market.

THIS
I have a workstation built from two E5-2690 XEONs, which are 8 cores (16 threads) each, and have quad channel memory (each) at 1866 MHz, using dirt cheap registered ECC DDR3 (I paid $3/GB). The memory bandwidth per CPU is nearly 60 GB/s, and the CPUs have 20 MB of L3 cache each. Yes, the pure MHz speed is slower than the fastest DDR4, but more channels does make up the difference.  The CPUs are 2.9 GHz nominal, but run at 3.3 GHz continuously with all cores loaded or up to 3.8 GHz one core loaded, which is right on par with modern typical high performance desktop CPUs. It is very impressive compute power for the money. Power draw of the system is rather high under full load, but well under 100 W at idle (including several HDDs).  The power consumption per performance is the biggest drawback of these older CPUs, and that is the main reason that these otherwise fast and viable server CPUs are cheap and plentiful on the 2nd hand market. For a server farm under constant high load, the energy cost outweighs cost of more efficient newer hardware. For a home system which is lightly loaded most of the time, but needs the performance on occassion, these older CPUs are a fantastic bargain. You are unlikely to spend as much on extra energy vs. extra cost for newer more efficient hardware of equal performance.

[Simon]

Considering how long I "hope" this machine will last I will take the modern hardware with lower power consumption.

[drussell]

Considering how long I "hope" this machine will last I will take the modern hardware with lower power consumption.

Indeed.  I'm seriously considering starting to replace more of my old hardware that is doing server duty with Ryzen setups just for the power savings.  (Especially if I can find a good supply of some reasonably priced unbuffered ECC DDR4.)  Even with our power cost usually down in the 3-6 cent per kWh my monthly power for the servers here is over $200 / mo, and if power spikes up to 10-12+ cents that's a significant chunk of change, even just for a month or two long spike in the rate.  (I just pay the market rate and take my chances...    Overall it is cheaper than power plan options in the long run with an essentially fixed load.)

The power consumption at idle of the last desktop Ryzen setup I tested it on (I think that was one of the 2400Gs with a single SSD and a DVD burner, using only internal GPU and a good PSU) was only a few watts.  Not even worth trying to set the thing to use the "sleep" modes to save power.  The fans stop spinning at idle anyway and the CPU is so power efficient at idle that it's just not necessary, they throttle themselves down to virtually nothing anyway. 

I actually had problems with the first 2400G system I built since it ran FreeBSD.  While you would never notice it if it were a Windows box since it would never get that idle, it would crash if you left it idle for long enough, like overnight at a prompt after recompiling the whole OS, it would just be frozen in the morning because the PSU didn't keep the power clean enough at no load.  ASUS actually had to add an option in the BIOS to tell it to NOT go into the deepest powersave state to intentionally make it draw more juice.  If they hadn't added that option (I had pre-ordered that first 2400G before they even went on sale) by the time I wanted to deliver it to a customer I would have had to leave a resistor rigged up in there just to burn a couple extra watts of power all the time.

What a change in efficiency compared to traditional setups!!

Simon, I think you'll be pleased with your setup and it will probably pay for itself anyway vs. a used server chip.  Excellent for machines anyone wants to leave on all the time, for sure!

[Mr. Scram]

Considering how long I "hope" this machine will last I will take the modern hardware with lower power consumption.

The increase in processor power may not have been very impressive in recent years, but efficiency has definitely been improved quite a bit. Especially the powering down of unused subsystems has massively changed the past half decade or so.

[drussell]

The increase in processor power may not have been very impressive in recent years, but efficiency has definitely been improved quite a bit. Especially the powering down of unused subsystems has massively changed the past half decade or so.

For sure!  These latest generation desktop chips have all the computing power you expect in a high performance CPU with the typical power consumption more traditionally associated with mobile-only platforms.