128-core AMD server

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Leo
Posts: 428
Joined: Fri Sep 16, 2016 4:55 pm
Location: Saint Paul, Minnesota USA

Re: 128-core AMD server

Post by Leo » Sat Nov 25, 2017 8:56 pm

jdart wrote:Some benchmarks (Stockfish 8, 16G hash):

32-core dual Opteron (2xOpteron 6376, 1/4 of the AMD server box, Linux):
26.3M nps

24-core dual Opteron (2xOpteron 6344, Linux):
21.8M nps

dual Xeon 2670 (16 cores, Linux):
24.0M nps

i7-6900k (8 cores, Windows):
14.08M nps
What about the argument that its time to depth that matters?
Brainfish fan. AMD fan.

Leo
Posts: 428
Joined: Fri Sep 16, 2016 4:55 pm
Location: Saint Paul, Minnesota USA

Re: 128-core AMD server

Post by Leo » Sat Nov 25, 2017 8:59 pm

jdart wrote:Rates in my area ramp up with usage and I have once in a while hit their "super overcharge now we're really serious" rate level, whatever they actually call it.

I am planning to get solar panels on the house next year.

--Jon
I have a 15 amp breaker that kept tripping. It was hot to the touch. I now have to wait until I can hook up the computer to 20 amps.
Brainfish fan. AMD fan.

jhellis3
Posts: 340
Joined: Fri Aug 16, 2013 10:36 pm

Re: 128-core AMD server

Post by jhellis3 » Sat Nov 25, 2017 9:20 pm

What about the argument that its time to depth that matters?
TTD is a useless measurement for LazySMP.

Adam Hair
Posts: 3183
Joined: Wed May 06, 2009 8:31 pm
Location: Fuquay-Varina, North Carolina

Re: 128-core AMD server

Post by Adam Hair » Sat Nov 25, 2017 11:12 pm

Leo wrote:
jdart wrote:Rates in my area ramp up with usage and I have once in a while hit their "super overcharge now we're really serious" rate level, whatever they actually call it.

I am planning to get solar panels on the house next year.

--Jon
I have a 15 amp breaker that kept tripping. It was hot to the touch. I now have to wait until I can hook up the computer to 20 amps.
Have your electrician check for a loose connection also. There could be a problem where the wire connects to the circuit breaker (small possibility) or where the circuit breaker plugs onto the electrical panel busbar (greater possibility). It is doubtful that you have a large enough overcurrent to cause the circuit breaker to be hot to the touch.

My guess is that the connection between the breaker and busbar is failing.

Leo
Posts: 428
Joined: Fri Sep 16, 2016 4:55 pm
Location: Saint Paul, Minnesota USA

Re: 128-core AMD server

Post by Leo » Sun Nov 26, 2017 12:48 am

I have read over and over that a powerful 8-16 core machine will defeat a 32-64 core machine. After 16 to 20 cores it scales very badly. Has something changed or is this still true?
Brainfish fan. AMD fan.

Leo
Posts: 428
Joined: Fri Sep 16, 2016 4:55 pm
Location: Saint Paul, Minnesota USA

Re: 128-core AMD server

Post by Leo » Sun Nov 26, 2017 12:50 am

Adam Hair wrote:
Leo wrote:
jdart wrote:Rates in my area ramp up with usage and I have once in a while hit their "super overcharge now we're really serious" rate level, whatever they actually call it.

I am planning to get solar panels on the house next year.

--Jon
I have a 15 amp breaker that kept tripping. It was hot to the touch. I now have to wait until I can hook up the computer to 20 amps.
Have your electrician check for a loose connection also. There could be a problem where the wire connects to the circuit breaker (small possibility) or where the circuit breaker plugs onto the electrical panel busbar (greater possibility). It is doubtful that you have a large enough overcurrent to cause the circuit breaker to be hot to the touch.

My guess is that the connection between the breaker and busbar is failing.
Thanks for the info.
Brainfish fan. AMD fan.

jhellis3
Posts: 340
Joined: Fri Aug 16, 2013 10:36 pm

Re: 128-core AMD server

Post by jhellis3 » Sun Nov 26, 2017 2:52 am

I have read over and over that a powerful 8-16 core machine will defeat a 32-64 core machine. After 16 to 20 cores it scales very badly. Has something changed or is this still true?
It was never true? This has more to do with clock speed, heat generation, and power consumption than any sort of scaling issue.

Generally, the more cores per chip the lower the base and boost clocks because you can only dissipate so much heat per mm^2, unless you want to move to water cooling or something more exotic.

But the idea that more cores are somehow inherently bad is just bullshit. Are there diminishing returns, yes. Does performance per dollar drop drastically, yes. But more nodes searched at higher depths will always be better than nothing (provided equal clocks).

jwes
Posts: 772
Joined: Sat Jul 01, 2006 5:11 am

Re: 128-core AMD server

Post by jwes » Sun Nov 26, 2017 8:42 pm

jhellis3 wrote:
What about the argument that its time to depth that matters?
TTD is a useless measurement for LazySMP.
So you're saying that LazySMP finds better moves at equal depths rather than finding the same move faster.

jdart
Posts: 3476
Joined: Fri Mar 10, 2006 4:23 am
Location: http://www.arasanchess.org

Re: 128-core AMD server

Post by jdart » Sun Nov 26, 2017 11:36 pm

Arasan scales quite badly on 32 cores, at present. It is on my to-do list to look at soon.

But other engines do better: Stockfish for example.

Crafty also uses multiple cores efficiently and can hits amazingly high NPS, but I haven't tried it on this 32 core box.

--Jon

Dann Corbit
Posts: 8528
Joined: Wed Mar 08, 2006 7:57 pm
Location: Redmond, WA USA
Contact:

Re: 128-core AMD server

Post by Dann Corbit » Tue Nov 28, 2017 2:55 am

jdart wrote:Arasan scales quite badly on 32 cores, at present. It is on my to-do list to look at soon.

But other engines do better: Stockfish for example.

Crafty also uses multiple cores efficiently and can hits amazingly high NPS, but I haven't tried it on this 32 core box.

--Jon
Texel scales brilliantly
Taking ideas is not a vice, it is a virtue. We have another word for this. It is called learning.
But sharing ideas is an even greater virtue. We have another word for this. It is called teaching.

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