Ivanhoe plays singlecore in TCEC 13 !!

Discussion of anything and everything relating to chess playing software and machines.

Moderators: hgm, Harvey Williamson, bob

Forum rules
This textbox is used to restore diagrams posted with the [d] tag before the upgrade.
Joost Buijs
Posts: 925
Joined: Thu Jul 16, 2009 8:47 am
Location: Almere, The Netherlands

Re: Ivanhoe plays singlecore in TCEC 13 !!

Post by Joost Buijs » Wed Aug 08, 2018 4:45 pm

Milos wrote:
Wed Aug 08, 2018 3:10 pm
Joost Buijs wrote:
Wed Aug 08, 2018 2:58 pm
Milos wrote:
Wed Aug 08, 2018 2:16 pm
There will not be 32 core thread-ripper that blows TCEC machine out or the watter. TDP is the problem. Moore's law is dead, scaling brings almost nothing to CPUs so no way to squeeze 32 cores with manageable TDP (under 300W) that will run on any reasonable frequency (read over 3GHz).
I have a dual CPU system just upgraded it to 2680v2 from 2670. So 20 cores of 5 years old CPUs that perform on par or better than any 20 core v4 Xeon for 1/10 of the cost.
Moore's law is dead, I agree, but still CPU's are getting less power hungry by each new generation. 300W TDP is not very difficult to manage, I've had AMD video-cards drawing 300W from the PS and they were air cooled with just a single fan. If a Noctua NH-D15 can't cope with 300W, you can always switch to water-cooling.

I know that you can buy occasion Xeon CPU's on eBay for peanuts, even complete servers, but you never know in what condition these CPU's are, the servers they sell make so much noise that you don't want to have that in your living environment.

There is also the scaling issue, for chess a machine with 10 cores at 4 GHz. performs better than a machine with 20 cores at 2.5 GHz.
My 6950X CPU runs without any pain at 4.4 GHz. but then it gets somewhat hot under full load (80 to 90 deg. C) so I usually run it at 3.8 GHz. to keep the temperature below 50 deg. C.
OC-ing is nice, and that is advantage of only single CPU system but still those 3.8GHz is not all cores frequency but single core boost. When you are running it for chess on all cores frequency goes down. In your case you may at best get 3.4GHz which is just 10% over 3.1GHz all core frequency that you get from 2680v2.
Yes you might have an issue when buying these old Xeons from ebay or aliexpress, but normally if it is a regular sample taken from server machines chance is pretty high you'd get a fully working CPU that can run for many years more. Old servers are bad for not only terrible noise but also power/heat and especially reliability so I would never buy those.
I guess you never used one of the Intel HEDT processors, when I talk about 4.4 GHz. this is all-core frequency and not some kind of turbo boost for a few cores only. This is the main difference between Xeon server CPU which don't support any kind of OC and the HEDT processors where you can set the clock frequency for each number of cores or per core individually, you can even set the max. allowed TDP and current. The only thing that could happen is that the processor starts throttling when it gets to hot, but that isn't very likely when it runs at 50 deg. C.

syzygy
Posts: 4446
Joined: Tue Feb 28, 2012 10:56 pm

Re: Ivanhoe plays singlecore in TCEC 13 !!

Post by syzygy » Wed Aug 08, 2018 6:34 pm

sedicla wrote:
Tue Aug 07, 2018 11:09 pm
Yes, I can confirm that tucano is showing the node count from the main thread. This should be fixed in the next release.
OK, then that's clear.

This is probably obvious to you, but just in case it's not: make sure to use one node counter per thread and make sure the counters are not all in the same cache line.

Milos
Posts: 3381
Joined: Wed Nov 25, 2009 12:47 am

Re: Ivanhoe plays singlecore in TCEC 13 !!

Post by Milos » Wed Aug 08, 2018 8:23 pm

Joost Buijs wrote:
Wed Aug 08, 2018 4:45 pm
Milos wrote:
Wed Aug 08, 2018 3:10 pm
Joost Buijs wrote:
Wed Aug 08, 2018 2:58 pm
Milos wrote:
Wed Aug 08, 2018 2:16 pm
There will not be 32 core thread-ripper that blows TCEC machine out or the watter. TDP is the problem. Moore's law is dead, scaling brings almost nothing to CPUs so no way to squeeze 32 cores with manageable TDP (under 300W) that will run on any reasonable frequency (read over 3GHz).
I have a dual CPU system just upgraded it to 2680v2 from 2670. So 20 cores of 5 years old CPUs that perform on par or better than any 20 core v4 Xeon for 1/10 of the cost.
Moore's law is dead, I agree, but still CPU's are getting less power hungry by each new generation. 300W TDP is not very difficult to manage, I've had AMD video-cards drawing 300W from the PS and they were air cooled with just a single fan. If a Noctua NH-D15 can't cope with 300W, you can always switch to water-cooling.

I know that you can buy occasion Xeon CPU's on eBay for peanuts, even complete servers, but you never know in what condition these CPU's are, the servers they sell make so much noise that you don't want to have that in your living environment.

There is also the scaling issue, for chess a machine with 10 cores at 4 GHz. performs better than a machine with 20 cores at 2.5 GHz.
My 6950X CPU runs without any pain at 4.4 GHz. but then it gets somewhat hot under full load (80 to 90 deg. C) so I usually run it at 3.8 GHz. to keep the temperature below 50 deg. C.
OC-ing is nice, and that is advantage of only single CPU system but still those 3.8GHz is not all cores frequency but single core boost. When you are running it for chess on all cores frequency goes down. In your case you may at best get 3.4GHz which is just 10% over 3.1GHz all core frequency that you get from 2680v2.
Yes you might have an issue when buying these old Xeons from ebay or aliexpress, but normally if it is a regular sample taken from server machines chance is pretty high you'd get a fully working CPU that can run for many years more. Old servers are bad for not only terrible noise but also power/heat and especially reliability so I would never buy those.
I guess you never used one of the Intel HEDT processors, when I talk about 4.4 GHz. this is all-core frequency and not some kind of turbo boost for a few cores only. This is the main difference between Xeon server CPU which don't support any kind of OC and the HEDT processors where you can set the clock frequency for each number of cores or per core individually, you can even set the max. allowed TDP and current. The only thing that could happen is that the processor starts throttling when it gets to hot, but that isn't very likely when it runs at 50 deg. C.
I was talking about default frequency not overclocking, i7 6950X default boost is 3.5GHz, AVX frequency is 4.0GHz, a and all cores frequency 3.4GHz. The workstation I use at work is exactly i7 6950X machine ofc non-OC, because it is not for kids playing but for professional work that should work reliably 24/7 for months under full workload.
Yes there are extreme OC cases with ppl achieving 4.4 GHz on all cores even up to 5GHz on a single core with like liquid nitrogen cooling, but what is the purpose of that?
99% of 6950X samples cannot get 4.4GHz all core frequency with air cooling. Usually what ppl achieve 4.0-4.2GHz max all cores frequency on air cooling.
And even then you go from 140W TDP to over 250W TDP. Try running machine in that state 24/7 for few months under full load and see how reliable it would become.

Joost Buijs
Posts: 925
Joined: Thu Jul 16, 2009 8:47 am
Location: Almere, The Netherlands

Re: Ivanhoe plays singlecore in TCEC 13 !!

Post by Joost Buijs » Thu Aug 09, 2018 5:21 am

Milos wrote:
Wed Aug 08, 2018 8:23 pm
I was talking about default frequency not overclocking, i7 6950X default boost is 3.5GHz, AVX frequency is 4.0GHz, a and all cores frequency 3.4GHz. The workstation I use at work is exactly i7 6950X machine ofc non-OC, because it is not for kids playing but for professional work that should work reliably 24/7 for months under full workload.
Yes there are extreme OC cases with ppl achieving 4.4 GHz on all cores even up to 5GHz on a single core with like liquid nitrogen cooling, but what is the purpose of that?
99% of 6950X samples cannot get 4.4GHz all core frequency with air cooling. Usually what ppl achieve 4.0-4.2GHz max all cores frequency on air cooling.
And even then you go from 140W TDP to over 250W TDP. Try running machine in that state 24/7 for few months under full load and see how reliable it would become.
Actually I agree with you, the most important thing is stability, although my 6950X has no problems running at 4.4 GHz. I want to keep at least 10% headroom so I usually run it at 3.8 or 4.0 GHz. Intel processors usually have a very large headroom, unlike AMD processors which are overclocked from factory IMHO. Anyway what does it matter, running at 4.0 or 4.4 GHz. it is just 10% difference or for chess 10 Elo max.

I also do professional work with my machines, besides computer-chess (which is one of my hobby's), I used to develop data-acquisition and data-analysis software for the scientific market, recently I retired from that, now I have more time to work on my chess-engine and to bring it up to modern standards.

Post Reply