| Index | Recent Threads | Unanswered Threads | Who's Active | Guidelines | Search |
 |
World Community Grid Forums
Category: Active Research
Forum: OpenPandemics - COVID-19 Project
Thread: CPU cache & performance |
| No member browsing this thread |
|
Thread Status: Active Total posts in this thread: 31
|
|
| Author |
|
|
Sasha Leykatze
Cruncher United Kingdom Joined: Feb 25, 2019 Post Count: 9 Status: Offline Project Badges: 
|
Zen2 has a 16MB chunk of L3 cache per 4 cores (CCX) so I expect 3950X to have less performance per core than 3900X since the latter has only 3 active cores per 16MB chunk of L3.
A single core on Zen2 only has lookup tables for ultra fast access to up to 8MB of L3 cache. It can walk the remaining 8MB for a total of 16MB at slightly less speed. Anything over 16MB on a single thread/workunit is accessed at an unviable speed for fast computation / would go to RAM instead. Even EPYC ROME (256MB L3) is not as unified L3 cache. The package contains 8 CCD chiplets with dual 16MB caches, each cache attached to 4 cores only. Seeking outside of the 16MB cache results in huge latency penalty/going to RAM instead. All CCXs in all CCDs communicate via central IO/D, even on the same chiplet. TLDR: 8, 16, 32 and 64C Zen2 CPUS have the exact same cache performance from a single-core /work unit perspective. 6, 12, 24, 48C core Zen2 CPUs have slightly more L3 cache available in such scenario, due to the fact that their CCXs have a disabled core: 3 core / 16MB vs 4 core / 16MB I have a 3950X in case you wanted me to test. |
||
|
|
yoerik
Senior Cruncher Canada Joined: Mar 24, 2020 Post Count: 413 Status: Offline Project Badges:
|
:D I mean stuff like Pentium IV. The last one I had used 100 watts idle and 200 watts running a single WCG task. Years ago... TBH I'm only able to do this because of reduced hydro rates due to COVID-19. I'd only be able to run my devices (2 laptops, 3 androids) 24/7 on weekends without the temporary change to rates. But wow, how technology evolves. The Pentium I'm using to type this rn, is quad-core and handles 4 tasks at once like a pro. I mean, it would be far better if I had a better CPU, but every little bit helps?  it caps out at 5 Watts, and doesn't break above 75 degrees Celsius (with the safe max being 90) The Intel Z3740 tablet I have is also a quad-core and uses little power too. Not very fast (9-10 hours for OPN) but it has been running basically non-stop 24/7 since May 2018. The touchscreen is not working so it would be useless to me if not for WCG. Costs like just over €1 a month. I really like these little power devices. Also have an Intel N2810 2.1 GHz 2-core that uses 9 watts but I'm not running it right now. Maybe I need try it out again. (for a while a few years ago, I even shut down my main PC at the time, the A8-6500, and used the N2810 because it was so low power and I love efficiency) So yes, that Pentium looks great  , of course it helps!over 8 hours to run one OP WU on the Pentium - over 20 hours on my android devices - but it's something lol. I'm glad that I'm able to contribute SOMETHING lol. Crunch on, Falconet. Keep up the good work - both with your crunching, and your helpfulness in the forums for WCG. 5 stars and a big air-hug of thanks from me to you, for it.  |
||
|
|
kinski
Advanced Cruncher Joined: Nov 25, 2006 Post Count: 104 Status: Offline Project Badges: 
|
Im running 3950x @65W ECO TDP, will do some PPH calculations shortly.
----------------------------------------edit: 39,3 points/core/hour - the CPU runs COVID WUs @3.5Ghz all core  [Edit 2 times, last edit by kinski at May 19, 2020 3:04:41 PM] |
||
|
|
Falconet
Master Cruncher Portugal Joined: Mar 9, 2009 Post Count: 3315 Status: Offline Project Badges: 
|
:D I mean stuff like Pentium IV. The last one I had used 100 watts idle and 200 watts running a single WCG task. Years ago... TBH I'm only able to do this because of reduced hydro rates due to COVID-19. I'd only be able to run my devices (2 laptops, 3 androids) 24/7 on weekends without the temporary change to rates. But wow, how technology evolves. The Pentium I'm using to type this rn, is quad-core and handles 4 tasks at once like a pro. I mean, it would be far better if I had a better CPU, but every little bit helps? it caps out at 5 Watts, and doesn't break above 75 degrees Celsius (with the safe max being 90) The Intel Z3740 tablet I have is also a quad-core and uses little power too. Not very fast (9-10 hours for OPN) but it has been running basically non-stop 24/7 since May 2018. The touchscreen is not working so it would be useless to me if not for WCG. Costs like just over €1 a month. I really like these little power devices. Also have an Intel N2810 2.1 GHz 2-core that uses 9 watts but I'm not running it right now. Maybe I need try it out again. (for a while a few years ago, I even shut down my main PC at the time, the A8-6500, and used the N2810 because it was so low power and I love efficiency) So yes, that Pentium looks great , of course it helps!over 8 hours to run one OP WU on the Pentium - over 20 hours on my android devices - but it's something lol. I'm glad that I'm able to contribute SOMETHING lol. Crunch on, Falconet. Keep up the good work - both with your crunching, and your helpfulness in the forums for WCG. 5 stars and a big air-hug of thanks from me to you, for it. No problem, yoerik. You are contributing and doing so in a rather efficient way. Kind regards  - AMD Ryzen 5 1600AF 6C/12T 3.2 GHz - 85W - AMD Ryzen 5 2500U 4C/8T 2.0 GHz - 28W - AMD Ryzen 7 7730U 8C/16T 3.0 GHz |
||
|
|
fuzzydice555
Advanced Cruncher Joined: Mar 25, 2015 Post Count: 89 Status: Offline Project Badges: 
|
Im running 3950x @65W ECO TDP, will do some PPH calculations shortly. edit: 39,3 points/core/hour - the CPU runs COVID WUs @3.5Ghz all core Thanks, this is interesting! Even though my 3700X and your 3950X has around the same frequency and cache per core, your CPU runs a bit faster. Ryzen 3700X 32MB @3.6 GHz: 34,06 points/hour/core Ryzen 3900X 64MB @3.8 GHz: 47,49 points/hour/core I checked another batch of 15 work units to make sure this is not a one time fluctuation, the current average is 47,93 points for the 3900X. With this information, I think I will stay with the 3900X until Ryzen 4000.  |
||
|
|
Former Member
Cruncher Joined: May 22, 2018 Post Count: 0 Status: Offline |
I'm running a 3990x for OPN, I have SMT (hyper threading) turned off so I'm running 60 threads/60 WU simultaneously. The runtime is avg 1.2 hours with 80 points avg, so approx. 65 points/hour/core. This chip has 256mb of L3 cache. It's running approx. 3.6Ghz
If I run with SMT on the best case is 102 threads so my project time accrues far faster, but it takes between 2.5-3 hours per WU so actual work is less. |
||
|
|
kinski
Advanced Cruncher Joined: Nov 25, 2006 Post Count: 104 Status: Offline Project Badges:
|
 Past 24h of COVID-19 WUs (360 WUs) on R9 3950x/SMT on/65W ECO mode/4x16GB 3200cl16. Average points/core/hour - 39.56779159 Median points/core/hour - 39.65936538 Average run time per WU - 2,1h I'll try 3400cl16, 3600cl16 and 3733cl16 for a day to see what effect it has. [Edit 1 times, last edit by kinski at May 20, 2020 8:51:25 AM] |
||
|
|
Former Member
Cruncher Joined: May 22, 2018 Post Count: 0 Status: Offline |
The credit system is still fantastically broken so you need really long term averages to get any reasonable measure. My tablet today shows granted BOINC creditS of 483 and 246 per job to be multiplied by 7 to get WCG points. My desktop has one today with 145 credit, 33 per hour.
|
||
|
|
kinski
Advanced Cruncher Joined: Nov 25, 2006 Post Count: 104 Status: Offline Project Badges:
|
I'm running my 3950x @65W TDP and memory @3533cl16. Will report back on performance in couple days.
---------------------------------------- |
||
|
|
pututu
Senior Cruncher United States Joined: Jan 3, 2016 Post Count: 243 Status: Offline Project Badges:
|
I'm running 3950x at 3.5GHz at 0.97V, all 32 threads. I use MSI B450 tomahawk max motherboard with 3200CL16 memory. Pulling about 127W off the wall.
---------------------------------------- |
||
|
|
|