Bigger nbody tasks?

Author	Message
Mr P Hucker Send message Joined: 5 Jul 11 Posts: 990 Credit: 376,143,149 RAC: 0	Message 74836 - Posted: 20 Dec 2022, 1:02:29 UTC Am I right in thinking nbody used to be pretty quick - about 20 minutes on a Ryzen 9 3900XT (33,000 CPUMark)? Now they're taking 40 minutes to 1 hours 20 minutes. Have the tasks increased in size? ID: 74836 · Rating: 0 · rate: / Reply Quote

HRFMguy Send message Joined: 12 Nov 21 Posts: 236 Credit: 575,038,236 RAC: 0	Message 74837 - Posted: 20 Dec 2022, 2:00:35 UTC - in response to Message 74836. Am I right in thinking nbody used to be pretty quick - about 20 minutes on a Ryzen 9 3900XT (33,000 CPUMark)? Now they're taking 40 minutes to 1 hours 20 minutes. Have the tasks increased in size? Haven't run those since the big crunch. How many CPUs per task are you running? IIRC I was running 4 CPU at a whack, and it was taking about 3 minutes each. ID: 74837 · Rating: 0 · rate: / Reply Quote

Mr P Hucker Send message Joined: 5 Jul 11 Posts: 990 Credit: 376,143,149 RAC: 0	Message 74838 - Posted: 20 Dec 2022, 2:09:58 UTC - in response to Message 74837. Last modified: 20 Dec 2022, 2:11:46 UTC Am I right in thinking nbody used to be pretty quick - about 20 minutes on a Ryzen 9 3900XT (33,000 CPUMark)? Now they're taking 40 minutes to 1 hours 20 minutes. Have the tasks increased in size? Haven't run those since the big crunch. How many CPUs per task are you running? IIRC I was running 4 CPU at a whack, and it was taking about 3 minutes each. I have no idea what "at a whack" means. I'm running 3 of them on a 24 core CPU (Ryzen 9 3900XT), so 8 cores each. But the times I quoted were divided by 3 to show how long one would take if it was using all 24 cores. I'm sure that time used to be 20 minutes, but now it's 2-4 times longer. As for the big crunch - you've got way more RAC than me! ID: 74838 · Rating: 0 · rate: / Reply Quote

mikey Send message Joined: 8 May 09 Posts: 3339 Credit: 524,010,781 RAC: 0	Message 74840 - Posted: 20 Dec 2022, 11:05:05 UTC - in response to Message 74838. Am I right in thinking nbody used to be pretty quick - about 20 minutes on a Ryzen 9 3900XT (33,000 CPUMark)? Now they're taking 40 minutes to 1 hours 20 minutes. Have the tasks increased in size? Haven't run those since the big crunch. How many CPUs per task are you running? IIRC I was running 4 CPU at a whack, and it was taking about 3 minutes each. I have no idea what "at a whack" means. I'm running 3 of them on a 24 core CPU (Ryzen 9 3900XT), so 8 cores each. But the times I quoted were divided by 3 to show how long one would take if it was using all 24 cores. I'm sure that time used to be 20 minutes, but now it's 2-4 times longer. As for the big crunch - you've got way more RAC than me! At a whack is the same at a time, and yes the tasks are bigger because they are doing a new section of the sky and the initial tasks are larger but as they go thru them they tend to get smaller because there's less stuff in the data to analyze ID: 74840 · Rating: 0 · rate: / Reply Quote