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What is "HadAM4 at N216 resolution v8.52"?

What is "HadAM4 at N216 resolution v8.52"?

Message boards : Number crunching : What is "HadAM4 at N216 resolution v8.52"?
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Jim1348

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Message 62317 - Posted: 20 Apr 2020, 17:07:28 UTC

This is apparently the current work unit, and the last one I ran, but don't see a description for it.
But before taking resources off of coronavirus, I am wondering what it is?
The files include "ozone" and "solar", so it could be important in those areas.
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Message 62321 - Posted: 20 Apr 2020, 19:44:54 UTC - in response to Message 62317.  

This is apparently the current work unit, and the last one I ran, but don't see a description for it.
But before taking resources off of coronavirus, I am wondering what it is?
The files include "ozone" and "solar", so it could be important in those areas.


HadAM4 at N216 resolution v8.52 is the new Linux only model. From what I’ve read it requires a lot of RAM (about 4GB per core) to run well.
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Jim1348

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Message 62323 - Posted: 20 Apr 2020, 20:42:19 UTC - in response to Message 62321.  

OK, a lot of RAM I can do. In fact, I was hoping for that. But I am wondering what the science is?
They usually have a description on the cover-page, but nothing now.
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Les Bayliss
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Message 62324 - Posted: 20 Apr 2020, 21:47:00 UTC

It's part of DOCILE:
DOCILE (Drives Of Change In mid-Latitude weather Events)
The only other info is in HadAM4 at N216 resolution
(The post from the researcher.)

The 4 Gigs refers to L3 cache.
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Jim1348

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Message 62325 - Posted: 20 Apr 2020, 21:48:49 UTC - in response to Message 62324.  

OK, I will give it a couple of cores to start.

Thanks.
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Jean-David Beyer

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Message 62326 - Posted: 20 Apr 2020, 22:16:32 UTC - in response to Message 62321.  

HadAM4 at N216 resolution v8.52 is the new Linux only model. From what I’ve read it requires a lot of RAM (about 4GB per core) to run well.


I got four of those on my relatively slow machine. One of them crashed soon after the second trickle (in Message 62299 - Posted: 13 Apr 2020, 12:16:51 UTC ), but the other three seem to be running OK. One has done three trickles and the others, two each.

As far as RAM is concerned, they seem to take about the same as all N216 models.
VIRT RES SHR
1383m 1.3g 15m

Memory 15.5 GB
Cache 10240 KB
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Profile Alan K

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Message 62327 - Posted: 20 Apr 2020, 22:39:48 UTC - in response to Message 62324.  


The 4 Gigs refers to L3 cache.


More likely to be 4Mb L3 cache. My I5 has 6Mb L3 and handles 3 tasks reasonably well, but is faster running only 2 by about 15% (32sec/ts vs 38sec/ts).
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Jim1348

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Message 62328 - Posted: 20 Apr 2020, 23:06:24 UTC - in response to Message 62327.  

More likely to be 4Mb L3 cache. My I5 has 6Mb L3 and handles 3 tasks reasonably well, but is faster running only 2 by about 15% (32sec/ts vs 38sec/ts).

I normally load up as many as the CPU will take without a big slowdown. That is usually four on my machines.

But this time, I am trying one at a time on each of several machines:
i7-9700 (eight full cores)
i7-8700 (twelve virtual cores)
Ryzen 3700X (sixteen virtual cores)
Ryzen 3600 (twelve virtual cores)
Ryzen 2700 (sixteen virtual cores)
Ryzen 2600 (twelve virtual cores).

I know which ones will do best, but by how much is not clear.
Each machine has Rosettas on the other cores, so they should be more or less equal in that regard.
The question will be whether it is better to run more of them on a few machines, or fewer of them on many machines.

The most interesting would be my new Ryzen 3950X, but it is tied up full time on Folding.
If Oxford can get their vaccine to work, I can return it to other duties.
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Les Bayliss
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Message 62329 - Posted: 21 Apr 2020, 1:21:41 UTC - in response to Message 62327.  
Last modified: 21 Apr 2020, 1:22:04 UTC


The 4 Gigs refers to L3 cache.


More likely to be 4Mb L3 cache. My I5 has 6Mb L3 and handles 3 tasks reasonably well, but is faster running only 2 by about 15% (32sec/ts vs 38sec/ts).


Ah, yes. I know it's 4 something. :(
It was discussed at length in the special thread for those models.

And perhaps to look at them from a different point:
They're not researching specific events, the way that the Attribution models do.
They're collecting hi-res data points far into the future, for the benefit of climate modellers looking way down the track to plan for "something".
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Jean-David Beyer

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Message 62330 - Posted: 21 Apr 2020, 11:48:30 UTC - in response to Message 62324.  

The 4 Gigs refers to L3 cache.


So when I look at the processor using cpdn web site, and it says

CPU type GenuineIntel
Intel(R) Xeon(R) CPU E5-2603 0 @ 1.80GHz [Family 6 Model 45 Stepping 7]
Number of processors 4

Memory 15.5 GB
Cache 10240 KB


to which cache does it refer?
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Jim1348

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Message 62332 - Posted: 21 Apr 2020, 20:33:21 UTC - in response to Message 62330.  

Cache 10240 KB
to which cache does it refer?

I think they just add L1 + L2 + L3 to get that number, from the ones I have seen.
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Message 62333 - Posted: 21 Apr 2020, 21:45:39 UTC - in response to Message 62330.  

The E5-2603 processor is a Sandy Bridge.
Look at this page
Find the processor, then move across to the L3 Cache column. It says 10 MB.
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Harri Liljeroos
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Message 62337 - Posted: 22 Apr 2020, 10:17:53 UTC - in response to Message 62333.  

I don't know where Boinc gets these cache values, but my I7-7820X shows here to have 256 KB cache and wikipedia shows L2 = 8 x 1024 KiB and L3 = 11 MiB.
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Message boards : Number crunching : What is "HadAM4 at N216 resolution v8.52"?

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