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2020-07-22, 11:07   #111
paulunderwood

Sep 2002
Database er0rr

D5516 Posts

Quote:
 Originally Posted by ET_ I just noticed the new N2+ has been announced. BTW, how do you deal with the big-little 6-cores architecture? You probably already told us, but I lost the pointer, and if you have it at hand...
I only use the a73. The a53 is idle. It is best to have two processes for 2 processors. I might fire up a double check for the a53. Running wavefront on it is too slow!

2020-07-22, 21:40   #112
ewmayer
2ω=0

Sep 2002
República de California

2×13×443 Posts

Quote:
 Originally Posted by paulunderwood I only use the a73. The a53 is idle. It is best to have two processes for 2 processors. I might fire up a double check for the a53. Running wavefront on it is too slow!
DCs-on-the-a53 was what I was doing on my N2 early last summer, before I sold it off for medical experiments sold it to PaulL and shipped off to Las Canarias. From my post #46 (page 5 of the thread):
Quote:
 Those timings reflect no crunching going on on the a53 CPU - with jobs running on both you can expect a 5-10% timing hit. On my N2 a first-time LL-test with p ~ 89M [5120K FFT] is getting ~110ms/iter 4-threaded on the a73, thus ~4 months per test; a DC with p ~50M [2816K FFT] is getting ~220ms/iter 2-threaded on the a53. The latter core is only half as strong as the quad-a53 on my Odroid C2, so even DCs run painfully slowly on it. The quad Snapdragon CPU in each of my dozen Galaxy S7 broke-o-phones is about the same speed as the N2's quad-a73 core, by way of comparison.
Had not heard about the new N2 - what are the major upgrades vs last year's model?

2020-07-22, 21:50   #113
paulunderwood

Sep 2002
Database er0rr

1101010101012 Posts

Quote:
 Originally Posted by ewmayer Had not heard about the new N2 - what are the major upgrades vs last year's model?
Quote:
 ODROID-N2+ is a revision from ODROID-N2. – Maximum CPU clock of Quad-core Cortex-A73 is increased to 2.4Ghz from 1.8Ghz. – Maximum CPU clock of Dual-core Cortex-A53 is increased to 2.0Ghz from 1.9Ghz. – On-board RTC backup battery holder is mounted on the board.
According to this page. That is going to one hot a73, lthough it does have a optional active cooler, similar to how I set up my N2 with a USB fan. The N2+ has a nice double precision boost over the N2.

Last fiddled with by paulunderwood on 2020-07-22 at 22:03

2020-07-22, 22:21   #114
ewmayer
2ω=0

Sep 2002
República de California

2·13·443 Posts

Quote:
 Originally Posted by paulunderwood According to this page. That is going to one hot a73, lthough it does have a optional active cooler, similar to how I set up my N2 with a USB fan.
I was just viewing the same HK page - well, the 2GB-model-one in my case. Was briefly hopeful of upgrade to a quad-a53, no such luck, though the extra N2 speed should provide a bigger performance boost than 2 additional a53 cores would've. Re. heat, the HK blurb says
Quote:
 Thanks to the modern 12nm silicon technology, the A73 cores run at 2.2Ghz without thermal throttling using the stock metal-housing heatsink allowing a robust and quiet computer. The CPU multi-core performance is around 20% faster and the GPU is 10% faster than the N1. The N2+’s DDR4 RAM is running at 1320Mhz with 1.2volt low power consumption.
Not sure re. "1.2volt lower power" - I thunk they mean 1.2 watt lower. Which would imply lower heat, at least from the RAM. And I *really* hope they mean 20% faster than N2, not N1 - see quote below. The 12nm stuff - was hopeful this would represent a process-shrink vs N2, again, no - aside from the upped frequency, above is the identical wording they used for the N2:
Quote:
 Thanks to the modern 12nm silicon technology, the A73 cores runs at 1.8Ghz without thermal throttling using the stock metal-housing heatsink allowing a robust and quiet computer. The CPU multi-core performance is around 20% faster and the 4GByte DDR4 RAM is 35% faster than the N1. The N2’s DDR4 RAM is running at 1320Mhz while N1’s DDR3 was running at 800Mhz.
I ran my N2 w/o any special airflow provisioning, don't recall any significant throttling. Even if N2 is worse in that regard, I've now had plenty of experience "creating airflow on my desktop" - for last spring broke-o-phone-cluster project used simply USB fans, for my current R7-based desktop supercruncher I'm getting great results from a simply $15 compact plug-in desktop fan to blow air over the whole array of GPUs. For the N2, small and low-watts as it is, I would expect you might get adequate cooling by setting, say, on top of the top-of-case vent fan on an ATX case system, sitting on its side so as to not impede the airflow. Remember, you don't need room-temp airflow to cool a CPU that begns to throttle at 80-90C, even a prewarmed-by-other-devices air stream is fine as long as it's less than, say 60C. The N2's huge heat sink should make things quite easy. Oh, I'm now down to 1 sole broke-o-phone whose battery still takes at least a partial charge, allowing the unit to boot. So I have a 5-slot USB charging station (the 2nd is going to my sister's conneted household) and a pair of USB fans, free to good homes, just pay my shipping expense. Setting an N2 next to or atop the face of a USB fan should work quite well. Just PM me with your address - sorry, US only, inetrnational shipping has become a massive and expensive hassle in last decade or so. Shipping Paul's N2 last year took the better part of an afternoon waiting in line at USPS and filling out forms, and cost$25 for a small 1lb package. No, thanks. If you are non-US but know someone here who will be in your neck of the woods in near future, I'd be happy to ship to them.

Last fiddled with by ewmayer on 2020-07-22 at 22:23

2020-07-23, 06:42   #115
xilman
Bamboozled!

"𒉺𒌌𒇷𒆷𒀭"
May 2003
Down not across

5×2,053 Posts

Quote:
 Originally Posted by ewmayer DCs-on-the-a53 was what I was doing on my N2 early last summer, before I sold it off for medical experiments sold it to PaulL and shipped off to Las Canarias.
I arrived in La Palma roughly 36 hours ago. Air travel is different these days. At least I was allowed into the country.

The N2 is still here. I need to source (i.e. probably write) an INDI driver for the dome controller before it can be put into full use. One of the projects for this visit.

Last fiddled with by xilman on 2020-07-23 at 06:43

2020-07-23, 08:45   #116
henryzz
Just call me Henry

"David"
Sep 2007
Cambridge (GMT/BST)

2·2,861 Posts

Quote:
 Originally Posted by xilman I arrived in La Palma roughly 36 hours ago. Air travel is different these days. At least I was allowed into the country. The N2 is still here. I need to source (i.e. probably write) an INDI driver for the dome controller before it can be put into full use. One of the projects for this visit.
How are the restrictions there currently? A quick google suggested it may be eliminated there.

2020-07-23, 09:24   #117
xilman
Bamboozled!

"𒉺𒌌𒇷𒆷𒀭"
May 2003
Down not across

5·2,053 Posts

Quote:
 Originally Posted by henryzz How are the restrictions there currently? A quick google suggested it may be eliminated there.
Similar to those in the UK. This is seriously off-topic and further discussion should take place elsewhere.

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