The hardware enthusiast's corner (2)

It is customary at other project's forums for when threads become to long or unwieldy to close the original thread and create its successor thread with an enumeration typically.

Assembling a computer for working BOINC is not only building it, but also maintaining for it being in perfect shape for hard and reliable crunching.
For me, this gives sense for "The hardware enthusiast's corner (2)" thread.

It's delightful that a self-built host ends up serving for something useful!!
My preferent BOINC project is Gpugrid, but I have several other backup projects for productively filling the ACEMD3 / Python tasks scarcity periods like previous weeks.
I've been recently notified by PrimeGrid about my Gpugrid Host #557889 being discoverer of an unknown Prime number large enough for entering the Top 5000 List in Chris Caldwell's The Largest Known Primes Database.
The number: 95635202^131072+1

Here, a recent image of the inside of the lucky host.



The harboring chassis was recovered from scrap to give it a second life... ✅
It's something that we can expect from a hardware enthusiast ;-)

Congratz on the new prime number discovery.

Looking forward to your insights and knowledge in the new thread.

Upgrading system RAM, It's easy

If you're able to exchange your car's wheel without calling a tow truck, then, for sure, you're able to upgrade your system's RAM.
(And even if you aren't, I'd say that you're still able to upgrade your system's RAM ;-)

When new batches of ABOU Python GPU tasks arised, I got in problems with my two Multi-GPU hosts.
My triple GTX 1650 GPU system had installed 32 GB of system RAM, while my twin GTX 1650 GPU system had 16 GB RAM installed.
Grossly, each ABOU task needs 16 GB of system RAM to expand its environment. Therefore, I had to take care for my Triple GPU system not to get more than two ABOU simultaneous tasks, and my twin GPU system more than one...
So I decided to upgrade my triple GPU system from 32 to 64 GB RAM (and by carom, my twin GPU system from 16 to 32 GB RAM).

First of all, please, seat down a few minutes to study your move. Otherwise, you may get a nasty surprise...

As an example, take a look to Gigabyte B365M H motherboard specifications. Two of my hosts are based on it.
At Memory specifications section, it's said that maximum allowed RAM size is 2 x DDR4 @2666 MHz DIMMs up to a total of 32 GB system RAM.
This system can't handle 64 GB RAM. Installing 2 x 32 GB DIMMs will cause that system even won't start!

Here are specifications for the motherboard of the two systems to upgrade: Gigabyte Z390 UD
It can handle 4 x DDR4 @2666 MHz DIMMs up to a total of 128 GB system RAM, with maximum size of 32 GB DDR4 modules. Good!
I opened my hardware piggy bank and purchased 2 x DDR4 @2666 MHz 32 GB DIMMs.
The starting configuration for my triple GPU system was this 4 x DDR4 @2666 MHz 8 GB DIMMs = 32 GB total system RAM.
Upgrading is as simple as opening the computer's case, extract the four existing DIMMs, and install the two new ones.

Here one tip, based in my experience:
When I install a new slot-based component (memory DIMM, graphics card, expansion card) I insert and extract and reinsert it three times.
This is what I call the slot and the module contacts "becoming friends". This usually will prevent present and future problems due to poor electric contacts.
If modules refuse to enter, try turning them by 180º... They are "mechanically codified".
Always verify at the end that DIMM is fully inserted into the slot, and lateral latches are all the way closed.
When in doubt, there is usually a section on motherboard's manual explaining how the memory modules are to be installed depending on each model.

Now, the new system's memory section looks like this.
As you can see, I've installed both memory modules at slots of the same (grey) color. Please, take care of doing this way for taking advantage of dual channel memory performance enhancement.
Also it is described at each motherboard user manual when multi-channel memory architecture is available.

And the four extracted DIMM modules from previous system, are now re-used to replace the existing 16 GB RAM at my twin GPU system to upgrade to 32 GB.
Here is its final new look.

After that, My triple GPU system has been able to successfully process three concurrent ABOU tasks without worrying about a lack of system RAM.
This is a screenshot of BOINC Manager while they were processing.
Also I took a nvidia-smi screenshot.
And the following Psensor screenshot, where the typical "GPU spikes" caused by the learning agents can be appreciated:



Even a 6% of system RAM remains still available at this full load situation.

In the same way, my twin GPU system is able to process two concurrent ABOU tasks without worrying about it.

It was worth it! 👍️

Woke today to find 8 Linux Mint 20.3 computers no longer able to communicate. When I put a head on them I can find nothing out of the ordinary except that it cannot communicate with the internet.
Strangely one computer can communicate over my LAN but cannot communicate with the internet.
Each has a static IP and I keep them updated.
I turned off all my switches and turned them back on starting from the hub. I've also rebooted several of them.
Any suggestions would be welcome. TIA

For the commoner DHCP-allocated IP addresses, you don't just get an IP address. You also need (and get):

Subnet mask
Default gateway
DNS server

Of those three, the most likely culprit is the default gateway. Have you changed or reconfigured your router recently?

For the commoner DHCP-allocated IP addresses, you don't just get an IP address. You also need (and get):
Subnet mask (255.255.255.0)
Default gateway (192.168.1.1, just checked and it still has this address)
DNS server (8.8.4.4,8.8.8.8)
Of those three, the most likely culprit is the default gateway. Have you changed or reconfigured your router recently?

check the cables too, just as a quick check. or even specific ports on the switch could go bad. try a different port or known/good port.

what is the result of 'ifconfig' from a terminal? or 'ip a' if you don't have the ifconfig package installed

____________

I connect to the Internet at home by means of a fiber optics line from my supplier.
From time to time, I lose the whole Internet connection with no apparent reason (not your case, a partial loss)
I then switch off everything but Ethernet switches, and start booting the Optical Node Terminal (ONT), then the Internet Router, and finally the WiFi access points. This usually solves my problem.

Recently, I noticed a linux-firmware update. If Linux OS, you could check for a common NIC at non-connecting hosts that would be affected by this update in some way.
Trying momentarily with any trusted USB - Ethernet or USB - WiFi device could help to diagnose something like that.

Solved, I hope. A couple of days ago I shut down my network and powered it from the router to the hub switch... That seemed to fix things. I thought maybe a glitchy computer messed up the address tables in the switches.
Today I woke to find a big list of completed WUs that would not upload. Moved cables but problem followed the computers and not the cables. Shut down and rebooted network. Didn't fix it. For some reason I opened my router gui and clicked on one of the 7 hung computers. For some reason it had turned the parental control to Deny Monday on a few of them. I clicked Allow Monday and they worked. A couple showed Allow All. These two required that I click Deny All, wait for it to set, and then click Allow All. Then they worked. First I had tried All Devices Allow All but that only timed out before it completed applying it.

Now I'm wondering if my Charter Spectrum WiFi router model Sagemcom F@st 5260 needs to be replaced.

Thinking of buying a WiFi router with 8 LAN ports so I can get rid of the Spectrum rental and my hub switch. Something like this but it's expensive:
https://www.newegg.com/asus-rt-ax88u-ca-ieee-802-11a-ieee-802-11b-ieee-802-11g-ieee-802-11n-ieee-802-11ac-ieee-802-11a/p/N82E16833320374?Item=9SIAD6H9RM4620&quicklink=true
Or maybe this reburished one that's much cheaper: https://www.newegg.com/tp-link-archer-c5400x/p/N82E16833704584?quicklink=true
Maybe having the hub switch is okay so I could use a 4 LAN port router. Or maybe there's a WiFi router that can be attached to a non-WiFi 8 LAN router.

I have been having very slow website populations lately across the board so I just ran my two command line statements to refresh everything. Boom! now all the websites populate fast and normally.

sudo ip -s -s neigh flush all


sudo systemd-resolve --flush-caches

an old router could certainly be an issue and have all kinds of weird problems.

if you feel able, you could build your own router from an old PC. it doesn't require much power. pfSense is very robust and stable router software.

I run my router on pfSense using an Intel Atom 8-core processor and 8GB ECC RAM. which is more than enough to run my VPN and several packet related services in addition to all the routing functions.

the only downside is the initial configuration, and you'll need a switch and some access points for wifi. but the plus side is you get the flexibility to choose your own wifi access points and you can put them wherever you want. getting whole home wifi coverage is a lot easier with a few well placed APs than with a single consumer grade router that usually has bad radio/antenna properties and anemic hardware.
____________

For some reason I opened my router gui and clicked on one of the 7 hung computers. For some reason it had turned the parental control to Deny Monday on a few of them. I clicked Allow Monday and they worked. A couple showed Allow All. These two required that I click Deny All, wait for it to set, and then click Allow All. Then they worked.

Always there is a first time

On a routine temperature screening of my working hosts, today I found a graphics card based on a Nvidia GT 1030 GPU showing 82 ºC
A normal Psensor screenshot for that host looks like this. Around 54 ºC at full load for GT 1030 GPU.
That ASUS PH-GT1030-O2G graphics card is a 30 Watts low power consumption one, so the abnormally high temperature must have any explanation...
...Jumping jack fan, for example?

Once the card on the table, it can be seen that the blades had completely detached from the fan's body.
Digging in my backup fan collection, I found a PWM fan directly compatible with the damaged one.
After a thorough heatsink clean and replacing the fan, the graphics card is ready to work again.

I had never found so far anything like this... But always there is a first time.

Woke today to find 8 Linux Mint 20.3 computers no longer able to communicate. When I put a head on them I can find nothing out of the ordinary except that it cannot communicate with the internet.
Strangely one computer can communicate over my LAN but cannot communicate with the internet.
Each has a static IP and I keep them updated.
I turned off all my switches and turned them back on starting from the hub. I've also rebooted several of them.
Any suggestions would be welcome. TIA

Now I'm wondering if my Charter Spectrum WiFi router model Sagemcom F@st 5260 needs to be replaced.

Thinking of buying a WiFi router with 8 LAN ports so I can get rid of the Spectrum rental and my hub switch.