October 20, 20214 yr 1 hour ago, citizengray said: Wow. I actually still can't believe that the whole of this seems (to be confirmed) to be due to the power delivery to the cages. Yeah, the cross sectional area of wire and all the contact points in the chain are very important to keep the voltage steady under load. Longer runs need thicker wires, and every junction MUST have a large solid contact patch. 4 pin connectors are better than the SATA power wires, but only if the pins and sockets are all precisely the correct dimensions, not bent or corroded.
October 20, 20214 yr 1 minute ago, citizengray said: Understood. I purchased 16 gauge cable, do you think this is enough ? Should be fine for reasonable lengths and drive counts. The root issue is the voltage drop from one end to the other, so amps and gauge aren't enough information, you need total length of run as well. 16 gauge is plenty thick for a 1 foot run powering up 10 spinning hard drives, and not nearly thick enough for 250 feet. There are calculators online for voltage drop and such, but you have to make some assumptions about just how tolerant your drives are to low voltage. In general a properly put together custom system should be leaps and bounds better than a few generic splitters and extenders, especially when they are using cheap stamped pins and aluminum wire.
October 21, 20214 yr Author Sounds good. Thx. On another note, I finished the partiy check and the array is now function - albeit all of the place in term of connection (some drive through cages and some directly) - this obviously temporary. However I am still very much concerned from a performance stand point. Right now I have 2 parity drive and 1 data drive (for now), each drive is at least able to individually able to read/write at at least ~150mb/s (sustained). But when I copy something to the only share I created on the Array, the best copy speed I get is ~11-12mb/s ... it feels abysmally small. I have disabled the cache for this share though to purposefully test the array speed. Any idea what could be happening ?
October 21, 20214 yr Author I just ran a test by creating a new share and made it "cache" only. And weirdly enough... I guess the same write speed (~11-12 mb/s) on NVME drives that are able to write at 1000mb/s...
October 21, 20214 yr Check network, those speeds sound suspiciously like a 100Mb connection somewhere in the chain.
October 21, 20214 yr Author Oh indeed they do ! Just ran LibreSpeed and indeed... my speed is 99.8 Mbps... It is supposed to be plugged on a 10Gb interface connected to a 1GB switch. I'll double check the network...
October 21, 20214 yr Author Yep ok that was it... Seems I had a faulty network cable. Swapped it and got back in 1Gb. Ran LibreSpeed again, now getting 994-8 Mbps in Download, however in upload I am somehow limited to ~750 Mbps When actually running file copying to either Cache or Array, I get a sustained 116MB/s, so very close to the theoretical limit of the bandwidth, so nothing to complain about ! Don't know how I missed that ! Thx
October 21, 20214 yr Community Expert 22 hours ago, citizengray said: Wow. I actually still can't believe that the whole of this seems (to be confirmed) to be due to the power delivery to the cages... f*cking Y splitters... Pulled my hair out for a long time, too. Hell, for almost 2 years I just didn't do parity checks because I was tired of drives dropping
October 22, 20214 yr Author Yeah... I feel you. Hopefully that custom cable that I making will do the trick ! Since I plugged the cages and the drive directly on the PSU cable (no Y Splitters) it has been incredibly stable, so I am very much looking forward to being able to reinstall everything properly.
October 22, 20214 yr Community Expert 1 hour ago, citizengray said: Yeah... I feel you. Hopefully that custom cable that I making will do the trick ! I ended up adding passthru punch down connectors to my PSU's unused SATA power lines, worked great. Cost me 5 bux on ebay
October 22, 20214 yr Community Expert 30 minutes ago, citizengray said: Not familiar with those, do you mind sharing a link ? Here's one https://www.ebay.com/itm/251295075570
October 24, 20214 yr Author I am extremely happy that after building that custom Molex cable everything seems to be working great ! Haven't had a single disk dropped yet, launched pre-clear on like 7 drives to stress the system and so far all is good. As mentioned before I connected directly to the PSU 2 molex cables - 5 molex plugs on each using 16 gauge cable. Thank you for the help everyone !
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