4 ms·

It would take some serious "skill" to plug in a PCI device and not have it grounded. There are at least a half dozen ground pins in the interface itself. I don'

It would take some serious "skill" to plug in a PCI device and not have it grounded. There are at least a half dozen ground pins in the interface itself. I don't see what tying the GPU to ground again is meant to accomplish - it's not adding any shielding to the system as a whole. DC continuity is not a good measure of impedance as you move into higher frequency RF signals. Wires that look like low-impedance connections can easily become accidental antennas.

dogma1138 8y ago
It’s not since for PC there is ground to earth through the case since the (power) ground through the power supply is often interrupted and does not lead to true earth.
- yjftsjthsd-h 8y ago
  Why? The power supply is a metal box in contact with the metal case; it is really not connected internally?
  - oneweekwonder 8y ago
    As parent said "painted metal". In this video showing how pc cases is made[0]. They mention they automate the powder coating of paint. So the external case should be well insulated. [0]: https://www.youtube.com/watch?v=XX2i-QhPCD0 https://www.youtube.com/watch?v=XX2i-QhPCD0
    - Animats 8y ago
      As parent said "painted metal". Look at the pictures in the original article. He built his open racks from multiple painted metal parts. The metal parts probably don't provide a solid path to ground. Connecting the ground stake to a big piece of metal that's not grounded adds an antenna to the thing and makes emissions worse. Easy to fix. Use a Dremel tool and grind off the paint where the stake is screwed into the metal rail. Use jumper wires (properly, green ones) and crimped screw lugs to connect the rails together. Connect those to something that has a grounded case. Check with an ohmmeter to see that there's continuity between the metal cooling plate on the GPU and the ground pin of what plugs into the wall. Should be less than 1 ohm. Use an outlet tester to make sure your wall outlet has a valid ground pin. Now most of your RF hash gets clamped by the tie to ground.
  - dogma1138 8y ago
    It is but not through the DC “ground” trough the power cables but through the motherboard via the case and via pin 18 and 19 on the main ATX which should lead to earth but not always. If the motherboard is not connected via metal stems and screws through the holes with an earth ground plane it won’t be grounded this is why there are either solder dots or a copper ring around the screwholes in the motherboard and why you should not use plastic standoffs unless they are explicitly specified and then often if you use metal standoffs you might screw something up. For mining you essentially connect cards via PCIe raisers which often use a USB 3.0 cable and the card is connected to 12v rails which may or may now lead to earth and often they won’t. It’s really not that hard to screw it up.

dogma1138 8y ago

It’s not since for PC there is ground to earth through the case since the (power) ground through the power supply is often interrupted and does not lead to true earth.

yjftsjthsd-h 8y ago
Why? The power supply is a metal box in contact with the metal case; it is really not connected internally?
- oneweekwonder 8y ago
  As parent said "painted metal". In this video showing how pc cases is made[0]. They mention they automate the powder coating of paint. So the external case should be well insulated. [0]: https://www.youtube.com/watch?v=XX2i-QhPCD0 https://www.youtube.com/watch?v=XX2i-QhPCD0
  - Animats 8y ago
    As parent said "painted metal". Look at the pictures in the original article. He built his open racks from multiple painted metal parts. The metal parts probably don't provide a solid path to ground. Connecting the ground stake to a big piece of metal that's not grounded adds an antenna to the thing and makes emissions worse. Easy to fix. Use a Dremel tool and grind off the paint where the stake is screwed into the metal rail. Use jumper wires (properly, green ones) and crimped screw lugs to connect the rails together. Connect those to something that has a grounded case. Check with an ohmmeter to see that there's continuity between the metal cooling plate on the GPU and the ground pin of what plugs into the wall. Should be less than 1 ohm. Use an outlet tester to make sure your wall outlet has a valid ground pin. Now most of your RF hash gets clamped by the tie to ground.
- dogma1138 8y ago
  It is but not through the DC “ground” trough the power cables but through the motherboard via the case and via pin 18 and 19 on the main ATX which should lead to earth but not always. If the motherboard is not connected via metal stems and screws through the holes with an earth ground plane it won’t be grounded this is why there are either solder dots or a copper ring around the screwholes in the motherboard and why you should not use plastic standoffs unless they are explicitly specified and then often if you use metal standoffs you might screw something up. For mining you essentially connect cards via PCIe raisers which often use a USB 3.0 cable and the card is connected to 12v rails which may or may now lead to earth and often they won’t. It’s really not that hard to screw it up.