[ANN] US/North American Bitfury sales NEW STOCK ***NOW SHIPPING***

[Asinine]

the hashrate fluctuates a lot, so most 'drops' are just periods of low luck, rather than a change to the amount of hardware connected to the network. however, its likely the drop in value may be enough to dissuade any remaining fpga and GPU miners.

it may be possible too that some early adopters (gen 1 where >7GH/W) are limited from adding newer machines due to having BTC invested or already using several kW of power

Looking at bitcoinwisdom, it's starting to look like a bit of a trend rather than the usual hick-ups.  It's not like it's anything major at this point, just an oddity.  It would be nice to eak out another two weeks of about 0.01 BTC/day or better per card.  But, it's too early for that...

[allinvain]

I suspect they're upgrading their mining farm to something better and they're offloading the old gen stuff on all you dear customers. Bet you anything these are used or have been used in their mining farm.

No, these are the same boards we're using. 

Ah, ok. Well, it's fun to speculate once in a while. I hope you guys lower the price just a tiny bit more so I can grab a few v1.2 h-cards and _not_ lose money on them.

[Syke]

30% difficulty increase now in effect. I suggest the prices drop 30%.

[Keefe]

Old-gen stuff would be on V1 and V2 m-boards at this point.  The photos show what appears to be a new generation of PCIe card with exposed metal for thermal dissipation on the back.  I just think it makes them more money to sell rather than deploy at the moment.  That makes 3 different versions of PCIe cards that I am aware of.   The somewhat problematic ones with the grey-metallic coil pack, the pulse coil ones, and now this.

You are correct.  These new ones with the metal backing can fit and work in both the V2 and V3 M-boards.

Don't V3 M-boards have completely different slots than V2 and V1 M-boards?

[bobcaticus]

Old-gen stuff would be on V1 and V2 m-boards at this point.  The photos show what appears to be a new generation of PCIe card with exposed metal for thermal dissipation on the back.  I just think it makes them more money to sell rather than deploy at the moment.  That makes 3 different versions of PCIe cards that I am aware of.   The somewhat problematic ones with the grey-metallic coil pack, the pulse coil ones, and now this.

You are correct.  These new ones with the metal backing can fit and work in both the V2 and V3 M-boards.

Don't V3 M-boards have completely different slots than V2 and V1 M-boards?

The V2 H-boards had the slot cut added because people were putting the V1 boards in backwards in the V1 M-boards and frying the whole units.  The V2 and the V3 tabs are the same.  V3s use a different SD image and the M-boards have a couple tweaks added to them to make the system run more smoothly. 

[allinvain]

Indeed I can confirm that V3 boards are the most stable I've had. V1.2 are iffy. They're too flaky for my liking and require constant maintenance, but that's the price we pay for getting in early I guess.

[Soros Shorts]

ANOTHER FIRE HAZARD WARNING:

One of my 16-card October kits that came calibrated at 0.865 V started to melt/burn at the PSU. It is a Seasonic Platinum 860W connected to the M-board using the standard 2 PCI-e power connector setup. It had been running fine for over a month at 620W and then suddenly I started smelling smoke coming from part where the modular connectors plug into the PSU.

Fortunately, it happened while I was in the room so I managed to shut it down before anything serious happened. 2 PCI-e modular ports on the PSU were melted and no longer usable. However, I managed to repair the rig using the other unused PSU ports. I now have it running with 2 x PCI-e cables AND a jerry rigged CPU 12V cable going to the ring terminals.

I also brought the voltage for all the cards down to 0.83 V. The loss in GH/s was minimal (the setup runs at 540 GH/s now) but I sleep much better.

Note: This is not the first time I've had a high-end modular PSU burn out at the modular connectors.

[allinvain]

ANOTHER FIRE HAZARD WARNING:

One of my 16-card October kits that came calibrated at 0.865 V started to melt/burn at the PSU. It is a Seasonic Platinum 860W connected to the M-board using the standard 2 PCI-e power connector setup. It had been running fine for over a month at 620W and then suddenly I started smelling smoke coming from part where the modular connectors plug into the PSU.

Fortunately, it happened while I was in the room so I managed to shut it down before anything serious happened. 2 PCI-e modular ports on the PSU were melted and no longer usable. However, I managed to repair the rig using the other unused PSU ports. I now have it running with 2 x PCI-e cables AND a jerry rigged CPU 12V cable going to the ring terminals.

I also brought the voltage for all the cards down to 0.83 V. The loss in GH/s was minimal (the setup runs at 540 GH/s now) but I sleep much better.

Note: This is not the first time I've had a high-end modular PSU burn out at the modular connectors.

Well, c'mon guys, what do you expect. These systems were not engineered properly with that much power draw in mind. 620 watts is far too much to draw from just two 6pin pcie connectors for extended period of time. It will run fine for a short while as I've experienced when I melted my PSU's module plugs too. I now have the rig tuned to 500 GH and a power draw of 475watts. I'm not going any further than that as I don't feel like melting every damn PSU I have. This is with a V2 m-board which does NOT have the rig connectors so I can't use that to spread the load a bit.

If you can, measure amperage on each of the PCIE 6pin cables and see how much is going and make sure you do not exceed the rated maximum for the wire gauge your psu uses.

I've said this before, but I will say it again; I am shocked that they did not engineer the m-board with 3 or 4 separate 6pin PCIE connectors.

[twmz]

ANOTHER FIRE HAZARD WARNING:
...

I also brought the voltage for all the cards down to 0.83 V. The loss in GH/s was minimal (the setup runs at 540 GH/s now) but I sleep much better.

About how much of a turn is needed to make a reasonable reduction in voltage?  A quarter turn counter-clockwise?  More?  Less?  I do not have a meter to measure the voltage directly, but at this point, both because of stability and risk of fire, I'm inclined to start making blind voltage reductions. I just need some indication of how sensitive the trimpot is so I know if I should make tiny turns/adjustments or larger turns/adjustments.

I do have a kill-a-watt, so can measure the power draw at the wall before and after making a change to see how much of a change I made...

[Keefe]

I think the V2 M-boards have empty positions for screw blocks. I'd get some PCIe cable extenders from eBay, cut off the male end, and solder the wires into those holes. That would add two more sockets so you can power the rig with four power cables.

[Doff]

I think the V2 M-boards have empty positions for screw blocks. I'd get some PCIe cable extenders from eBay, cut off the male end, and solder the wires into those holes. That would add two more sockets so you can power the rig with four power cables.

Id love to see this in the guide so I can do this to my rig. It sounds easy enough but I have questions on how to do this correctly and would like to see some pictures of what it looks like.

Also do you have to solder them? I thought you could just attach them to some ring connectors then the connectors to the board?

[Keefe]

I think the V2 M-boards have empty positions for screw blocks. I'd get some PCIe cable extenders from eBay, cut off the male end, and solder the wires into those holes. That would add two more sockets so you can power the rig with four power cables.

http://www.ebay.com/itm/251382532478

I don't know if the wires in that cable are too thick for those board holes.

[Doff]

My M-board has the screw blocks on it, looks like I just need to remove the screw real quick and attach the ring connectors. What I don't know is what wires do I then place in the ring connectors once I cut the extender. I realize one should contain the ground wires and the other power but not being very savvy when it comes to wiring period I'm not sure what goes where.

[Keefe]

My M-board has the screw blocks on it, looks like I just need to remove the screw real quick and attach the ring connectors. What I don't know is what wires do I then place in the ring connectors once I cut the extender. I realize one should contain the ground wires and the other power but not being very savvy when it comes to wiring period I'm not sure what goes where.

On a 6-pin PCIe connector, the three wires on the clip side are GND and the other three are +12V.

[Doff]

That looks easy enough, thank you Keefe

[Asinine]

Some of the (I believe newer) V3 boards (there are more than one type of V3 m-board) have the screw down posts as well as pcie power connectors.  The one I have has those loose pci-e H-Card slots people where complaining about that result in flapping cards.  The other one is missing the posts, but the pci-e slots are stiffer.

Note:  I am not talking about the V1 or V2 that have the short ISA-like card slot

[bobcaticus]

I snapped a quick shot of a V3 M-board.  (Be gentle on my photoshop skills - I had a couple minutes to snap a photo while the relatives are cooking in the other room) You'll see the PCI-E plugs on the left, and the screwdowns on the right.  The V2 has technically the same layout.  V1 is screwdown only.

From what I have been told, you can plug into either/or.  Some people have both plugged in, but either should pull enough power from the PSU.

[Keefe]

I snapped a quick shot of a V3 M-board.  (Be gentle on my photoshop skills - I had a couple minutes to snap a photo while the relatives are cooking in the other room) You'll see the PCI-E plugs on the left, and the screwdowns on the right.  The V2 has technically the same layout.  V1 is screwdown only.

From what I have been told, you can plug into either/or.  Some people have both plugged in, but either should pull enough power from the PSU.

The concern isn't getting enough power to the rig, it's avoiding overheating of the connectors, since they weren't designed for 320W+ on a single cable.

[twmz]

Ok, so I borrowed a volt meter from a friend to reduce the overclocking on my rig, but I have a question for those that have made adjustments (this is a v3 rig, so has the v2.2 H-boards).

Do you adjust the trimpot while the rig is powered up but not mining?  Or do you power everything down, make an guess at how far to adjust the trimpot, then power it back on to measure and see if you guessed right, and then repeat?

[Keefe]

Ok, so I borrowed a volt meter from a friend to reduce the overclocking on my rig, but I have a question for those that have made adjustments (this is a v3 rig, so has the v2.2 H-boards).

Do you adjust the trimpot while the rig is powered up but not mining?  Or do you power everything down, make an guess at how far to adjust the trimpot, then power it back on to measure and see if you guessed right, and then repeat?

I always adjust voltage (either with a pencil on the older boards or with the trimpot on newer ones) while powered but not hashing. It might be a bad idea, but it hasn't caused me any problems.