Using an ASRock H81 Pro BTC board? Beware!!

hasherhasher Member Posts: 642 ✭✭✭
edited June 2016 in Mining
Walked into my mining room today and smelt something burning badly. I immediately shut down my farm and checked each rig. After 25 minutes, I found where the smell was coming from…







This rig is running 6 x Sapphire 390 Nitros, with two Corsair AX1200i PSUs + Add2PSU, an H81 Pro BTC mainboard, and unpowered riser cables. Many people in the past said if you add additional power to this particular mainboard via the molex connectors on the main board, you won't need to use powered risers. Well, this is what happens after a few weeks of mining without the powered risers…

Maybe if I was using less powerful cards such as the 280X/380X, the unpowered riser setup would work okay, but I guess the 390 just demands too much power. Now I have a PSU that has melted connectors on both sides, the connector that connects the additional molex power has also melted, and the ATX power connecter on the main board has melted. One rig down and a valuable ~200MH of hashing power gone to waste.

One PSU and one main board now have to go for RMA. Not even sure if they will accept it when they see all the melted connectors. FML. I'm considering this a lucky catch - lucky in the sense that nothing went on fire!

Lesson learnt for today? - ALWAYS use powered risers, regardless of whether they say its needed or not.

Comments

  • adasebadaseb Member Posts: 1,043 ✭✭✭
    Yeah you gotta use powered cut risers everytime. Those molex connectors can't supply the extra power to 6 GPUs.

    I am surprised that your PCIe connected melted however.
  • hasherhasher Member Posts: 642 ✭✭✭
    FYI, I had 3 GPUs connected to each PSU, so I don't think the main PSU was overworking itself.. 1200W should be plenty for 3x390, SSD, and mainboard power. But yes, everything is melted. The sockets on the affected PSU won't fit other non-damaged PCIe cables now because there's bits of melted plastic that has moulded themselves to the inside of the holes. What a fun evening i've had :( Will have to buy a new mainboard tomorrow to get this rig back up and running ASAP. Lucky I have a spare unopened AX1200i PSU sitting in the corner on standby. PSU #2 seems to be okay.
  • big_MIKEbig_MIKE Member Posts: 84
    I ran many different 6 card rigs years ago. 280x, 290, & 290x rigs all used dual power supplies and unpowered ribbon risers on H81 Pro BTC. Even my six card 280x and 370 rigs mining now are not using powered risers on H81 Pro BTC board. Never had any issues. So maybe powered risers might be what most people use, I just wanted to point out that unpowered risers are not guaranteed to start fires just because some people have experienced it. My old rigs ran for like 2-3 years 24/7. My ethereum rigs also run 24/7.
  • o0ragman0oo0ragman0o Member, Moderator Posts: 1,291 mod
    @hasher Wow, lucky catch. It would seem to me though that it shorted somewhere rather than the GPU's pulling that much current on a previously stable rig. Have you had a look for damage on the Motherboard itself?
  • workwork Member Posts: 2,084 ✭✭✭✭
    Definitely seen this before. I definitely stick with powered risers and don't pull any power from the motherboard just for this reason. Drawing up to 75 W * 6 = 450W thru the motherboard is just crazy.

    My bet is some kinda weird feedback between the 2 PSUs here tho. It seems likely power was actually running back down from the GPU to the mainboard.
  • hvalentinohvalentino Member Posts: 105
    I always plug the power riser... on all of them
  • o0ragman0oo0ragman0o Member, Moderator Posts: 1,291 mod
    @work that pin 10 on the molex 24 pin is 12V, the the mobo was definitely sinking current rather than shunting it.

    @hasher, Unpowered risers, so you're using ribbons right? I had one short in the socket when I knocked it once, so maybe something to look at
  • hasherhasher Member Posts: 642 ✭✭✭
    @o0ragman0o Yes, this particular rig was running ribbons, all unpowered 1x to 16x. I've just had a shipment of 50 powered USB risers arrive from Hong Kong, so I will use them from now on. Wondering if I should change all my other ribbon risers on my other rigs to the USB ones?

    Today I bought a Gigabyte GA-990FXA-UD3 R5 mainboard with an AMD CPU. I know this mainboard is probably overkill for mining, but I have the same mainboard running a 6 x 380X rig, and its been running flawlessly from day one (not one single crash or hiccup at all) so I will reinstall Windows (since this new Gigabyte board and the H81 Pro BTC use different chipsets) and run the 390s on it. Fingers crossed everything goes according to plan. This Gigabyte mainboard is double the cost of an H81, but it looks like a quality board, and i'd rather pay more for something that will be more reliable.
  • citronickcitronick Member Posts: 110
    those flat ribbon risers were popular during the LTC days and powering older cards should do just fine.... however 390 is a different beast altogether, it draw a lot more more to deliver those 30++MHs mining ETH. The USB3 powered risers are much more reliable and having molex powered and risers powered you should not have any issues with newer cards like 390s with the H81 motherboard - it's cheap and good, and it works all the time.
  • workwork Member Posts: 2,084 ✭✭✭✭
    It shouldn't matter what card tho... PCI-E spec says a device shouldn't draw more then 75watts from the bus. That said, I never liked the idea of 75watts over a ribbon cable.
  • LogicaluserLogicaluser Member Posts: 214 ✭✭
    @work I recall seeing some measurements a few years back showing mining cards using very little PCI-E slot power, IIRC it was like 5-20w per card with substantial differences from one series/generation to the next.

    But... that would have been back when 7970 was flagship
  • XylocaineXylocaine Member Posts: 57
    @hasher I have no issues running 6x290 (overclocked) rigs with non-powered risers on that boards. But I connected PSUs (different models) with that thing:

    On my newest rigs I have something like add2psu, so I use 1 PSU and 3 non-powered risers for mobo + 3 cards, and other PSU and 3 powered risers for other 3 cards.

    Maybe 390 draw more power form PCI-E than 290 or some power fluctuations between PSUs may be the cause.
  • mista66mista66 Member Posts: 117
    hasher said:



    Lesson learnt for today? - ALWAYS use powered risers, regardless of whether they say its needed or not.

    Fwiw same kinda thing can happen with powered risers. they easily short, the molex on the riser boards (with just a thin piece of foam) takes a lot of weight from the GPU's and with those things resting against a metal frame, expect a short!

    @hasher Wow, lucky catch. It would seem to me though that it shorted somewhere rather than the GPU's pulling that much current on a previously stable rig. Have you had a look for damage on the Motherboard itself?

    indeed lucky catch

  • hasherhasher Member Posts: 642 ✭✭✭
    Never really considered the issue of weight.. the GPUs are fastened to the aluminium frame quite well, so i'm assuming most of the weight is being supported by the screws. Although I don't think that would be an issue about shorting @mista66

    I still have another identical rig running without powered risers, and it still seems to be running okay, so maybe that PSU just had problems, since I have been using it since the LTC mining days.
  • mista66mista66 Member Posts: 117
    @hasher try pressing the foam on the riser board see if any the pins ar piercing threw...

    I've added a thicker layer of the foam to insulate the board where it rests against the frame
  • adlruizadlruiz Member Posts: 11
    hasher said:

    @o0ragman0o Yes, this particular rig was running ribbons, all unpowered 1x to 16x. I've just had a shipment of 50 powered USB risers arrive from Hong Kong, so I will use them from now on. Wondering if I should change all my other ribbon risers on my other rigs to the USB ones?

    Today I bought a Gigabyte GA-990FXA-UD3 R5 mainboard with an AMD CPU. I know this mainboard is probably overkill for mining, but I have the same mainboard running a 6 x 380X rig, and its been running flawlessly from day one (not one single crash or hiccup at all) so I will reinstall Windows (since this new Gigabyte board and the H81 Pro BTC use different chipsets) and run the 390s on it. Fingers crossed everything goes according to plan. This Gigabyte mainboard is double the cost of an H81, but it looks like a quality board, and i'd rather pay more for something that will be more reliable.

    what driver are you using? i try 6 rx470 with the lastest driver and the rig boot but when windows is starting it just reboot again and again, but when i leave 5 gpu connected windows boot normal
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