Several months back I got back into mining, in particular Ethereum. I already had an ASRock H81 BTC Pro, Pentium G3220 and spare 4GB of RAM from a couple of years ago. The plan was to put together a 6 x 290x rig using five USB powered risers and one 16x non-powered ribbon riser and EVGA 1300w G2 PSU. I had previously mined with five GFX cards on this motherboard using USB risers but as I sold the risers last year I needed to buy more, so I did.
With one GFX card attached to the 16x slot via the 16x ribbon the PC would boot and mine in either Windows 10 or using
https://simplemining.net Ubuntu 14 based OS. Good start. Next step, test with two cards.
And this is where the problems started..... The ASRock struggled to detect any GFX cards plugged in via a powered USB riser. I tried every combination of riser, GFX card, PCIe slot and multiple BIOS settings and I think in the end the best I could do was to get it to mine with two cards in SimpleMining OS, but only if the second card was plugged in the top 1x PCIe slot. Windows 10 however was totally stuck with just one card. If the second card was plugged into the top slot I could maybe get it to boot to Windows, but the second card would never be functioning either because Windows had "disabled it as a problem had been detected" or it just wouldn't appear in device manager at all. When trying the other slots most of the time it would start booting and then I'd get a BSOD with "thread stuck in device driver".
Naturally, I thought the ASRock board was faulty, even though I tried a wireless network card in every slot and Windows 10 recognised that every time! I had a spare ASUS Z97-A lying around, and although it only had five PCIe slots I thought I'd give it a go. Initially, I had all the same problems as with the ASRock board. Until I found a BIOS setting which allowed me to set the PCIe mode to GEN 1. This is absolutely the light and day setting it seems. With all the 1x PCIe slots forced into GEN 1 mode I can now mine on that rig with five GFX cards and have done for weeks. Purely for testing only and proof that this setting is the magic trick, even today I tried it in AUTO and GEN 2 mode and every time Windows 10 fails to boots and I get a BSOD with "thread stuck in device driver".
So last week I decided I wanted to build another mining rig. I bought another batch of powered USB risers from the same place as before, six RX480, an EVGA 1600 T2 PSU, 2x2GB Curcial DDR3 1600 and Celeron G1840. I thought I'd give the ASRock H81 BTC Pro board another try. Had all the same issues. After checking and double checking, it appears that on the ASRock board there is no BIOS option to force the PCIe generation on the 1x slots, only the 16x slot. My main PC running an ARock Z97 Extreme 4 also does not have an option to force PCIe generation on the 1x slots, again only the 16x slots. for now to make use of their power efficiencies I have placed all the RX480s in other rigs and pulled out 290x.
Next up, I went on Ebay and bought an MSI Z97 Gaming 5 as they have 7 PCIe slots. Three 16x and four 1x. I started putting that together last night with six 290x, Celeron G1840, 4GB and EVGA 1600w PSU. With one card on the top 16x slot with a 16x ribbon all was well in Windows and SimpleMining OS. I then added a second card with a powered USB riser onto the second 16x slot. The PC wouldn't even POST. So I removed that second GFX card and went into the BIOS and found that there are three PCIe generation options, one for each 16x slot. I forced them all to GEN 1, plugged the second GFX card back in and it boots to Windows 10 and starts mining on both cards. I then plugged in a third card, via USB riser to the third 16x slot. It boots to Windows and/or SimpleMining.net and I'm mining on three cards, I'm starting to rub my hands with joy and get excited. However, then I hit a stumbling block. The only slots left are 1x slots and if I used any of them to plug in a fourth GFX card Windows fails to boot and I get a BSOD saying, you've guessed it, "thread stuck in device driver". Like the ASRock boards there doesn't appear to be a BIOS option to force PCIe GEN 1 on the 1x slots and I'm certain that this is the same problem all over again. Incidentally, if I put the fourth card in the top 1x slot I can get mining working on four cards with SimpleMining.net OS only. So for now i'm doing that as four is better than three(Limit with Windows) or nothing
So, some questions :-
- Clearly, lots of people have used the H81 BTC Pro with USB powered risers and it works, even I did in the past. So what the hell am I doing wrong now?
- Does anyone else use an MSI Z97 Gaming 5 for mining, with USB powered risers and more than four GFX cards and it works in Windows?
- Has anyone else had this problem of having to force GEN1 on all PCIe 1x slots for mining to work?
- If so, do you know of a way of forcing GEN 1 when BIOS options don't exist?
- Is there another fix for "thread stuck in device driver"?
- Does anyone agree with my gut feeling that the problem here is the USB risers and that i've bought two dodgy batches that just won't work in PCIe GEN 2 mode?
- If so, what shall I look out for when buying the next batch?
- Currently I have Ver 003 riser boards, is this even meaningful?
Thanks for reading, and thanks in advance for any help.
EDIT: I'm just about to test an RX480 on a USB powered riser on my ASRock Z97 Extreme 4. Expecting, "Thread stuck in device driver".....
EDIT: All motherboards have the latest BIOS installed. All three boards have been used with fresh Windows 10 installs with latest drivers at the time, generally Cat 16.8 or 16.9.