Different hash when using risers?

Odd issue. I’ve switched some of my 1080 TIs into a rig and I’ve noticed that for some reason just by using PCIE risers I get less hash then before. I’ve got 2 slightly different models of riser and they both do the same thing and I tested it in my other system and I go from 700~ with 80 TDP 150 core and 300 mem down to about 600-630. I’ve noticed my card crashing a lot in the other system too, not sure why it’d OC fine before but now its on a riser its a problem. 2 odd issues. The risers are the typical 6 pin to SATA risers. Only 1 card in the machine on a dedicated SATA line.

Each riser “should” have a code on it, for example 006C - the higher the number, generally the better and newer the riser is - with better components and technology.

I would go for 006C at a minimum - anything older has caused me problems/instability in the past. But overall, having a riser shouldn’t change the hash rate…

Appreciate the help! I thought I was going crazy for a bit.

So far I did try another riser but its from the same box. I ordered a box of the molex ones as I’ve heard they’re better and less cabling anyway, can return these 6 pin to Amazon.

Trying Windows 10 before I replace the mobo. This mobo is from a system I had where the PSU blew (unrelated to mining) and its acted strange since. The onboard sound is toasted and the board has been around for years. For the sake of $170 I should get something I can trust.

The ASRock H81 BTC Pro 2 is a good board - much cheaper than $170 on Amazon…

I’ll see if my local computer store has it in stock. Said 170 as I’d need a new CPU too. Old board is an LGA1366 I think…

I found the issue. One of those lovely twofold issues that makes it super hard to track down. #1 is I’ve got a bad riser. It goes from 85-97% usage over and over again. That must’ve been the one I tried on my main desktop that works beautifully. Thus it gave weird results like the new rig I’m building. #2 is the CPU is at 90C in the new rig. No idea why. Added new thermal paste yesterday as it was overheating the moment I turned it on. Just getting a new board at this point. No trust in this one.

Isn’t the H81 a super old board? Wouldn’t you go with a B250 or B350 board?

Holy 19 slots lol. Im mostly focusing on getting a number of 5-6 card systems growing but will smash em onto a board like that one day.

H81 btc pro R2.0 cost here in europe about 60-70 EU (70-85 us) and still is a “hot” item…risers v007 with sata connection cost 33 eu 10pcs (38 usd) from Ali and they works fine for me. I prefer rigs up to max 8 cards. GTX 1070’s do around 475Sol/s each with smos.

Did you ever get this figured out? I’m having the same issue with my 1080ti and an Asus Prime z270-a mobo.

The card gives me 700-725 sol in the pci slot. But once i connect it to a riser i lose hash. and the hash fluctuates wildly. I try 3 different risers. I use these mobo and risers in my AMD rigs with no issues.
I have also tried molex, or 6 pin to the riser. Just to eliminate any power issue i ran 3 pci cables to the card.
1 to the riser (6pin) 2 to the 1080ti (8+6)
Im out of ideas and have 2 more cards on their way in the mail. i want to get this resolved asap

I have been running this card stable for over 2 months in my pc with the same settings.

Since this post I’ve had a bevy of issues but I’ve got most of them solved.

First is that for some reason multiple cards operate differently then a single. I’ve had a card pushing +160MHZ core in my main comp connected to the mobo directly and I put it into a rig and it won’t stability go past 110. Just the way it is.

I had 3 big issues that I’ve solved. One is I was using Auto PCIE selection. I found going to Gen2 I got better performance and the cards were more stable. By stable I mean watching in Afterburner the usage would be from 85-100% over and over again. I also discovered that using Windows7 was hurting me as it wasn’t playing nicely with the processor as it was designed for Windows10. I went to 10 and the cards all pretty much run at 98-99% constantly.

I also had a strange driver issue. Clean reinstall helped the usage be more stable. I had the same issues across 3 6 card rigs in different ways but it came down to those 3 things for the most part. I’m running 19 1080TIs and they’re all stable and running great.

hmm ok. already at Gen2. and on l Win10
what settings and sol are you using for the 1080ti?

Im at
85% TDP (212W)
1822 MHz. Core clock
5300 MHz Mem clock

700-725 sol on the mobo.

it drops to under 650 on riser.

What 1080 do you have? I’ve got 12 Evga Blacks and they’re 710ish at 80%. They did about 740 on the board. Now my gigabytes with blowers do about 660 but they’re reference cards.

Sometimes you need to modify the mobo bios. Look on YouTube, or just go in and look through all the settings. Some let you increase the bandwidth to a higher setting with the pcie lanes. Some have a setting for more than 4 cards. Also red alert on any 1080ti riser that is connected to a sata cable, especially with a 6 pin or Molex adapter. That card can draw the full 75w from riser. Sata is rated for 54w max. Huge fire hazard going from 6pin or Molex with an adapter to sata. Unless you are way under volting and you have a tester to show how much the riser is pulling. Most people don’t have that type of equipment. 1080ti should always be powered directly 6 pin or Molex from the riser to the psu. Don’t have enough cables? Order one more via cablemod.com