Author

Topic: Strange drop in hashrate (1 gpu) (Read 1082 times)

newbie
Activity: 24
Merit: 0
June 25, 2017, 02:06:17 AM
#5
It's now back to normal... tho I don't know how exactly I fixed it...

Here's what I did, in case somebody are facing same issue.
1.) Take 2-3 cards off, remove the riser.
2.) Plug all of them back (new order) so I switched the trouble one in new slot
3.) Reinstall driver
4.) Rollback to stock setting
5.) I'm now using 3.3b instead of 3.4 for the EWBF Miner.

Constant speed only 55-61c atm, will continue watching!
full member
Activity: 214
Merit: 100
June 24, 2017, 08:57:37 PM
#4
sounds like you are using Windows.  If you are, download GPU-Z then open the program.  On the Sensors Tab looks towards the bottom and you will see an entry named:  PerfCap Reason.  In the next column it will list the reason, for me it's power as I'm only at 85% TDP.  But when I raise my percentage higher than other reasons show.  I'd use GPU-Z to compare the card with the slower hash to the values of the normal cards and see if it will give you a hint to the issue.
newbie
Activity: 24
Merit: 0
June 24, 2017, 03:27:18 PM
#3
maybe the rig can't handle 6 gpu, the motherboard maybe, or the gpu is throttling? can you check if yes with the power consumption or the usage?

I'd like to assume it that way, but I think this sometimes happens randomly?

If the rig can't handle gpu, it should happen to some other cards when I switching the riser or pci slot right? I will try that asap.

What are possible causes for GPU throttling? probably the temp? Now every card is running below 60c. Also the last time this happened to my old rig the cards were all same and brand new, the overclocking was also the same as well as all the stat reported same temperature, only that a single gpu didn't fully perform Sad

I reinstalled the driver, seems like it is not fixed.
sr. member
Activity: 406
Merit: 250
June 24, 2017, 02:35:09 PM
#2
maybe the rig can't handle 6 gpu, the motherboard maybe, or the gpu is throttling? can you check if yes with the power consumption or the usage?
newbie
Activity: 24
Merit: 0
June 24, 2017, 02:26:22 PM
#1
I think I've noticed a significant drop in 1 gpu hashrate during mining. This is the 2nd time I notice this happening, looking forward to understand the real cause and solution if possible.

This rig is currently now 6-gpu rig, it was 5 before, every of them run smoothly and after I inserted an additional GTX 970 yesterday the result was satisfactory at first! Around 270 sols/s for 970 using EFWB Zec miner.

After a restart the hashrate of this card strangely drop to 220 and never goes up again. I can't figure this out? Have anyone experienced this before and what is your solution?

PS. This also happened with my old rig of 4 gpus (different set of cards) however I didn't fix it as I think it might be a glitch, but this time I think I'll need to get it fixed, otherwise the performance per watt will be real bad for 970 that draws huge amount of power.

Thanks
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