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Alternate cryptocurrencies => Mining (Altcoins) => Topic started by: jbass350z on February 13, 2014, 02:33:38 PM



Title: High reject rate for middlecoin?
Post by: jbass350z on February 13, 2014, 02:33:38 PM
I've read that other people have higher reject rates on middlecoin, but this seems higher than most. Are there any settings I can change to lower the reject rate?

https://i.imgur.com/b5sEDUc.png


Title: Re: High reject rate for middlecoin?
Post by: Wipeout2097 on February 13, 2014, 03:01:01 PM
What is your CPU, MB, cards, OS, software running and miner config?

Use intensity 18 if gpu-threads=1

What's your ping to useast?

Then since these are coin-hopping pools, those 2 screenshots don't prove much. High reject rate can be coin dependent.


Title: Re: High reject rate for middlecoin?
Post by: jbass350z on February 13, 2014, 03:28:54 PM
CPU: Sempron 145
MOBO: Gigabyte GA-990FXA-UD3
GPUs: Gigabyte and Asus 270s
BAMT 1.3

Config:

Code:
"intensity" : "19",
"vectors" : "1",
"worksize" : "256",
"kernel" : "scrypt",
"lookup-gap" : "2",
"auto-fan" : true,
"temp-cutoff" : "85",
"temp-overheat" : "80",
"temp-target" : "70",
"thread-concurrency" : "10239, 21568, 21568, 21568, 10239, 10239",
"api-port" : "4028",
"expiry" : "120",
"gpu-dyninterval" : "7",
"gpu-platform" : "0",
"gpu-threads" : "1",
"gpu-engine" : "1120, 1025, 1100, 1100, 1120, 1125",
"gpu-memclock" : "1440, 1250, 1250, 1250, 1440, 1450",
"gpu-powertune" : "20",
"log" : "5",
"no-pool-disable" : true,
"queue" : "1",
"scan-time" : "60",
"scrypt" : true,
"shares" : "0",
"sharethreads" : "32",
"kernel-path" : "/usr/local/bin"
}


Title: Re: High reject rate for middlecoin?
Post by: crazyates on February 13, 2014, 08:23:53 PM
On Middlecoin, our 280x rigs are usually ~1-3%, and our 290 rig is ~5-8%.

The 280xs run 2 threads at lower intensity, so I think it helps with the rejects. Any scenario where you're running one thread at high intensity will inherently have higher rejects, but usually the difference is tiny.

The problem is more pronounced with Middlecoin, because of the fact that you're switching coins so often. Many times, you may require new work every couple of seconds. You can tweak how often s/cgminer checks for new work with the "scan-time", "expiry", and "queue" configs.

See Con's original explanation for those settings:
Quote
--expiry|-E <arg>   Upper bound on how many seconds after getting work we consider a share from it stale (default: 120)
--scan-time|-s <arg> Upper bound on time spent scanning current work, in seconds (default: 60)
--queue|-Q <arg>    Minimum number of work items to have queued (0 - 10) (default: 1)

So your miner gets work from your pool. CGMiner thinks that work is valid for another 120 seconds (2 minutes), but will only spend 60 seconds working on it. After that, it moves onto a new set of work. The queue says we'll keep one extra set of work on backup, at all times.

Remember that these 120/60/1 defaults are for Bitcoin, which has a 10 minute block period, and the difficulty recalculates every ~12-14 days. Many alt-coins will have MUCH shorter block times, and recalculate the diff VERY quickly. If cgminer is working on a block for 60 seconds, and thinks that those shares are valid for 120 seconds, when in reality the new alt-coin network is finding a new block every 10 seconds, a lot of what you do is going to be invalid.

We can use this info to edit those parameters. We can set a lower value for all of those, so it's getting newer, valid work more often, and you're not wasting time hashing a block that's already been found. We use -E 30 -s 15 -Q 0, which works well on our 280x rigs, but not on our 290 rigs. I haven't gotten around to changing our 290 rig, but for you, I would try -E 10 -s 5 -Q 0, and see if that lowers your rejects.

TL:DR use this newer config:

Code:
"intensity" : "19",
"vectors" : "1",
"worksize" : "256",
"kernel" : "scrypt",
"lookup-gap" : "2",
"auto-fan" : true,
"temp-cutoff" : "85",
"temp-overheat" : "80",
"temp-target" : "70",
"thread-concurrency" : "10239, 21568, 21568, 21568, 10239, 10239",
"api-port" : "4028",
"gpu-dyninterval" : "7",
"gpu-platform" : "0",
"gpu-threads" : "1",
"gpu-engine" : "1120, 1025, 1100, 1100, 1120, 1125",
"gpu-memclock" : "1440, 1250, 1250, 1250, 1440, 1450",
"gpu-powertune" : "20",
"log" : "5",
"no-pool-disable" : true,
"queue" : "0",
"scan-time" : "5",
"expiry" : "10",
"scrypt" : true,
"kernel-path" : "/usr/local/bin"
}


Title: Re: High reject rate for middlecoin?
Post by: atp1916 on February 13, 2014, 08:53:18 PM
Quote
Remember that these 120/60/1 defaults are for Bitcoin, which has a 10 minute block period, and the difficulty recalculates every ~12-14 days. Many alt-coins will have MUCH shorter block times, and recalculate the diff VERY quickly. If cgminer is working on a block for 60 seconds, and thinks that those shares are valid for 120 seconds, when in reality the new alt-coin network is finding a new block every 10 seconds, a lot of what you do is going to be invalid.

My reject rate on MC has been unacceptable high.  And i am running all 7950s / 270s @ -g 1.

Trying out the -E 10 -s 5 -Q 0 settings.  I'll post the results after a 24 hour sample period.


Title: Re: High reject rate for middlecoin?
Post by: crazyates on February 14, 2014, 01:01:27 AM
Quote
Remember that these 120/60/1 defaults are for Bitcoin, which has a 10 minute block period, and the difficulty recalculates every ~12-14 days. Many alt-coins will have MUCH shorter block times, and recalculate the diff VERY quickly. If cgminer is working on a block for 60 seconds, and thinks that those shares are valid for 120 seconds, when in reality the new alt-coin network is finding a new block every 10 seconds, a lot of what you do is going to be invalid.
I had no idea to even consider this!

My reject rate on MC has been unacceptable high.  And i am running all 7950s / 270s @ -g 1.

Trying out the -E 10 -s 5 -Q 0 settings.  I'll post the results after a 24 hour sample period.
Yep we edit those settings on all of our rigs. I think it results in higher network traffic, but it's pretty insignificant to begin with, so it's not an issue.

Let me know how that works out for you! For every 1% increase in rejects, it's basically a 1% drop in hashrate.


Title: Re: High reject rate for middlecoin?
Post by: hostmaster on February 14, 2014, 03:18:35 PM
i have same problem nearly ,%20 rejects rate now.


Title: Re: High reject rate for middlecoin?
Post by: cryptomining on February 14, 2014, 06:01:51 PM
i lowered my intensity one,  helped with high rejects


Title: Re: High reject rate for middlecoin?
Post by: xbudahx on February 14, 2014, 07:45:05 PM
Quote
Remember that these 120/60/1 defaults are for Bitcoin, which has a 10 minute block period, and the difficulty recalculates every ~12-14 days. Many alt-coins will have MUCH shorter block times, and recalculate the diff VERY quickly. If cgminer is working on a block for 60 seconds, and thinks that those shares are valid for 120 seconds, when in reality the new alt-coin network is finding a new block every 10 seconds, a lot of what you do is going to be invalid.

I had no idea to even consider this!

My reject rate on MC has been unacceptable high.  And i am running all 7950s / 270s @ -g 1.

Trying out the -E 10 -s 5 -Q 0 settings.  I'll post the results after a 24 hour sample period.

I tried these setting with my Gigabyte R9 270s and my reject rate today is under 1%, the best I've done previously was around 2.5%.


Title: Re: High reject rate for middlecoin?
Post by: crazyates on February 15, 2014, 02:05:15 AM
Trying out the -E 10 -s 5 -Q 0 settings.  I'll post the results after a 24 hour sample period.
I tried these setting with my Gigabyte R9 270s and my reject rate today is under 1%, the best I've done previously was around 2.5%.
Glad I could help  ;D


Title: Re: High reject rate for middlecoin?
Post by: hostmaster on February 15, 2014, 05:31:17 AM
Trying out the -E 10 -s 5 -Q 0 settings.  I'll post the results after a 24 hour sample period.
I tried these setting with my Gigabyte R9 270s and my reject rate today is under 1%, the best I've done previously was around 2.5%.
Glad I could help  ;D
Mine looks better now %6-7 thx


Title: Re: High reject rate for middlecoin?
Post by: crazyates on February 15, 2014, 06:32:03 AM
Mine looks better now %6-7 thx
Try what cryptomining said and dropping your Intensity? I notice I get a lot more rejects at I:20 than I do at I:19, and even fewer at I:18. A 2% drop in hashrate is worth it if I drop from 5% to 2% rejects. That's still a 1% net gain.