Parity Check Speed Constant around 50MB/s

[xaudzai]

Hello Experts, I having this weird problem and can't figure out why, I have several disk with difference size. my parity check speed is hovering around 50MB/s throughout the whole time. it should be faster in the end after it done with the reading of the smaller disk. I have 1 dell Perc h310 currently on IT P19 paring with intel expander RES2SV240, same thing happen when I use first dell perc h310 dual link to expander and second dell perc H310 8 port with both on P20.00.07.00. Please help.

TIA

atlas-diagnostics-20170815-0901.zip

[JorgeB]

Your parity is assigned to the parity2 slot, parity2 requires considerable more CPU power, you're using an older Opteron and it looks to me like you're CPU limited, if you assign it as parity performance should be noticeably better (note that if you do that you'll need to re-sync parity as it won't be valid anymore)

[xaudzai]

I wonder if dual parity will cause the same issue? Thanks

I am too excited and forgot to Thanks, you are a live saver.

Thanks Sir

Edited August 15, 2017 by xaudzai
Big Thanks

[Frank1940]

2 hours ago, xaudzai said:

I wonder if dual parity will cause the same issue? Thanks

Absolutely,  Parity one is a simple calculation that can be done with a very simple single logical operator.  Parity 2 is a complex matrix calculation that recent processor families have now included a special operator to speed up the process considerably.  Slower CPU's will have significant longer parity check times (as well as any other operaation hat requires a parity calculation) without that operator.  You can read here about this:

 

[xaudzai]

I add parity drive(dual parity) and it currently doing Parity-sync/Data-rebuild, look like Average CPU load less than 15%, I will wait and see when it closing on to the end.

Thanks

[Lev]

Two things

 

1- As started by others, simply try single vs dual parity, that's easy comparison to help know. Your Q calc in your logs is low, like 1923, for the 20 our so drives give got, id say your getting what should be expected.

 

2- preclear and its statistics sister plug-in are clearly having issues, uninstall and wait till you need them again.

[xaudzai]

Thanks for all the help, I am getting 60MB/s in the beginning and 80MB/s closing in in the end (single Parity assigned). I will upgrade the CPUs from 1.8Ghz to 2.6Ghz next week to test again and post the result.

 

[xaudzai]

I am getting average speed around 80MB/sec now, 1 day and 3+ hrs . Thanks all for all the help.

(SOLVED)