voutcn / megahit

Ultra-fast and memory-efficient (meta-)genome assembler
http://www.ncbi.nlm.nih.gov/pubmed/25609793
GNU General Public License v3.0
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Very different results running megahit v1.2.9 with same parameters on two different clusters #263

Closed SonWende closed 4 years ago

SonWende commented 4 years ago

Hello,

while attempting to assemble a metagenomic sample with megahit with the option meta-large, I noticed that i get two very different results for running megahit with the same parameters on two different clusters. The only difference in the running parameters come from the fact, that different number of cpus and memory are available on cluster 1 and 2: megahit used 256 threads and 0.9 of 504 Gb memory on one system, and 80 threads and 0.9 of 95 GB memory on the other system.

This results in

(For more stats see the attached Quast report. I will also attach the megahit options.json)

I already saw that megahit is not deterministic, bit this seems to be to vast a difference. I also checked, that it is the same version of megahit; both installations are megahit 1.2.9

Do you have any idea what may have caused this? And i how can i proceed, so that i can have a trustworthy assembly?

Thank you very much in advance

Cluster2-options.txt HPC-options.txt report.txt

voutcn commented 4 years ago

It seems that you used L_R1.fasta.gz for both forward and reversed reads.