different assemble runing megahit with same sample and same parameters

[feihongloveworld]

i run many times for a sample with megahit，but got different assmble fasta ....... What does make the difference ？ cmd as below：

megahit -r R1.fastq -o xxxx --out-prefix xxxx or megahit -1 R1.fastq -2 R2.fastq -o xxxx --out-prefix xxxx

[fconstancias]

megahit -r R1.fastq -o xxxx --out-prefix xxxx : you are using only R1 megahit -1 R1.fastq -2 R2.fastq -o xxxx --out-prefix xxxx : you are using both R1 and R2 of your pair-end librairy