# Performance Investigation of vsearch and q2-vsearch **URL:** https://forum.qiime2.org/t/performance-investigation-of-vsearch-and-q2-vsearch/14013 **Category:** User Support **Created:** [March 6, 2020, 1:28pm UTC](https://forum.qiime2.org/t/performance-investigation-of-vsearch-and-q2-vsearch/14013 "2020-03-06T13:28:51Z") **Posts on this page:** 1 **Showing post:** 16
### Author: ![thermokarst](https://forum.qiime2.org/letter_avatar_proxy/v4/letter/t/8e7dd6/32.png) [@thermokarst](https://forum.qiime2.org/u/thermokarst) #### Post date: [April 28, 2020, 2:18pm UTC](https://forum.qiime2.org/t/performance-investigation-of-vsearch-and-q2-vsearch/14013/16 "2020-04-28T14:18:12Z")
Hi @MichelaRiba! Okay, time for that update that I promised. I started working on a simple analysis using the dataset provided here ([link](https://curr-protoc-bioinformatics.qiime2.org/)). First, I did a de novo clustering - it was quickly done. Then I moved on to closed-reference clustering - I observed the same issue you found - vsearch is complete rather quickly (maybe 10-20 minutes), but then _something_ is hung up and going crazy slow. I began a detailed debugging, and identified a huge performance bug in the q2-vsearch code. I owe you an apology - thank you for sticking with it! Basically, the bug only presents itself in certain cases - namely when you have many many many unique features, before clustering. I have submitted a patch ([link](https://github.com/qiime2/q2-vsearch/pull/67)), and the current plan is for this to be included in the upcoming QIIME 2 2020.5 release ([link](https://forum.qiime2.org/t/preview-qiime-2-2020-5-development-changelog/13906)). I think at this point there is no need for your attempt to reproduce. Thank you again for your perseverance, this was a hard one to diagnose and reproduce! Thanks! :qiime2: --- _[View the full topic](https://forum.qiime2.org/t/performance-investigation-of-vsearch-and-q2-vsearch/14013)._