Unconfigured Ad

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • lcdog
    Junior Member
    • Jun 2017
    • 2

    #1

    Blastx speed issue...?

    Hey all! First time poster here.
    I am blasting 122,000 transcripts against the NCBI NR database (using NCBI-blast 2.6.0). Have downloaded the database and formatted it and am using the following command

    /blastx -query ***.fasta -db nr -outfmt "6 qseqid sseqid salltitles pident length slen mismatch gapopen qstart qend sstart send evalue bitscore" -num_alignments 1 -max_hsps 1 -num_threads 18 -out ***.txt

    now the issue i'm having is that each set of 16 transcripts are taking about 10min to blast before the next 16 begin, meaning at the rate i'm going i'll be blasting for 60 days before I have this complete. Is there anything I can do to speed this process up? Or have I done something incorrectly? Or is this just the normal speed and process? (I'm running on a cluster with 20 cores and 120gb RAM)

    Thanks
  • GenoMax
    Senior Member
    • Feb 2008
    • 7142

    #2
    NR is a large databases and this may be the normal speed for your particular cluster.

    People sometimes prefer using DIAMOND or PLAST as a speedier alternative to BLAST. You would need to make your own nr reference indexes for these packages.

    Comment

    • jonfoox
      Junior Member
      • May 2017
      • 3

      #3
      Keep in mind that only certain phases of the BLAST algorithm can be hyperthreaded. So even though you are requesting -num_threads 18, the majority of the search is being done using just one. There's evidence that you get diminishing returns with the more threads you request – see http://voorloopnul.com/blog/how-to-c...g-num_threads/

      Using another algorithm like GenoMax suggested is likely a good idea, but if you are stuck with BLASTX, the more you can parallelize the better. Do you have access to a cluster, where you can BLASTX many sets of 16 transcripts at once?

      Comment

      Latest Articles

      Collapse

      • SEQadmin2
        Beyond CRISPR/Cas9: Understand, Choose, and Use the Right Genome Editing Tool
        by SEQadmin2



        CRISPR/Cas9 sparked the gene editing revolution for both research and therapeutics.1 But this system still showed severe issues that limited its applications. The most prominent were the heavy reliance on PAM sequences, delivery limitations, double-stranded breaks that prompt unintended edits and cell death, and editing inefficiency (both in targeting and in knock-in reliability).

        Despite this, “CRISPR helped turn genome editing from a specialized technique into
        ...
        07-31-2026, 11:01 AM
      • SEQadmin2
        Proteomic Platforms: How to Choose the Right Analytical Strategy to Improve Detection and Clinical Applications
        by SEQadmin2


        Proteomics platforms are evolving rapidly, with advances in mass spectrometry and affinity-based approaches expanding what researchers can detect and at what scale. As the field moves toward deeper proteome coverage and clinical applications, scientists face an increasingly complex landscape of tools. This article will explore how researchers are navigating these choices to find the right platform for their work.

        The systematic characterization of the human proteome has
        ...
        07-20-2026, 11:48 AM

      ad_right_rmr

      Collapse

      News

      Collapse

      Topics Statistics Last Post
      Started by SEQadmin2, Yesterday, 10:05 AM
      0 responses
      8 views
      0 reactions
      Last Post SEQadmin2  
      Started by SEQadmin2, 08-13-2026, 12:22 PM
      0 responses
      33 views
      0 reactions
      Last Post SEQadmin2  
      Started by SEQadmin2, 08-11-2026, 10:35 AM
      0 responses
      27 views
      0 reactions
      Last Post SEQadmin2  
      Started by SEQadmin2, 08-06-2026, 07:41 AM
      0 responses
      38 views
      0 reactions
      Last Post SEQadmin2  
      Working...