Problem with reconstruction of CTF corrected tomograms in Warp using nvidia P3200

[Jan Felix]

Hi all,

I am currently processing a set of tilt series using Warp. I am using a mobile DELL workstation with Windows 10 OS, 32 GB RAM, an Nvidia quadro P3200 GPU (6 GB memory of GDDR5 type , pascal achitecture) and the folder with frames stored on an external HD. I installed the newest nvidia driver for my GPU (version 441.66) and have .NET framework vesion 4.8 installed as well.

Tilt movie pre-processing, importing tilt series from IMOD and 3D CTF correction all work smoothly. However, reconstruction of the full-tomograms (15 A/pix) seems to finish without errors but gives very strange results (all black tomos, or with black and grey parts and strange patches with artefacts).

First I assumed there was a problem with the alignment files generated in Etomo, but a colleague of mine could succesfully reconstruct tomograms in Warp using my files from two different tilt series (and corresponding taSolution and .xf files from Etomo) as an input without any problems at all. He is using an almost identical mobile workstation, but with the sole difference that he has a slightly newer Nvidia quadro RTX3000 GPU (6 GB memory of GDDR6 type,Turing architecture).

I was wondering if anybody experienced similar problematic behaviour during reconstructing tomograms using a similar GPU as mine? Is there a possible fix for this?
Best regards,
Jan Felix

[Jan Felix]

Hi,
My gpu was not the issue. It took a while to find out, but in the end I traced the problem to my regional windows 10 settings for decimal separator symbol (comma vs dot). While initial ctf estimation and 3d ctf correction seem to go fine, having a comma as the decimal separator in regional settings apparently interferes with tomogram reconstruction. Changing regional settings to English (uk), with a dot as decimal separator instead of comma, completely fixed the issue. Maybe this could be addressed in a future Warp update?
Best regards,
Jan