Suttering on older system

[Amgarrak]

ATA SAMSUNG HD642JJ SCSI Disk Device

[akortunov]

ATA SAMSUNG HD642JJ SCSI Disk Device

That's an ancient device. More likely it causes your stuttering (see my post about sounds loading).
I'd suggest to check the drive for SMART errors (e.g. via HDDScan) and run a defragmentation at least.
Or better to migrate to any SATA SSD.

Also you can try to install previous OpenMW releases (0.47, 0.46) to check if they have the same issue.

[AnyOldName3]

I think they'd already said 0.48 was worse than 0.47, so there's a chance it's down to us changing a default setting (in which case, they can change it) or us doing more processing than before (in which case, there's not much we can do).

[akortunov]

I think they'd already said 0.48 was worse than 0.47, so there's a chance it's down to us changing a default setting (in which case, they can change it) or us doing more processing than before (in which case, there's not much we can do).

I saw only a post where TS had issues with RC7, but RC8 fixed that issue.
I did not find an actual releases comparison (except of vague "it worked fine on some kind of unknown release 32-bit build a long time ago").