Well that's not me saying it but NickN who seems to be the go to guy on this stuff. Yes O&O will be better because you will be organizing the files in order by name so that there is faster movement of the reading head between files. This is also the reason that you want everything on the same partition (or on different drives altogether) so that the HD head is not jumping all over the place. Mark.

I've been using pc's for near 30 years and not ever have i noticed any speed difference from defraging.....It's a way over the top misconception, in my opinion. It may have had some merits years ago when hard drives were slower, but as the speeds have increased the necessity for defraging becomes increasingly pointless. If people derive comfort from thinking there pc's are in top nick in part because the drive is defragged then it's about the only valid point to me. Just my opinion......

I solved that issue by keeping the processes in the backgroung at a minimum, now I have no stutters at all and I'm running fsx at medium-high settings. Give it a try, I mange the processes with "magic utilities" and noticed that if I keep them under 50 +/- I'm ok. Hope you solve it!

Well that's not me saying it but NickN who seems to be the go to guy on this stuff. Yes O&O will be better because you will be organizing the files in order by name so that there is faster movement of the reading head between files. This is also the reason that you want everything on the same partition (or on different drives altogether) so that the HD head is not jumping all over the place. Mark.

Ah, okay. Luckily, I've got two physical drives, with Win on one and FSX on the other. So that's fine then, yes?

Antilag is the cause to your issues. RenderFrameAhead=0 will fix the stutter. Fragmented disk will not cause stutters and rarely will an AV program unless it's actively scanning the system.

i just did a flight putting the renderahead to 0 and the stutter problem got better, but didn't disappear. the stutters were less frequent and not as long

I guess I stand corrected. I think the render frame = 0 is a better idea

the render frame = 0 on antilag certainly did help. No more stutters at high altitude. I do get stutters on detailed airports (default scenery) and during approach. Also stutters flying through or near REX clouds. Reducing the autogen scenery did help omproving this a bit, but I keep having stutters. Also, disabling the 'create weather station' function in ASE weather seemed to have helped.