I was investigating the Horizon VFR London demo yesterday and although fps were very slow (6-10), I also noticed that when panning around in VC or Spot view, the screen would suddenly fill with vertical spikes - I think eminating from various autogen.Has anyone else noticed this phenomenon / graphic glitch and can suggest what might be causing it? Is it a driver issue or simply memory? I had installed latest released NVidia drivers 176.15.I had also scaled down max_autogen to Trees 200, Buildings 100 taking into acount recent post by Phil Taylor.My pc is rather old:AMD Athlon 2.4 mhz, 2 GByte DDR RAM, 7600GT AGP graphics+256 ram.Any advice welcome?Regards,Stuart

When old meets new.Alot of us even, even though we are drilled from birth to use the latest drivers, revert back to ones that are stable and worked.So the first thing I would try is going back to what worked.Those in particular, caused STUTTERS on my system.Vertical spikes can be caused by many things but I get them, if I OC the cards or computer to much or in some cases, any at all, heat build up,or a graphics setting that I changed.But with 256 of card ram, I am surprised you can even fly over a large city.Defragged, well maintained and with a new card, your system shold run FSX ok at reduced settings.Good Luck

Many thanks for the advice. Unfortunately I cannot justify the expense at present of upgrading my PC, other family issues dictate. Guess I shall try earlier graphic drivers and turn down autogen/scenery. Problem only seems to be acute over large cities like London around which I get my lowest fps.Thanks again,Stuart

I agree with JimJam. You're running low on memory and will have to lower your settings until you upgrade your system. Recommend at least a Dual Core CPU.Best regards,Jim