Sign in to follow this  
Gypsy Baron

File access behavior for add on photoscenery

Recommended Posts

We've talked about this before, some users experiencing long load times when using add-on photoscenery such as Horizon Simulation Generation X. In my experience this is 15 minutes, on an E6400 with 2x SATA300 250GB in RAID0 stripe configuration. Other users report it to be as little as a few minutes.Using filemon, I analysed the problem in a slightly different way than before. I filtered on just one scenery file v3-12-11754207.BGL, a few hundred miles away from the chosen starting position. If you want to see the full trace, you can look here:http://forum.horizonsimulation.com/viewtop...?t=534&start=50In summary, v3-12-11754207.BGL is opened, read and closed many times, and seemingly the same part: Offset 0 length 188, and offset 0 length 4096. This is somewhere in the 5-35% "loading" progress bar.For what I saw in the filemon tracemon, it seems that FSX is responsible for this problem, as only it can decide what files to access. Specifically, my questions are1) Why so many reads? The file is opened, read a couple of times then closed. This cycle is repeated many times during the early FSX load process.2) Why so many reads at 0 for 188 bytes, and 0 for 4096 bytes? What is so important in the first 4K page of a BGL file?Can anyone whom understands the BGL file structure interpret this? And if this is the behavior for one file, I can see why the load time grows exponentially for many files.Any comments?Simon

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

In looking at another problem the other day, my texture memory suddenly going from 50% used to 100% used ( it usually stays at30-50% ), I fired up filemon and noticed some strange addon scenery access. I was flying an IFR flight plan from Halifax, N.S. to Sydney, N.S. and FSX was reading from a BGL in my Tallinn, Estonia addon folder! Sometime back I read in one of the forums that someone from Aces admitted that the way FSX was intended to work, vis-a-vis scenery textures, was NOT the way it was actually working. In a word, it's PORKED! I've noted alot of other irregularities in FSX's behavior using file monitor. Unfortunately there are so MANY of them it's difficult to get a handle on them... Paul

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this