Jump to content

Preload Radius: Definition Please


ErichVon

Recommended Posts

  • 5 years later...

Correct answer according to YO-YO on ED Team

 

This is an edited version of an answer that was marked as correct by YO-YO who is on the ED team.

Preload Radius is: "How far out terrain information is preloaded from disk and cached in RAM.

 

Lower values should result in smaller, more frequent loads.

Higher values result in larger, less frequent loads.

The optimum value for your system will depend mostly on disk read performance and RAM speed/quantity.

I'm unsure as to whether or not preloading is conducted in a background thread."

Link to comment
Share on other sites

  • 11 months later...

btw: how would preload radius and SSD vs HDD relate? What i am getting at; if i have DCS running from a SSD instead of a 7200rpm HDD, would i not get away with a smaller preload radius since streaming from the SSD should be more rapid and hopefully fast enough to prevent DCS from stuttering? Less preload radius might in my layman understanding lead to less memory use and faster level/mission loading times?

Link to comment
Share on other sites

btw: how would preload radius and SSD vs HDD relate? What i am getting at; if i have DCS running from a SSD instead of a 7200rpm HDD, would i not get away with a smaller preload radius since streaming from the SSD should be more rapid and hopefully fast enough to prevent DCS from stuttering? Less preload radius might in my layman understanding lead to less memory use and faster level/mission loading times?

 

I'm having similar thoughts.

 

It seems everyone just flicks the preload slider to max thinking it will prevent stutter but maybe reducing it will actually work better if the HD can load the smaller chunks more frequently and remain invisible to the player.

Link to comment
Share on other sites

So i have searched for all threads with preload radius in the title, its only about 8 or so. But its still not really well explained how the preload mechanic works and how your drive might influence it. But, we are in the P-51 forum section, not the most prominent place to discuss this.

Link to comment
Share on other sites

I have been running preload at around 30% and was only using around 12GB of ram. Upped the preload to 50% and my ram usage jumped to 20gb, which is fine as I have 24GB. In short, looks very useful for tuning to a system.

System: 9700, 64GB DDR4, 2070S, NVME2, Rift S, Jetseat, Thrustmaster F18 grip, VPC T50 stick base and throttle, CH Throttle, MFG crosswinds, custom button box, Logitech G502 and Marble mouse.

Server: i5 2500@3.9Ghz, 1080, 24GB DDR3, SSD.

Link to comment
Share on other sites

Im using a fairly small preload radius for both VR (25) and monitor (50). Like Mr_sukebe says, it impacts memory, but also, I prefer more frequent tiny load stutter, to a less frequent bigger stutter, like a freeze. With a small preload radius and running of a SSD, the load stutters are tiny and barely noticeable for me.

- Jack of many DCS modules, master of none.

- Personal wishlist: F-15A, F-4S Phantom II, JAS 39A Gripen, SAAB 35 Draken, F-104 Starfighter, Panavia Tornado IDS.

 

| Windows 11 | i5-12400 | 64Gb DDR4 | RTX 3080 | 2x M.2 | 27" 1440p | Rift CV1 | Thrustmaster Warthog HOTAS | MFG Crosswind pedals |

Link to comment
Share on other sites

+1

9./JG27

 

"If you can't hit anything, it's because you suck. If you get shot down, it's because you suck. You and me, we know we suck, and that makes it ok." - Worst person in all of DCS

 

"In the end, which will never come, we will all be satisifed... we must fight them on forum, we will fight them on reddit..." - Dunravin

Link to comment
Share on other sites

It would be very useful to have an estimated ram usage value displayed next to the preload radius slider.

 

I'm not sure that could be implemented - even in an empty mission the RAM usage may differ greatly from one location on the map to another.

 

The slider in the options screen, as it currently stands, has no idea what terrain you're planning to use, nor does it know where on the map you are planning to spawn - you might spawn in the mountains or you might spawn over a huge city.

 

The real-time CTRL-Pause info might be a good place to monitor RAM usage but I've never had much luck deciphering it.

Link to comment
Share on other sites

Just had me thinking, you can edit the preload value directly in options.lua

 

["preloadRadius"] = 150000,

 

I wonder if you could push this much higher and stop the problems with the terrain surface being drawn when switching views on maps such as the Persian Gulf.

Link to comment
Share on other sites

Im using a fairly small preload radius for both VR (25) and monitor (50). Like Mr_sukebe says, it impacts memory, but also, I prefer more frequent tiny load stutter, to a less frequent bigger stutter, like a freeze. With a small preload radius and running of a SSD, the load stutters are tiny and barely noticeable for me.

 

Are you sure this is how it works? What i mean is; the size of the preload radius (and i have no idea how this works in DCS) must not necessarily translate into less or more loading operations. It could equally well load the same tiny amount of 10mbps except that the outer edge is pushed out way further with max preload radius.

 

Hrm, i just did a bad, quick and dirty test repeatedly loading some instant action missions with mix or max preload radius and i did not see any difference in loading speeds nor private bytes/working set DCS memory usage. I don't know, maybe this starts making a difference when actually flying a over terrain for a greater distance. I guess one would have to fly the same long mission twice with rebooting in between to really find out.

 

It's metric values so 150000 = 150km.

 

The DCS World manual states on page 19; ''PRELOAD RADIUS. Radius of the preloaded terrain around user position in meters. A large setting can decrease hard disk swapping but it requires more system RAM. ''

 

But, the min. value is 100...if it really is a metric value, 100m preload radius makes no real sense to me.

 

Kinda don't understand why ED staff never took the time to make a detailed explanation about this setting so we woulnd not need to play the testing and guessing game.

Link to comment
Share on other sites

Are you sure this is how it works?

 

Nope, but thats the experience I have. It could simply just be a radius added to the 80km LOD range (is already a radius) there seems to be on the furthers away objects (when checking graphics.lua). So when ever something that isnt in memory yet reaches your pre-load, it gets loaded in. If your memory, be it system memory, gpu memory or even pagefile, reaches its limit, then we get the big stutter (load freeze) for x amount of ms or seconds. If plenty of free memory, then the load hit just becomes this tiny stutter, all depending on the data size, memory speed, drive speed etc.

 

Is of course all pure speculation. But after many different pre-load values, I settled for the 25 and 50, as being the less intrusive for me.

 

DCS seems to just fill the memory, it doesnt want to dump anything, until a given memory is full. You can jump between different modules in the same mission, and it just keeps eating memory. Can also confirm that by jumping back into a module, it will load instantly. So leaving an object behind outside your X radius, doesnt mean it gets throw own out of memory. Might be queued as the first to go, when memory is full?

- Jack of many DCS modules, master of none.

- Personal wishlist: F-15A, F-4S Phantom II, JAS 39A Gripen, SAAB 35 Draken, F-104 Starfighter, Panavia Tornado IDS.

 

| Windows 11 | i5-12400 | 64Gb DDR4 | RTX 3080 | 2x M.2 | 27" 1440p | Rift CV1 | Thrustmaster Warthog HOTAS | MFG Crosswind pedals |

Link to comment
Share on other sites

''So leaving an object behind outside your X radius, doesnt mean it gets throw own out of memory. Might be queued as the first to go, when memory is full?''

 

Probably, but i feel this is the standard way Windows memory management works. Keeping all already loaded stuff in memory even if not used anymore and only designating it to be overwritten if free memory space decreases. What i have seen yesterday was that DCS's memory working set was almost always double the size than DCS's memory private bytes. I wonder what DCS is loading into memory but not actively using. And that happend even when i have loaded one map only. And loading a mission on another map takes quite a bit longer than reloading the same map, what makes me think DCS does not keep all maps in mememory.

Link to comment
Share on other sites

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...