Dedicated server for coop and performances

[super-truite]

Hello,

I want to get a dedicated windows server, mainly for coop mission (technically dogfight missions but with players only on one side to allow for respawn).
Even with high end CPUs, I hit quite quickly the limits because of AI and the dreaded "Multiplayer Server Overload" kicks in.
I know how to cache AI, but in some situations like when using bomber formations it is difficult to get a satisfying result on my current server.
My guess is that a server with a high CPU clock, say 5 GHz,  would give a nice performance boost for this kind of missions.
Is that so ? Anything else that should be watched out beside clock rate ? Did anyone make AI capacity benchmark with different hardware?

Dedicated server providers are often focused on parallelism and not on high clock rate for single thread games. Any good providers for this niche ?

current server: AMD Ryzen Threadripper 1900X 8-Core Processor    3.80 GHz, RAM: 64 Go, Windows 10 family. 
with 20 bombers in 3 groups I get the "Multiplayer Server Overload".

 

Edit: Some information (apparently the typical hosting provider won't have the right CPUs for the job ? ) :

 

Edited July 14, 2020 by super-truite

[Alonzo]

11 hours ago, super-truite said:

I want to get a dedicated windows server, mainly for coop mission (technically dogfight missions but with players only on one side to allow for respawn).
Even with high end CPUs, I hit quite quickly the limits because of AI and the dreaded "Multiplayer Server Overload" kicks in.
I know how to cache AI, but in some situations like when using bomber formations it is difficult to get a satisfying result on my current server.
My guess is that a server with a high CPU clock, say 5 GHz,  would give a nice performance boost for this kind of missions.
Is that so ? Anything else that should be watched out beside clock rate ? Did anyone make AI capacity benchmark with different hardware?

Dedicated server providers are often focused on parallelism and not on high clock rate for single thread games. Any good providers for this niche

 

IL2 server has one 'hot' thread that limits the overall performance, so anything you can do to improve single-thread performance will help. The server actually responds to hardware quite similarly to the VR game client, prior to the deferred rendering patch. Before that, all the VR-heads were working out how to get the most performance out of their rig. The recipe is usually:

• Intel CPU with good potential for overclocking (9700K is best price/performance here)
• Good CPU cooling (AIO water cooler)
• Good motherboard for overclocking
• Fast, low-latency RAM (3200-CAS-14 is good, or 3600-CAS-16).

Unfortunately, "overclocks nicely" also means "produces lots of heat" so most server hosting companies won't provide this kind of thing. Our provider for Combat Box gives us a 9600K but it's on a 'server' motherboard and limited in the total amount of current the chip can draw. We get about 4.5ghz out of the chip, but if you look at the spec it should turbo up much closer to 5ghz. Sadly the motherboard prevents that.

 

Our provider is reliablesite.net, they have given us good service and good prices. I am somewhat questioning their network, though -- if I ping from Canada to their datacentre it's a longer ping time and more hops than to another server that I run in New York. I'm not sure why.

 

Even with a lot of hardware, though, IL2 fundamentally doesn't like too much Ai, or too many players all in one place in the sky. It makes sense, since this is a high fidelity flight sim. The bombers are running full flight models, not some War Thunder "bombers on rails" flight model. That makes them quite heavy on server performance. Even if you get 20 bombers flying, you should not put them all in one place on the map and then have a bunch of players there too. On our map "Mitchell's Men" we started with 12x B-25 bombers per wave but needed to reduce to 9 per wave for stability and performance.

 

Of course, much of this depends on how many players you want to support. We shoot for 84 players on Combat Box, and that puts a lot of stress on the server. If you're doing co-op and have a smaller number of players, you might be able to do lots of fun stuff with quite a lot of bombers. But do space them out -- 20 bombers in one location is not the same as four groups of 5 spread out across the map. Be especially careful about how much stuff you put into any 10km radius space -- dserver must always inform all game clients of planes within 10km, so you can go from "stable" to "crashed" very quickly if you put things in the same spot.

[super-truite]

Thanks for the detailed answer. I see a few providers giving access to overclocked CPUs at 5GHz but with really cheap memory ?
Since I am aiming for 10ish players, I guess I would have a bit more freedom than you, but it is not really clear to me how performances will scale (I bet highly non linearly) with more GHz.

Any additional advice regarding this specific bomber flight use case you seem to have played with? For instance if I want to get the maximum of bombers in this 10km grid, is the way the formation is structured important ? I will for instance  try several groups vs one group with loose formation (same total amount of bombers), play with skills and priority as well. But if you tested it all I am not against some pointers ? 

[Alonzo]

21 hours ago, super-truite said:

Any additional advice regarding this specific bomber flight use case you seem to have played with? For instance if I want to get the maximum of bombers in this 10km grid, is the way the formation is structured important ? I will for instance  try several groups vs one group with loose formation (same total amount of bombers), play with skills and priority as well. But if you tested it all I am not against some pointers ? 

 

I haven't really tested it. We got 12, it was too slow, so we switched to 9. But the type of bombers makes a difference -- more gunner positions = more load, more engines = more load, etc.

 

A lot of successful mission building is about how to be an illusionist. There's an experience you want to give players, but constraints on how many bombers you can have and in what play space. So get creative. How else can you offer or approximate or give the illusion of the mission experience?

[super-truite]

true, but I find it difficult to achieve something impressive with bombers as we all dream of huge formations "like in the movies" ?.
But after some tests, it turns out that for my use case (small number of players / lots of b25) I can go up to 25-30 bombers in close formation which is already madness (+ flak and fighters) ! 
I used a VM on the PC of a friend which is a beast (I use 2  CPUs at 5.2 GHz and with RAM at 3666Mhz). I get 50 sps and around 10-15 time delay when alone on the server. But I guess I will be able to achieve something playable even at 3-5 players by tuning things a bit.

On a side note it is only recently that I started  il2 editing and I am thus trying to find the limits of what is possible. I am used with the illusionist compromise in other games, 
but I need to hit the walls of the engine on this one to accept it ?.

[Alonzo]

Make sure you test what happens when all those bombers try to shoot things. I've had situations where everything looks fine, then a bandit dives into the B-25s and they open up like the Death Star. And then the server crashes ?

[=RS=Stix_09]

On 7/14/2020 at 10:14 PM, super-truite said:

with 20 bombers in 3 groups I get the "Multiplayer Server Overload".

 

As soon as I read that I though,  well that ain't happening....
No one can run 20 heavy bombers in il-2 GB , and get it to perform.

 

Multicrew planes are probably the worst thing for performance, more crew and it gets worse. As Alonzo said, the AI have to fly the plane same as any player. There is no special AI flight model in IL-2.

 

You may find planes like the B25 , better than the player controllable planes, no internals are modeled... not tested this yet.

Edited July 22, 2020 by =RS=Stix_09

[super-truite]

Are you calling me a liar ?. ?No really, joke aside it worked, but only with an overclocked machine ( 5.2 GHz,  RAM at 3666Mhz). For 3 players in Me262, and a few AI fighters on the german side the limit before getting less than 50 sps and more than 20ms time delay was 24 b25 bombers separated in 6 4-bomber formations (skill = ace and waypoint priority = medium to allow gunner action). It gets really unstable when someone connects though but for a short coop mission this is not a problem I just have to make people join before starting. An other problem is that flight records do not work well unfortunatly (planes are a bit shaky in flight record but not in game). 
The mission file is attached  (nothing fancy this is just a benchmark Dogfight mission).


 

b25_test.zip

Edit: Btw, could it be working because I use the B25 and not playable planes ? The simulation might be simplified ?

[=BKS=T0R0]

Quote

I apreciate a lot your post about requirements for Dserver, but I have some doubts because this post date is 2020, for a high load server is better a normal cpu like i9 or server cpu like a Xeon? and other question is, this server run with windows server?

 

Thanks Alonzo.

On 7/14/2020 at 11:36 PM, Alonzo said:

 

IL2 server has one 'hot' thread that limits the overall performance, so anything you can do to improve single-thread performance will help. The server actually responds to hardware quite similarly to the VR game client, prior to the deferred rendering patch. Before that, all the VR-heads were working out how to get the most performance out of their rig. The recipe is usually:

• Intel CPU with good potential for overclocking (9700K is best price/performance here)
• Good CPU cooling (AIO water cooler)
• Good motherboard for overclocking
• Fast, low-latency RAM (3200-CAS-14 is good, or 3600-CAS-16).

Unfortunately, "overclocks nicely" also means "produces lots of heat" so most server hosting companies won't provide this kind of thing. Our provider for Combat Box gives us a 9600K but it's on a 'server' motherboard and limited in the total amount of current the chip can draw. We get about 4.5ghz out of the chip, but if you look at the spec it should turbo up much closer to 5ghz. Sadly the motherboard prevents that.

 

Our provider is reliablesite.net, they have given us good service and good prices. I am somewhat questioning their network, though -- if I ping from Canada to their datacentre it's a longer ping time and more hops than to another server that I run in New York. I'm not sure why.

 

Even with a lot of hardware, though, IL2 fundamentally doesn't like too much Ai, or too many players all in one place in the sky. It makes sense, since this is a high fidelity flight sim. The bombers are running full flight models, not some War Thunder "bombers on rails" flight model. That makes them quite heavy on server performance. Even if you get 20 bombers flying, you should not put them all in one place on the map and then have a bunch of players there too. On our map "Mitchell's Men" we started with 12x B-25 bombers per wave but needed to reduce to 9 per wave for stability and performance.

 

Of course, much of this depends on how many players you want to support. We shoot for 84 players on Combat Box, and that puts a lot of stress on the server. If you're doing co-op and have a smaller number of players, you might be able to do lots of fun stuff with quite a lot of bombers. But do space them out -- 20 bombers in one location is not the same as four groups of 5 spread out across the map. Be especially careful about how much stuff you put into any 10km radius space -- dserver must always inform all game clients of planes within 10km, so you can go from "stable" to "crashed" very quickly if you put things in the same spot.