Part limit and performance

[Yorou]

Hi, started playing the game about two months ago. I am totally hooked and must have played over 400 hours so far.

In my last play through, I made a huge ship in orbit that totalled over 600 parts. I have pretty good PC but this was too much and the FPS took a huge hit. Looking online, I found that I should limit the number of parts since the game is not designed to handle this much.

My question is, how many parts should I limit myself too? I want to know a rough estimate so I can plan station and bases accordingly and make sure the FPS stays good even with other ships/modules attached.

While on the subject, do docking port assembly make a difference? Meaning, will a station built in one piece have less impact than one built in orbit piece by piece using docking ports.

[Red Iron Crown]

Welcome aboard, Yorou!

First, this is a highly subjective question to which there is no one right answer. Computer specs vary, as does people's tolerance of lower framerates. My best advice would be to play with a few different part count vessels (outside the atmosphere) to get an idea of what your personal limit is.

As for your second question: There is no difference between a ship assembled in orbit and the same ship launched in a single launch. However, the single launch method lets you eliminate the docking ports (saves a few parts) and use struts to make things more rigid (less frustration).

[regex]

200 parts is, IMO, a good limit for a single craft, but that largely depends on the computer you're playing on.

Most of my Realism Overhaul ships come in at under or around 100 parts. This is due in large part to procedurals, which mean I can have a 30m x 50m main tank (if needed) without part spam. In fact, I can spend more parts on better looking rockets and craft because my lifters aren't sucking up the part count. My stock KSP craft generally pack 50~100% more parts and tax my computer more.

[StrandedonEarth]

One way to know if your part count is gettin high is to watch the mission clock in the top left corner. When it's green you're good. When it goes yellow you're getting a little too high. If it's red you're in for a slideshow.

Bear in mind this will vary due to many things, such as what is in the background (water can be bad) on your screen and how much stuff you have in orbit eveywhere. Another thing that can slow it down is if your CPU throttles down to prevent overheating. Somtimes I'd be playing and think "this ship isn't that big; the clock should still be green." So then I'd blow out the vents on my laptop with canned air and it would be full speed ahead

[xtoro]

X2 on procedural tanks. Saves part count drastically. Not sure what changed dramatically in 1.x to make it so much more CPU intensive but probably the new aero calculations. I used to be able to fly 600 part ships smoothly but now my computer struggles with 200 parts... And it's a beast.

[Hagen von Tronje]

Really depends on the craft. A lifter + payload can be rather high part count and I'll tolerate it since it's a 5 minute launch, but I'd rather a spaceplane be as low as possible.

[Slam_Jones]

Wow, you got up to 600 parts? Impressive. I can barely pass 150+ without getting mad at the game turning into a slideshow

It's really about how smooth you like the game to run. I suppose I could do more parts, but it bothers me to have such low FPS. So it's all about your preference.

-snip- I used to be able to fly 600 part ships smoothly but now my computer struggles with 200 parts... And it's a beast. -snip-

Oddly enough, I get a higher framerate in atmosphere (before re-entry effects) than I do in orbit. :|

[Edax]

Some tricks on keeping the part count down is using more efficient parts, bigger/fewer solar panels, sticking the base strut and fuel line on the booster/stage instead of the base spacecraft. Bigger/fewer fuel tanks, batteries ect.

[Ten Key]

Another thing to think about when building space stations in Kerbin orbit is the performance hit you take from the game rendering Kerbin's oceans. The water render distance is 160 km-- above this altitude, the game doesn't render the water and your frame rate will be better. If you're planning a big station, you might want to put it above 160 km.

Welcome to the forums Yorou.

[xtoro]

Wow, you got up to 600 parts? Impressive. I can barely pass 150+ without getting mad at the game turning into a slideshow

It's really about how smooth you like the game to run. I suppose I could do more parts, but it bothers me to have such low FPS. So it's all about your preference.

Oddly enough, I get a higher framerate in atmosphere (before re-entry effects) than I do in orbit. :|

Yeah, my ship Avalon is 657 parts and played at probably 80% speed and about 25 fps.

[problemecium]

Psh. 25 fps is dandy. I don't consider the game unplayable until it drops below 7.

[BlueCanary]

For me, much above 230 parts isn't fun, in either editor or flight. I've never tried pushing it to the point of crashing because it just starts to become frustrating and no fun whatsoever long before then. Sometimes I don't even notice how annoying it is until I start flying a low part ship instead and it's a sudden wave of performance-induced euphoria. This is a lower-midrange computer when it was bought in 2008, and seeing as most other people seem to have a 200-ish limit too I get the idea computer power doesn't really matter unless it's a really fancy one, seeing as my ol' reliable can handle KSP about as well as the (I assume) much more modern machines others are running.

[Alphasus]

I once had 2 ships, one about 700 parts and the other about 600. 1300 parts at about 15-20 fps is playable.

[Slam_Jones]

Yeah, my ship Avalon is 657 parts and played at probably 80% speed and about 25 fps.

Pardon my french, but %#$@!*$ you still get 25 fps at 657 parts??? Sir, I would gladly sell off vital parts of my anatomy to have performance like that.

I once had 2 ships, one about 700 parts and the other about 600. 1300 parts at about 15-20 fps is playable.

My PC would have turned to slag well before I got anywhere near that o.o congrats sir.

I kinda feel like KSP is one of those games that I'll never truly be able to run at full speed (without building an entirely separate, and expensive, PC for it).

Edited August 19, 2015 by Slam_Jones

[keeper]

Haha I remember my first space station where i docked it all together, think it had something like 500 parts, got about 5fps...

That was back in version 0.18 or something and with a bunch of mods for space stations.

I just built the same kind of thing, not so crazy on the mods any more i've limited myself but its got everything i need at 140 parts total. Including about 15 docking ports. 10 - 15fps. Yessss.

[Alshain]

The TweakScale mod will save part counts drastically on structural parts, like Girders and adapters.

[xtoro]

Keep in mind that those were pre-1.x numbers... I dont get that anymore

[Plume & Akakak]

Well I learnt that a 1860 parts vessel will make my game run at 1 fps, with 37 real-world seconds for 1 in-game second.

I miss my nerves.

[Mad Rocket Scientist]

200-250 Parts, and this is on a computer which can run trainz simulator 2010 with high graphics, with almost no lag. In other words, how much lag can YOU handle?

[FleshJeb]

I have heard, but can't find the source, that certain parts contribute to lag more than others. Docking ports in particular.

[Alshain]

I have heard, but can't find the source, that certain parts contribute to lag more than others. Docking ports in particular.

Possible, but I doubt it's significant. The lag comes from the physics calculations at the joints between parts (the only place where physical forces really apply to a rigid body). Because of this, the fewer the parts, the fewer the joints, and the fewer the joints, the less physics calculations your CPU has to do, and that means less lag.

*So if you stack 3 girders end to end, that's 2 joints.

*If you use TweakScale to scale one up to the same size, that is no joints.

*If you use Ubiozur Part Welding, it takes the 3 parts and makes them one in the eyes of the physics engine and therefore has no joints.

[X-SR71]

I find that decreasing part count is one of the fun challenges in the game. I aim at 100 parts and never go above 200.

[Red Iron Crown]

I have heard, but can't find the source, that certain parts contribute to lag more than others. Docking ports in particular.

I have found that struts and fuel lines adversely affect performance more than their part count would suggest, I think the loops they make in the part tree complicate the physics calculations.

[Nefrums]

Interesting. I have read somewhere that parts with the "PhysicsSignificance" flag do not affect performance at all. Seams logical as the are not treated like a separate part in some sense and appear to have their mass/drag added to the parent part.

[Gargamel]

one way to know if your part count is gettin high is to watch the mission clock in the top left corner. When it's green you're good.....

It comes in green!?!?