What part of the PC related to the framerate drop of huge amount of parts ?

[ThePULSAR]

Is it GPU or CPU or the harddrive?

[eddiew]

CPU I believe. It's mostly physics processing that causes issues with many parts.

Of note, there isn't a lot of point in springing for the most expensive i7 you can get, because KSP has one-vessel-one-thread physics and it can't make use of the extras. You're best with an overclocked i5  

You could also investigate the welding mod to reduce the number of physics calcs needed ^^

[cantab]

CPU. Basically KSP simulates a spacecraft as a bunch of parts connected together by joints. This means that what each part does depends on what all the other parts do, and that's why the CPU load goes up faster than the number of parts, and also why even in KSP 1.1 the multithreading isn't great.

[JoeNapalm]

 

The answer is always RAM.

 

-Jn-

[Curveball Anders]

27 minutes ago, JoeNapalm said:

 

The answer is always RAM.

 

-Jn-

The answer is never RAM, unless your rig is paging or crashing.

[ThePULSAR]

43 minutes ago, eddiew said:

CPU I believe. It's mostly physics processing that causes issues with many parts.

Of note, there isn't a lot of point in springing for the most expensive i7 you can get, because KSP has one-vessel-one-thread physics and it can't make use of the extras. You're best with an overclocked i5  

You could also investigate the welding mod to reduce the number of physics calcs needed ^^

 

31 minutes ago, cantab said:

CPU. Basically KSP simulates a spacecraft as a bunch of parts connected together by joints. This means that what each part does depends on what all the other parts do, and that's why the CPU load goes up faster than the number of parts, and also why even in KSP 1.1 the multithreading isn't great.

............ interesting.Games nowaday doesn't really rely on CPU that much 

[eddiew]

5 minutes ago, ThePULSAR said:

............ interesting.Games nowaday doesn't really rely on CPU that much 

KSP is not like most games. Most games have rigid body models where physics can be applied to the entire object at once. The objects can be incredibly complex with hundreds/thousands of vertices, but they're generally solid lumps until something interacts with them. The onus is thus on the graphics card until such a time as something causes the object to break up into many objects, if it ever does.

KSP however has a ships made of individual, simple parts, the behaviour of each affects the behaviour of every other part, which means more parts makes for more physics. At best the physics calcs are proportional to the number of parts, at worst to the square of the number of parts. The graphics are relatively simple however, so the GPU tends to speed ahead of the CPU.

It's well documented, but you're welcome to use something like GPU-z to monitor your graphics card usage while playing. CPU will almost always be 100% during flight, but my old nVidia 760 is down on 30-50% usage most of the time. 

If you really want to build big ships, check the options file and change the maximum physics-delta time to its highest setting. The game will run yellow or red clocks more often, which means it isn't keeping up with real-time (e.g. 1 in-game second may take 3 RL seconds to pass) but it might improve your framerate and lead to a smoother experience  

Edited May 20, 2016 by eddiew

[Curveball Anders]

11 minutes ago, eddiew said:

CPU will almost always be 100% during flight

Note that multi-core/HT cpu's are often reported as one cpu, so even if the most active core is maxed out, cpu usage is still reported as 25 or 50%

And splitting the physics calculations of a single ship over multiple cores is not an easy task ...

[eddiew]

15 minutes ago, Curveball Anders said:

Note that multi-core/HT cpu's are often reported as one cpu, so even if the most active core is maxed out, cpu usage is still reported as 25 or 50%

Yeah, sorry, I should have said "one of your CPUs will almost always be 100% during flight."  I tend to think of any single core being maxed as meaning the whole thing is maxed - which is basically true for KSP, Minecraft, WoW and a few other games  

[JoeNapalm]

47 minutes ago, Curveball Anders said:

The answer is never RAM, unless your rig is paging or crashing.

The fastest CPU in the world, waiting for RAM, is still idle. -- Konfucious

 

-Jn-

[monophonic]

20 minutes ago, eddiew said:

Yeah, sorry, I should have said "one of your CPUs will almost always be 100% during flight."  I tend to think of any single core being maxed as meaning the whole thing is maxed - which is basically true for KSP, Minecraft, WoW and a few other games  

It works like that on Linux. 400% CPU utilization FTW!

[eddiew]

15 minutes ago, JoeNapalm said:

The fastest CPU in the world, waiting for RAM, is still idle. -- Konfucious

Except they don't in any practical application   If you don't have enough and you're waiting for SWAP, then yes absolutely more RAM. If you're debating 2000MHz memory vs 3200MHz, it's a performance increase of single digit percentages, if that...

[Enorats]

CPU. Hard drive only affect to loading. SSD's will start the game a bit faster. GPS is graphics. KSP has simplistic graphics, so it's never the limiting factor. RAM deals with memory, and how much data can be "ready to go" at once. Until recently it was capped at 4 gb, something most computers are well over. With 64 bit KSP that cap is gone, meaning we can use more mods which eat up memory. If your game is crashing to desktop, you may need more RAM.

CPU is all about number crunching. KSP needs lots of number crunching. Even the best CPU's out there run slowly when you get above a couple hundred parts.

[JoeNapalm]

31 minutes ago, eddiew said:

Except they don't in any practical application   If you don't have enough and you're waiting for SWAP, then yes absolutely more RAM. If you're debating 2000MHz memory vs 3200MHz, it's a performance increase of single digit percentages, if that...

 

I'll just leave this here:

-Jn-

[cantab]

1 hour ago, JoeNapalm said:

The fastest CPU in the world, waiting for RAM, is still idle. -- Konfucious

 

-Jn-

Simple enough to test with any motherboard that lets you change the memory frequency and timings, which is most decent boards. Slow the memory down and measure the impact on fps. I expect that in KSP it will be modest, and much less in percentage terms than the memory speed drop or absolute latency increase.

[Jarin]

15 minutes ago, JoeNapalm said:

 

I'll just leave this here:

-Jn-

The point is that memory only helps up to a certain point. So it is not "always the answer" as you say above. Sure, if you're running a huge pile of mods, you might eventually get up to the range where 8gb starts feeling tight (I've never gotten to even half that myself, but just for the sake of argument we'll go with it), but once you upgrade to have enough, you won't see any improvement past that. In a world where new computers are coming with 16gb, and a kit with that much only costs $50-$60, memory just isn't that much of an issue anymore.

[steve_v]

8 minutes ago, JoeNapalm said:

I'll just leave this here:

And what, precisely, is a "show us your memory usage" thread supposed to prove?
Yes, KSP uses ridiculous amounts of RAM. So what? VMSize is largely irrelevant if you are running 64bit, and VMRSS is only an issue if it exceeds your physical memory and the OS starts swapping. Swapping will likely tank your framerate (though this depends on what gets swapped out), but Neither VMSize nor VMRSS should have any impact on performance whatsoever - any halfway modern PC has more memory bandwidth than KSP will ever need.

[ThePULSAR]

If KSP only rely on single core,then the i7-6700K probably is the best CPU. Although Xeon E7 or I7-5960X has many threads and cores,caches than any of the others,their single core performance is just poor,can't even complete with a i5 

[cantab]

The 6700K and 4790K earn a nod if you really don't want to overclock. Otherwise, the 6600K or 4690K are just as good for KSP (and virtually as good in most other games) for a lot less money. But really, basically any modern mainstream Intel CPU at a good clock speed will do nicely for KSP.

Relatively poor CPUs for KSP including anything from AMD, Intel's ultra-mobile CPUs which sometimes show themselves in cheaped-out laptops and desktops, and Intel CPUs prior to Sandy Bridge. All of these are lacking the per-core performance that KSP benefits from.

Edited May 20, 2016 by cantab

[Majorjim!]

5 hours ago, eddiew said:

CPU I believe. It's mostly physics processing that causes issues with many parts.

Of note, there isn't a lot of point in springing for the most expensive i7 you can get, because KSP has one-vessel-one-thread physics and it can't make use of the extras. You're best with an overclocked i5  

You could also investigate the welding mod to reduce the number of physics calcs needed ^^

I disagree, an i7 will always be a better buy than an i5. Not only do the i7s have higher clock speeds, un-overclocked, they also have more cache, 3MB to 6MB compared to 4MB to 8MB on the i7s. The i7s have Hyperthreading which may not be used by KSP but who only uses their high end PC for just KSP?

If you can afford it always buy an i7 over an i5. You wont regret it. And if you want to overclock go for a 'K' variant. They have one setting change overclock and can run at nearly 5GHZ on air alone.

 Oh, and KSP now uses multiple cores for multiple craft on screen which is ace for surface bases and complex multi-part craft.

Edited May 20, 2016 by Majorjim

[cantab]

A bit situational for 8 rather than 6 MB of cache to make a significant difference.

You'll regret buying the i7 if it means compromising too much on some other aspect of your build.

[eddiew]

46 minutes ago, Majorjim said:

I disagree, an i7 will always be a better buy than an i5.

I won't argue that an i7 always be slightly better than an i5   Whether it's a better buy depends on your requirements. For KSP, if you really want to max it, you have to be talking overclocking, and both parts tend to reach about the same frequency. What it then comes down to is Hyperthreading + cache, and from what I remember of various benchmarks, it's just not that big an advantage most of the time. And costs 50% more; money which you might well be better adding to your GPU budget.

Totally agree that i7-K is the best bang on the market, but i5-K, imho, is the best bang for buck, for someone looking to upgrade specifically for KSP without busting the bank. Sorry, should probably have made it clearer that I tend to come from a minimum-budget perspective when asked about hardware  

[Majorjim!]

Just now, eddiew said:

I won't argue that an i7 always be slightly better than an i5   Whether it's a better buy depends on your requirements. For KSP, if you really want to max it, you have to be talking overclocking, and both parts tend to reach about the same frequency. What it then comes down to is Hyperthreading + cache, and from what I remember of various benchmarks, it's just not that big an advantage most of the time. And costs 50% more; money which you might well be better adding to your GPU budget.

Totally agree that i7-K is the best bang on the market, but i5-K, imho, is the best bang for buck, for someone looking to upgrade specifically for KSP without busting the bank. Sorry, should probably have made it clearer that I tend to come from a minimum-budget perspective when asked about hardware  

I can't argue with that, well put.

[Enorats]

When I got my new rig a couple years back I didn't know a whole lot about processors. I ended up going with an i7 4820K, and it's worked great. Most of the "comparision" websites I looked at placed it as being equal or better than basically any of the others. Even the newer version of the same, the 5820K, seems to be basically identical in performance. It's got slightly slower cores but 6 instead of 4 though.. not as good for a game that relies so heavily on single core performance.

[Tig]

58 minutes ago, eddiew said:

I won't argue that an i7 always be slightly better than an i5   Whether it's a better buy depends on your requirements. For KSP, if you really want to max it, you have to be talking overclocking, and both parts tend to reach about the same frequency. What it then comes down to is Hyperthreading + cache, and from what I remember of various benchmarks, it's just not that big an advantage most of the time. And costs 50% more; money which you might well be better adding to your GPU budget.

Totally agree that i7-K is the best bang on the market, but i5-K, imho, is the best bang for buck, for someone looking to upgrade specifically for KSP without busting the bank. Sorry, should probably have made it clearer that I tend to come from a minimum-budget perspective when asked about hardware  

This. This.  This.  100 times this. 

The advantage of hyperthreading in the vast majority of games is absolutely de minimus.  If games could actually take full advantage of hyperthreading you know who would be happiest?  Not i7... octocore AMD cpu owners would rejoice to the heavens.  Why do most people suggest i5s and i7s for gaming over AMD?  Simply put they are way faster on a per core per clock basis - but a lot of times that doesn't matter.  Games are not well multithreaded generally speaking.  But then again, most games are not heavily cpu dependent.  Most rigs with most games are going to be gpu limited.  (if you have 2xFury or 2x980ti in your system congrats!  But you ain't "most rigs"  )  Hence why AMD cpus are perfectly fine for most games unless you get a really high end gpu. 

BUT, kerbal is different.  Its probably the most cpu dependent/limited game I've played in the last decade.  1.1 really helped squeeze some extra power out of the cpu, but my OC 6600K still sits around 40% usage.  A 6700K just isn't going to give you any more than that per clock.  Yes, I am aware that 6700Ks typically OC an additional ~100MHz above the 6600K, but 1) that's luck of the bin and 2) that's nothing to do with hyperthreading.