KSP and Crossfire (or SLI)

[fireblade274]

SO I just ordered another HD6950 to compliment my existing one, not [I]specifically[/I] to get KSP better fps, but really to get me through another year or 2 till i can throw down big bucks for a 980ti (yes im confident ill make a switch back to Nvidia)

After a week the card arrived today without a crossfire bridge even though they guy said it was coming with [I]all[/I] original accessories :(, so I overnight-ed a bridge and it should be here in 24 hours.

My question is does KSP like dual GPU configurations? I believe Claw told me It doesn't like overclocked GPU's and that could be a reason why the game crashes for me every 2-3 hours when changing buildings/scenes (though I still get them occasionally even when I clock it back to standard)

Ever since the 1.05 update, my frame rates have dropped dramatically even for craft with a low part count (less then 100 parts) and I have
-a i5 4690k watercooled and OC to 4.25
-an HD 6950 2gb video ram
- 8gb of ram
-only 3 mods installed; KIS/KAS, kerbal alarm clock. Waiting for Atmosphere trajectories and Engineer to be updated
-win 7 pro

I have always run the game on 100% settings and I do not want to compromise that. In previous versions i was not getting bad fps unless my craft had more then 300-400 parts, and even then it only became unplayable after about 600 parts. Since the update, im getting 12 fps on average and 4 fps at the worst. Its really annoying when I believe I have a great CPU and decent GPU.

Will this second GPU help me out with this issue? Is my set up really suddenly inadequate now??

[sal_vager]

Wow, tough question, I wouldn't know to be honest, but more graphics power [I]can[/I] help if the gpu was bottle necking your system, for example I upgraded from the AMD Radeon built into my cpu to a separate Nvidia card and there was a big improvement.

As to whether KSP will like SLI will depend on Unity, it should work, though I hear that SLI is dying off as newer cards don't benefit from it.

And yeah overclocking will crash KSP, it really can't take much overclocking at all.

[Elthy]

I doubt a second 6950 will help your performance much, even with an overclocked i5 you will hit the CPU limit quite fast. Are you playing in 4k?
Anyway, going for Crossfire/SLI is almost allway a bad thing, you are almost allway better of with a single, stronger card. Now you have 2 very outdated cards with 2 Gb VRAM, which also eat way more energy than a new one.

How does Overclocking crash KSP other than due to unstable high clockrates? I have my CPU overclocked since forever, i never had issues...

[fireblade274]

[quote name='sal_vager']more graphics power [I]can[/I] help if the gpu was bottle necking your system, for example I upgraded from the AMD Radeon built into my cpu to a separate Nvidia card and there was a big improvement.[/QUOTE]

Hm, it would be interesting (and scary) if my single gpu is bottlenecking my system; in my limited understanding I thought you only encountered bottlenecking when you had 2+ GPU's put together with an outdated and underpowered CPU. I like to think the i5 4690 is a very good cpu and would not encounter bottlenecking with a single card, i spent 200$ on it less then a year ago when it went on sale

[quote name='Elthy']I doubt a second 6950 will help your performance much, even with an overclocked i5 you will hit the CPU limit quite fast. Are you playing in 4k?
Anyway, going for Crossfire/SLI is almost allway a bad thing, you are almost allway better of with a single, stronger card. Now you have 2 very outdated cards with 2 Gb VRAM, which also eat way more energy than a new one.

How does Overclocking crash KSP other than due to unstable high clockrates? I have my CPU overclocked since forever, i never had issues...[/QUOTE]

I am running all my games at 1080p as I do not (yet) have a 4k monitor. I know that a single card is usually better then 2, but I did not have enough money to buy a single card that would do better then what I hope to gain with 2. My 6950 may be outdated, but I do not believe its life is over yet. I can run Shogun 2 on ultimate settings, and max army sizes with the one 6950 and my top of the line i5. Also, Im not the least bit concerned with power consumption. I have 750w psu and Ive been told by multiple others online that that should be enough to power 2 6950's, plus my utility's at college are all inclusive heh

Also, unless I don't understand correctly, what Sal and Claw are saying about KSP crashing and overclocking only applies to the GPU..?

[Elthy]

Ksp is one of the most CPU demanding games ever, while having quite bad graphics. No wonder the CPU would be a bottleneck, its a completly different case than most modern games that use good graphics, but have to limit their CPU since they also have to run on those realy bad console CPUs.

[fireblade274]

I still dont understand how my CPU would be bottlenecking; KSP is coming to the xbox one, and my CPU is at least decently better then the Xbox One CPU

[Elthy]

That will hopefully change with Unity 5, in the moment i doubt the Xbox would somehow be able to run it.

[Red Iron Crown]

[quote name='Elthy']How does Overclocking crash KSP other than due to unstable high clockrates? I have my CPU overclocked since forever, i never had issues...[/QUOTE]
This has been my experience, too. If the overclock is stable under load then KSP will run fine on it, and better than at stock clocks.

Edit for below: Ah, OEM overclocking software, I can see how that could be a problem. I OC the old-school way, in the BIOS (though not in the really old school way, which involved manipulating the motherboard physically :)). Edited November 17, 2015 by Red Iron Crown

[sal_vager]

Mine was bottle necking because it's a cruddy Radeon 8-something built into the APU, so has awful cooling, no RAM of its own and is really not much use for anything more demanding than Plants V Zombies.

And yes KSP can crash if you overclock, the latest culprit being the PrecisionX graphics card monitoring and overclocking software, if you're overclocking and not crashing then great! If you start crashing try reducing or disabling the overclock...

[Joshwoo70]

[quote name='Elthy']Ksp is one of the most CPU demanding games ever, while having quite bad graphics. No wonder the CPU would be a bottleneck, its a completly different case than most modern games that use good graphics, but have to limit their CPU since they also have to run on those realy bad console CPUs.[/QUOTE]

I dont find it true... (comparing with AAA games) Anno 2205 uses some of my cpu.

looking from your specs... I think gettig a Nvidia graphics card would be a good choice.. even those from the GTX 600 series are good. Edited November 17, 2015 by Joshwoo69

[Elthy]

Why would you recommend a similar outdated Nvidia card?

[fireblade274]

Alroight, so after crossfireing 2x hd6950's, my fps has increased on average 3 fps, bringing my average now to about 10 from 7 fps; this took place while launching/ascending with a 225 part spaceplane. The fps increase is barely noticeable, but welcome.
Again, I am running on full settings at 1080p

Do I really need to upgrade my CPU to like an i7 4790k to get like at least 20 fps?? Is this game THAT CPU demanding that a i5 4690k OC just wont cut it at max settings now? Its not even at 4k resolution!

Even if I did, hyperthreading wont even be supported till 1.1 at Christmas, and other then hyperthreading my OC i5 is not that different at all from an i7 4790. Can some one tell me this will get better with optimization lol. Again, the game is coming to Xbox 1 and my i5 is decently better then the Xbox 1's CPU

[Elthy]

The i7 wont increase your FPS, maybe you are just using to many parts.

[fireblade274]

If 225 parts is too much, that's too bad. I've used 400 parts before the 1.05 update and i still didnt get lag this bad till 500+. I run 3 non demanding mods, kerbal alarm clock, and KIS/KAS. The craft doesnt even have KIS/KAS parts on it. Could it because I downgraded to Win 7 pro from Win 8.1? Also I just read somewhere that KSP only uses one CPU core. Is that true?

[Elthy]

For now it only uses 1 core, that will change with 1.1

[fireblade274]

DAS GOOD! With my limited knowledge of software, I'd be willing to bet the issue im having with low fps is due to the game only using 1 core, or 25% of my CPU when this is a CPU intensive game, especially after the updates 1.05 brings. And though im not surprised it doesn't support hyperthreading yet, I am surprised it still only uses one core Edited November 18, 2015 by fireblade274

[Red Iron Crown]

Another thing you can check is if your CPU is throttling itself. Some CPU management software does not correctly interpret a single high-load thread on a multicore processor, all it sees is "CPU is at 25%, no need to have it at full speed" and turns down the clockspeed.

[fireblade274]

[quote name='Red Iron Crown']all it sees is "CPU is at 25%, no need to have it at full speed" and turns down the clockspeed.[/QUOTE]

BRILLIANT. That never crossed my mind. I'm going to see if I can turn off that throttle in the BIOS and get it to run constantly on my OC. Thank you!

[Camacha]

[quote name='fireblade274']Is this game THAT CPU demanding that a i5 4690k OC just wont cut it at max settings now?[/quote]
No. There seems to be an issue with your configuration.

[quote]Its not even at 4k resolution![/quote]
High resolutions generally do not load you cpu.


[quote]Even if I did, hyperthreading wont even be supported till 1.1 at Christmas, and other then hyperthreading my OC i5 is not that different at all from an i7 4790.[/quote]
This i5 will never hyperthread. Multithread, yes. Two rather different things.

[fireblade274]

[quote name='Camacha']This i5 will never hyperthread. Multithread, yes. Two rather different things.[/QUOTE]

You misunderstand, I already know this. I was referring that the the only difference is that the i7 4790 has hyperthreading and my i5 4690 does not have hyperthreading, but that is basically the only difference between the 2 as mine is OC'd.

[Camacha]

[quote name='fireblade274']You misunderstand, I already know this. I was referring that the the only difference is that the i7 4790 has hyperthreading and my i5 4690 does not have hyperthreading, but that is basically the only difference between the 2 as mine is OC'd.[/QUOTE]

You speak of hyperthreading being supported. Hyperthreading is never supported, multithreading might be. You seem to be confusing the two.

[jrodriguez]

Hi all,

I have asked this in the Technical Support area, but maybe you give me some advice. I'm using the latest crimson beta drivers but my second card is never used with KSP. My crossfire is working properly for other games (with the crossfire logo showing up) but KSP no crossfire and no logo...

 

[StrandedonEarth]

9 hours ago, jrodriguez said:

Hi all,

I have asked this in the Technical Support area, but maybe you give me some advice. I'm using the latest crimson beta drivers but my second card is never used with KSP. My crossfire is working properly for other games (with the crossfire logo showing up) but KSP no crossfire and no logo...

 

KSP really doesn't need crossfire/SLI. KSP, even 1.1, is limited by the CPU, not graphics.

[jrodriguez]

13 minutes ago, StrandedonEarth said:

KSP really doesn't need crossfire/SLI. KSP, even 1.1, is limited by the CPU, not graphics.

haha thanks I already know that. But if you have small part count then, the bottleneck is not the CPU . A soon as you go > 200 parts you can see how your GPU usage goes down because the CPU is doing bottleneck.