No game loading speed improvement from RAM disk?

[Chewzie]

Hello.

I've recently tried to put my KSP installation on a RAM drive, but, strangely, I didn't see any major improvements: ~9,5min loading time from (theoretically) ~30GB/s RAM disk vs ~11,7 when loading from 3GB/s SSD.

Have I done something wrong in regards to whole RAM disk setup?

Are loading times like these typical for ~100 mods KSP?

[linuxgurugamer]

I wouldn't call a 2.2 minute decrease "no difference".  That's more than a 15% decrease.

Ssd's are much faster than hard disks.  A large part of that time is involved reading, interpreting and initialized all the mods from that data.

Exactly how many mods do you have, and what are your system specs?

Edited December 18, 2019 by linuxgurugamer

[Chewzie]

14 minutes ago, linuxgurugamer said:

I wouldn't call a 2.2 minute decrease "no difference".  That's more than a 15% decrease.

Ssd's are much faster than hard disks.  A large part of that time is involved reading, interpreting and initialized all the mods from that data.

Exactly how many mods do you have, and what are your system specs?

I didn't say "no difference", but for a 10x difference in read speed, only a 15% decrease is not a major one.

Yeah, I know, my game is currently installed on SSD, not an HDD.

Well, looks like I have over 100 mods actually, now it's 138. My specs are: I7-4980HQ, 16gb ram, GTX1070, adata sx8200 ssd. I've played many heavily modded games before (factorio and skyrim, for example) and never had encountered such long loading times.

[Geonovast]

I think the problem is your relatively low amount of RAM.

If you're allocating a significant portion to a RAM disk, then you're taking a pretty big chunk out of your available RAM, which is going to increase your paging.  So while it might seem that you're doing everything exclusively with RAM, you may actually be paging a lot to your SSD.

Interesting, though.  I may have to play with RAM disk loading times.  My system has 64 GB of physical RAM with swap disabled, so I should be able to get some pretty cut and dry numbers.

[linuxgurugamer]

Also, how long does it take to copy the game to the ram disk?  Probably 1-2 minutes, which will probably be equivalent to the time saved at startup

[Geonovast]

Copying time is probably negligible if you have many KSP starts per system boot.  It could also be set up to do at boot so by the time you actually get around to playing KSP, it's already there. 

I think the biggest risk to keeping KSP in a RAM disk is either forgetting to copy your save files over to real storage before rebooting, or losing save progress to a power or system interruption. That right there I think is worth waiting a few minutes more to have it load.

[linuxgurugamer]

I'm currently in the process of setting up a 2 gig ramdisk to temporarily store save files. Even on SSDs it can be a noticable pause when auto saving a large game.  I'll be writing a batch file to copy it over to the SSD.  Its awkward because I don't  think I can change where the games are stored on KSP, but I haven't looked into that yet

[pmborg]

Hello @linuxgurugamer

• "Ssd's are much faster than hard disks. " and M.2 SSDs  much faster than a SSD
• I use a dedicated M.2 Gen4 NVMe PCI-e 4.0 of 1GB for KSP only as drive K: the burst speed is very high compared to SSD.

Cheers.

 

[linuxgurugamer]

2 hours ago, pmborg said:

Hello @linuxgurugamer

• "Ssd's are much faster than hard disks. " and M.2 SSDs  much faster than a SSD
• I use a dedicated M.2 Gen4 NVMe PCI-e 4.0 of 1GB for KSP only as drive K: the burst speed is very high compared to SSD.

Cheers.

 

1 gig is useless for my games; the installed size can be over 10 gig.

I don't  know why you tagged me on this.  Maybe you meant someone else?

Edited December 18, 2019 by linuxgurugamer

[pmborg]

22 minutes ago, linuxgurugamer said:

1 gig is useless for my games; the installed size can be over 10 gig.

I don't  know why you tagged me on this.  Maybe you meant someone else?

Hello again, I like to talk with experienced people

• yes, I was referring to your sentence 4h ago, but yes ofc my error, I mean 1TB
• I have 7 installations and use 100GB indeed.
• Yes I also have several disks with huge sizes for other games and simulators, but was referring only for KSP, at least for me is nice to clone one entire directory of KSP in a few seconds.

 

[Chewzie]

10 hours ago, linuxgurugamer said:

Also, how long does it take to copy the game to the ram disk?  Probably 1-2 minutes, which will probably be equivalent to the time saved at startup

The copying itself is almost instanteous, but has a long "wind-up" period when system goes through tons of small files (.cfg's, textures and whatnot).

9 hours ago, Geonovast said:

I think the biggest risk to keeping KSP in a RAM disk is either forgetting to copy your save files over to real storage before rebooting, or losing save progress to a power or system interruption. That right there I think is worth waiting a few minutes more to have it load.

You can keep your saves on the physical HDD/SSD and that was actually what I did: I only moved GameData folder on the RAM disk by making a symbolic link to it from the game directory (and maybe that's why I didn't see any major improvement?) because my RAM size is insufficient to move an entire game there while leaving some ram to run it, the OS and other persistent software...

Maybe the game writes somewhere else (cache?) during load and this is the main factor in loading time? So, instead of moving GameData to RAM I need to place that cache folder there?

 

But, anyway, what are your loading time, guys? And how much mods do you have? I've mainly wanted to compare against others to see if this is typical or not...

Edited December 19, 2019 by Chewzie

[Flibble]

Most of the load time isn't disk access it's creating a bazillion parts from your part mods. FWIW I have 80 mods and the game loads in 3 minutes. But I don't have that many part mods.

[Curveball Anders]

As somewhat noted above you have to consider the 3 limiting issues.

• Disk access/read times.
• Processing power to unpack content.
• Memory to memory read/write speed.

The last one should normally not be an issue, but comparing single channel vs double channel install is notable.

And the faster disk read you have, the more impact the raw processing power will have.

There is also one rather obscure thing.

Unity has some issues probing for all possible disks, regardless if they are used, or even present.
There has been reports of very long load times when there's been an unused network adapter or even VPN.

[Arco123]

59 minutes ago, Flibble said:

Most of the load time isn't disk access it's creating a bazillion parts from your part mods. FWIW I have 80 mods and the game loads in 3 minutes. But I don't have that many part mods.

What mods do u run?

[Chewzie]

I've re-did my tests today with only the stock game+dlc, placing an entire game folder on a RAM disk. 

All settings default, game starts in a 1280x720 window:

From program launch to main menu.

SSD (1 start):
70s
SSD (2 start):
68s
SSD (3 start):
68s

RAM drive (1 start):
77s
RAM drive (2 start):
69s
RAM drive (3 start):
68s

Looks like that either my SSD isn't the bottleneck or my ram disk gets swapped to this same SSD.

Can someone with bigger RAM size test this?

[Geonovast]

~70 seconds isn't a bad load time for a stock game.  I don't think you're going to see any improvements from a RAM disk as I don't think the storage medium is what's holding you back.  If you compared the RAM disk results to a spinning mechanical drive, you'd probably see a difference.

I'm not sure I'll see much difference either.  I load the stock game in about 20 seconds off of a mechanical drive.

[Chewzie]

4 minutes ago, Geonovast said:

I load the stock game in about 20 seconds off of a mechanical drive.

What cpu and memory are you using?

[Geonovast]

It's an i7-7700K OCed to 4.8 and DDR4 running at 3333mhz.  Drive is a WD 7200RPM...blue, I think.  I did a comparison once to loading off of my Samsung EVO 970 NVMe drive and didn't see much difference, but I didn't actually time it.  Testing with my laptop would probably get more of a difference.

 

[Chewzie]

14 minutes ago, Geonovast said:

It's an i7-7700K OCed to 4.8 and DDR4 running at 3333mhz.  Drive is a WD 7200RPM...blue, I think.  I did a comparison once to loading off of my Samsung EVO 970 NVMe drive and didn't see much difference, but I didn't actually time it.  Testing with my laptop would probably get more of a difference.

 

Well, looks like its my cpu and memory, probably? I'm 3 gens past you CPU-wise and still on DDR3.

Haven't upgraded back then because intel was too costly and first gen ryzen performed poorly in Factorio, and today it's still about 1200$ to get a decent non-mainstream gaming (by "non-mainstream" I mean games like KSP, Factorio, DF, ONI and other CPU-hungry games that can't utilise many cores, pretty much limiting one to intel CPUs) cpu+mobo+memory combo...