Terrain generation causes very slow chunk loading

More blocks = More time to generate

The amount of blocks is the same in every world. Air blocks are blocks nonetheless. Even so, making a world completely unplayable... those must be some special blocks or something.

What are your system specs?

Same happening to me. No problem on multiplayer, just on SP for me.

My System:
Dell N5010 (the model with the AMD VGA and the I5 processor)
OS: Windows 7 Ultimate 64b.
Java stuff:
java version "1.7.0_60"
Java(TM) SE Runtime Environment (build 1.7.0_60-b19)
Java HotSpot(TM) 64-Bit Server VM (build 24.60-b09, mixed mode)

EDIT:
I've just updated to the last java version (u67) and it keeps happening. In fact the problem looks like what would happen with HIGH ping on a server. When you try to drop items you drop nothing, when you try to spean, nothing pops on the chat window.

EDIT2:
I've just added more screenshots showing what is going on. The world IS generating, but at a REALLY slow pace.

EDIT3:
This is my launcher log after the failed attempt of creating a new world:

[02:23:25] [Thread-6/INFO]: Initializing LWJGL OpenAL
[02:23:25] [Thread-6/INFO]: (The LWJGL binding of OpenAL. For more information, see http://www.lwjgl.org)
[02:23:25] [Thread-6/INFO]: OpenAL initialized.
[02:23:25] [Sound Library Loader/INFO]: Sound engine started
[02:23:28] [Client thread/INFO]: Created: 512x512 textures-atlas
[02:23:35] [Client thread/INFO]: Deleting level New World
[02:23:35] [Client thread/INFO]: Attempt 1...
[02:23:43] [Server thread/INFO]: Starting integrated minecraft server version 14w33c
[02:23:43] [Server thread/INFO]: Generating keypair
[02:23:43] [Server thread/INFO]: Converting map!
[02:23:43] [Server thread/INFO]: Scanning folders...
[02:23:43] [Server thread/INFO]: Total conversion count is 0
[02:23:43] [Server thread/INFO]: Preparing start region for level 0
[02:23:44] [Server thread/INFO]: Preparing spawn area: 5%
[02:23:45] [Server thread/INFO]: Preparing spawn area: 14%
[02:23:46] [Server thread/INFO]: Preparing spawn area: 26%
[02:23:47] [Server thread/INFO]: Preparing spawn area: 38%
[02:23:48] [Server thread/INFO]: Preparing spawn area: 51%
[02:23:49] [Server thread/INFO]: Preparing spawn area: 64%
[02:23:50] [Server thread/INFO]: Preparing spawn area: 75%
[02:23:51] [Server thread/INFO]: Preparing spawn area: 89%
[02:23:52] [Server thread/INFO]: Changing view distance to 24, from 10
[02:23:53] [Server thread/INFO]: clodan[local:E:aec2f15c] logged in with entity id 270 at (-106.5, 62.0, 264.5)
[02:23:53] [Server thread/INFO]: clodan joined the game
[02:24:36] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 44036ms behind, skipping 880 tick(s)
[02:24:36] [Server thread/INFO]: Saving and pausing game...
[02:24:36] [Server thread/INFO]: Saving chunks for level 'New World'/Overworld
[02:26:24] [Server thread/INFO]: Saving chunks for level 'New World'/Nether
[02:26:24] [Server thread/INFO]: Saving chunks for level 'New World'/The End
[02:26:24] [Server thread/INFO]: [clodan: Set own game mode to Survival Mode]
[02:26:24] [Server thread/INFO]: [clodan: Set own game mode to Creative Mode]
[02:26:24] [Server thread/INFO]: clodan has just earned the achievement [Taking Inventory]
[02:26:24] [Server thread/INFO]: [clodan: Set own game mode to Survival Mode]
[02:26:25] [Client thread/INFO]: [CHAT] Your game mode has been updated
[02:26:25] [Client thread/INFO]: [CHAT] Your game mode has been updated
[02:26:25] [Client thread/INFO]: [CHAT] clodan has just earned the achievement [Taking Inventory]
[02:26:25] [Client thread/INFO]: [CHAT] Your game mode has been updated
[02:26:34] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 117294ms behind, skipping 2345 tick(s)
[02:26:36] [Server thread/INFO]: [clodan: Set own game mode to Creative Mode]
[02:26:36] [Client thread/INFO]: [CHAT] Your game mode has been updated
[02:26:42] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 8715ms behind, skipping 174 tick(s)
[02:27:18] [Server thread/INFO]: Changing view distance to 16, from 24
[02:27:18] [Server thread/INFO]: Saving and pausing game...
[02:27:18] [Server thread/INFO]: Saving chunks for level 'New World'/Overworld
[02:29:13] [Server thread/INFO]: Saving chunks for level 'New World'/Nether
[02:29:13] [Server thread/INFO]: Saving chunks for level 'New World'/The End
[02:30:38] [Server thread/INFO]: Saving and pausing game...
[02:30:38] [Server thread/INFO]: Saving chunks for level 'New World'/Overworld
[02:31:32] [Server thread/INFO]: Saving chunks for level 'New World'/Nether
[02:31:32] [Server thread/INFO]: Saving chunks for level 'New World'/The End
[02:33:16] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 6459ms behind, skipping 129 tick(s)
[02:33:36] [Server thread/INFO]: Saving and pausing game...
[02:33:36] [Server thread/INFO]: Saving chunks for level 'New World'/Overworld
[02:34:26] [Server thread/INFO]: Saving chunks for level 'New World'/Nether
[02:34:26] [Server thread/INFO]: Saving chunks for level 'New World'/The End
[02:36:20] [Server thread/WARN]: Biome ID is out of bounds: 182256, defaulting to 0 (Ocean)
[02:36:20] [Server thread/WARN]: Biome ID is out of bounds: 182256, defaulting to 0 (Ocean)
[02:36:20] [Server thread/WARN]: Biome ID is out of bounds: 182256, defaulting to 0 (Ocean)
[02:36:20] [Server thread/WARN]: Biome ID is out of bounds: 182256, defaulting to 0 (Ocean)
[02:36:20] [Server thread/WARN]: Biome ID is out of bounds: 182256, defaulting to 0 (Ocean)
[02:36:20] [Server thread/WARN]: Biome ID is out of bounds: 182256, defaulting to 0 (Ocean)
[02:36:20] [Server thread/WARN]: Biome ID is out of bounds: 182256, defaulting to 0 (Ocean)
[02:36:20] [Server thread/WARN]: Biome ID is out of bounds: 182256, defaulting to 0 (Ocean)
[02:36:32] [Server thread/INFO]: Changing view distance to 32, from 16

screenshots with more information

I get the following when the problem appears:

[18:41:15] [Server thread/INFO]: Preparing start region for level 0
[18:41:16] [Server thread/INFO]: Changing view distance to 32, from 10
[18:41:16] [Server thread/INFO]: Nectaril[local:E:2a7e4345] logged in with entity id 7 at (1759.2420703674322, 182.19270656530824, 3340.572802817696)
[18:41:16] [Server thread/INFO]: Nectaril joined the game
[18:41:23] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 6788ms behind, skipping 135 tick(s)
[18:42:11] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 35162ms behind, skipping 703 tick(s)
[18:42:16] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 4959ms behind, skipping 99 tick(s)
[18:51:42] [Client thread/INFO]: Warning: Clientside chunk ticking took 1478 ms
[19:04:23] [Server thread/INFO]: Nectaril lost connection: TextComponent{text='Disconnected', siblings=[], style=Style{hasParent=false, color=null, bold=null, italic=null, underlined=null, obfuscated=null, clickEvent=null, hoverEvent=null, insertion=null}}
[19:04:23] [Server thread/INFO]: Nectaril left the game
[19:04:23] [Server thread/INFO]: Stopping singleplayer server as player logged out
[19:04:23] [Server thread/INFO]: Saving and pausing game...
[19:04:23] [Server thread/INFO]: Saving chunks for level 'Heroes'/Overworld

This line: [18:51:42] [Client thread/INFO]: Warning: Clientside chunk ticking took 1478 ms
and the ones before it are when the game was falling back so much that I could fly out of render distance even at 32 chunks max render distance. Just flying into the nothingness. At some point it stopped saying that it can't keep up. Even so I could see that it was lagging because it was drawing chunks as if I were at one of my previous positions in the world.

I added a map render that shows what happens to the terrain if you just fly through and leave the game before it finishes actually rendering the terrain (after it's generated). That fly to > generate > render process can take up to 10 minutes.

Edit: In addition to the map I also discovered that the missing chunks don't get properly populated when they are finally generated. So far what I've noticed is that they miss snow coverage. Trees seems to be ok.

this sort of thing never happened in 1.7 or earlier, and when customized world were added, only the more complex ones (ones similar to amplified) would do this understandably. even amplified worlds loaded normally on my computer in 1.7.

now, in more recent snapshots (and the release too), my game does this with all world types, of all shapes and sizes. i also get messages in the log saying the internal server is 40000 (40 thousand) ms behind, and skipping hundreds, if not thousands of ticks. again, wasnt a problem in early 1.8 snapshots or 1.7.

http://pastebin.com/aJT9Bmsg

here is a log of mine from 14w33a. i get very similar logs whenever i generate a new world in 1.8 release. this log is from a map that was already generated and well established. note that at one point the server was over 70000 (70 thousand) ms behind. its not too uncommon that i get reports like this in the log on maps that i have had for months, if not years, not just new maps.

my specs:

windows 7 64 bit
java 1.8.0
nvidia gtx 680
intel i5 3.4 ghz processor

i run minecraft with 8 GB of ram. my usual settings are full smooth lighting, fancy graphics, no vsync, VBOs on, mipmapping level 4, unlimited fps, and 24 chunk render distance. lowering any of these settings does not affect chunk loading. also note that my framerate never drops once. i basically experience lag in the same way one would with a slow internet connection to a minecraft server: slow chunk loading, and blocks taking upwards of 10 seconds to actually break.

also note that none of this happens on multiplayer servers, however. if i run any of my single player maps on a local server client (one that i run on the same computer as the game, connected to via "localhost"), i dont experience any of the aforementioned issues. i have not tried LAN however. this does prove that it is something with the internal server, so im assuming LAN play is affected as well.

overall, it renders single player unplayable.

edit: to prove that it is still an issue, here is a log of a world i just generated in 1.8 release:

http://pastebin.com/Di8hWPGR

where it says "marioman66 joined the game", the game itself was still at the "downloading terrain" screen, and stayed there for a good 10 seconds before showing an empty skybox as the chunks have not loaded yet (and it took the chunks themselves about 15-20 seconds to load). beyond what was eventually initially rendered, the world hardly generated. i could fly out to the edge of the visible world, and had to sit and wait for chunks to load (and they only loaded one at a time). when i finally pressed save and quit, it took about 10 to 15 seconds to actually return to the main menu (it was trying to save the world, which took an abnormally long time). the game even stopped responding for a bit.

WAI. MC-63093

Try setting lower render distances.

Still an issue as of 1.8.1-pre1.
Can provide further technical details, if neccessary

@unknown: What render distance are you using? MC-63093 (closely related) was marked as intended since the people that confirmed it set their render distances too high.

For faster chunk loading, you can put your Max Framerate on '70 fps' (or something around that), and when you have a slow computer you can put it on 30 / 40 / 50 fps. Then your computer does not try to get extreme high framerates, so your computer can do other things, such as loading chunks.

Can reproduce in 1.8.1-pre2 with "Tunneler's Dream" superflat preset on my netbook (Windows 8) using render distance 4 and default resourcepack. Although I didn't experience the "sinking into the void" issue, upon moving the game froze.

I get this in 1.8.1-Pre 1 , 2 and 3. I come here to research it and All i see is people blaming the computer of the user. Really?? Are you kidding me? If was a computer problem it would NOT affect so many users. And please STOP with the automated responses This is NOT "Working as Intended" this is what exactly what i expect from Microsoft. Bugs being dismissed / ignored and never looked in to and fixed. Do not take my word for it. Look at all the "Resolved" Or "Working as Intended" bugs here that are unassigned to a real person.

can confirm

I can confirm this

https://www.youtube.com/watch?v=V4h9KN-fvmY
This video basically explains it all, for some odd reason in minecraft 1.8 if you have your settings maxed out your game will refuse to finish "downloading terrain" the solution is to turn your render distance down into the normal range
Here is what the launcher says while minecraft gets stuck on "downloading terrain"
[17:10:51] [Server thread/INFO]: Scanning folders...
[17:10:51] [Server thread/INFO]: Total conversion count is 0
[17:10:52] [Server thread/INFO]: Preparing start region for level 0
[17:10:53] [Server thread/INFO]: Preparing spawn area: 7%
[17:10:54] [Server thread/INFO]: Preparing spawn area: 16%
[17:10:55] [Server thread/INFO]: Preparing spawn area: 28%
[17:10:56] [Server thread/INFO]: Preparing spawn area: 41%
[17:10:57] [Server thread/INFO]: Preparing spawn area: 56%
[17:10:58] [Server thread/INFO]: Preparing spawn area: 68%
[17:10:59] [Server thread/INFO]: Preparing spawn area: 85%
[17:11:00] [Server thread/INFO]: Changing view distance to 32, from 10
[17:11:00] [Server thread/INFO]: coolgamerovr90[local:E:6818938d] logged in with entity id 205 at (13.5, 62.0, -86.5)
[17:11:00] [Server thread/INFO]: coolgamerovr90 joined the game
------------------------------------------------------------------------------------------
at this point the client screen displays "downloading terrain" and starts playing in game music
------------------------------------------------------------------------------------------
[17:11:44] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 44074ms behind, skipping 881 tick(s)
----------------------------------------------------------------------------------------
at this point you get let into the game and all you see is a world with nothing in it, see the first screenshot
---------------------------------------------------------------------------------------
[17:11:55] [Client thread/INFO]: [CHAT] Saved screenshot as 2015-03-16_17.11.55.png
[17:12:13] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 29607ms behind, skipping 592 tick(s)
[17:12:16] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 2891ms behind, skipping 57 tick(s)
-------------------------------------------------------------------------------------------
At this point you finally get taken into a playable world.
on slower less powerful computers the JVM itself will just crash

And yes 1.8.3 is also an affected version

This issue exists in a way more severe form in 15w14a, not that 15w14a matters, just goes to show that if this isn't fixed it will only get worse as new stuff is added

I have this issue as well. I was using 1.8.7. I went back to 1.8.4 thinking since that is the last version I played, but this is the first time I've played Single Player in a while. My render distance was set to 32 and I didn't have any issues when running MC Vanilla Server. I lowered the render distance to 10 and the issue is mostly solved. The CPU does seem to be running quite high for what it normally runs (50~70% with all chunks loaded).

How I produced the issue:

I created a new world using a custom seed while my render distance was set to 32 chunks. It takes a few minutes to load the world from "Downloading terrain" screen and seems "stuck. Once loaded, I would drop to the bottom of the world. After a minute or so (or much longer) it would load me back up to the surface, but only some of the chunks would be loaded... I would be able to walk off the "cliff" so to speak where the chunk stopped and float to the bottom being able the side(s) of entire chunks floating in air.

My FPS is fine, it's mainly the high CPU load. It is running 90%+ during the beginning when all the chunks are loading and everything is "hung". It is running 50~70% the other times which seems pretty high for what it normally runs. FPS is in the 200-300 range.

When I turn the "render distance" to 10 it seems to be fine. Adjusting this slider though while in a world pretty much Minecraft to the point I have to force it to close out. I'm sure if I waited 5 minutes, it would load, but still...

This is a newly built machine using on-board and a dated NVidia PCIE graphics card. I've had no problems in the past with this setup and the video drivers are up to date. The drivers are up to date on both. I am using three monitors, but MC is only open on the "main" screen. I have been using three screens for a while.

Here are my specs:

Intel Core i5-4670K 3.40 Ghz Quad
Windows 8.1 (64bit)
SSD drive
Gigabyte B85M-D3H
16GB of RAM
2X Video card with three monitors at HD resolution (1080p):
Intel HD Graphics 4600
NVIDIA GeForce GTS 450 PCI-E (fairly old, but it does what I need it to do)

I can confirm this is till a thing for even 1.8.4. Completely unmodified client redownloaded and still even a quick generation of a new world with no customization at all still does exactly what this bug is doing and its acting exactly like what the screenshots show. Just outside of world chunk load range the chunks will fail to load and the TPS drops so far down that one of the logs showed the following which was the worst tick rate before I exited the game.

[19:03:07] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 132438ms behind, skipping 2648 tick(s)

I would like to know if there is at least a workaround for it.

A workaround for this is lowering the render distance.

I have gone to the fastest settings in the game and the chunk loading still is a major problem. The pasted part of the log was when every setting I had was at its lowest / fastest setting that minecraft has. Even optifine for 1.8.4 did not help at all. Loading the world to 1.7.10 and the terrain generation beyond the chunks already loaded would load with 1.7.10 generation.

Wow, what specs does your pc have? CPU, RAM, HDD, GPU

Things like these are for me common as well: [19:03:07] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 132438ms behind, skipping 2648 tick(s)
Both with and without optifine.

BTW, which mapping utility is used to create the last image? And is it Mac-compatible 😉 ?

I am having the exact same problems that have been described. I have been playing Minecraft for a long time, and have always had the odd chunk not load, or the loading time slow down a bit here and there. But nothing quite like this when making new games with the advanced customization type.
Everything from the slow falling, the time lapses, 30 sec+ delay on exiting the game, fps freeze ups every 3 secs at some points and this " [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 132438ms behind, skipping 2648 tick(s)"
My hardware should be fine, the CPU is a bit dated but should do the trick for Minecraft.
AM3 2.8ghz 6-core (running at 3.5)
evga gtx770 2gb
intel 256gb solidstate system drive
16gb 1600mhz ram
rez @ 1080 on Win10
latest drivers and java

I have not found any kind of solutions yet, just wanted to let people know that they are not alone 🙂

Happens to me too.
Tested on render distance 10-11-14
Game version: 15w35b
Java: 1.6.0_65
Allocated RAM: 1GB of 2GB

Affects 15w35b on Default world type.

Is anything being done here? This is still a problem for me in all of the 1.8 versions to date.

Still valid as of 15w51b T_T

Is this still an issue in the most recent versions (currently that is 1.10.2, or 16w42a) of Minecraft? If so, please update the affected versions and help us keeping this ticket updated from time to time. If you are the owner/reporter of this ticket, you can modify the affected version(s) yourself.

Still an issue with the most recent version of minecraft. Generating chunks makes the chunk loading very slow, and it makes the world laggy, by laggy I mean that the TPS (Ticks Per Second) goes down. When I close the game, in the launcher appears a lot of messages of "Can't Keep Up! Running behind X amount of ms" and so..

Confirmed in 1.9 mcpe my render distance is 6 chuncks in a realm a possible solution would be to check of the player is moving too fast and reduce the loaded Chuck from left and right and use it to load chuncks in the direction player is moving or stop server from synchronizing data if it's speed is too high

Not updated for most recent versions. If the bug persist, please reopen the ticket.