Basically it just gives up. The odd thing is during that time in the "biome" section of the debug it randomly flickers between "Forest" and "Taiga" and "Ocean" and "Extreme Hills" as if the engine can't decide what to render.
When chunks load properly, they load really fast, but a lot of the time they seem to not load for a couple of minutes (i've seen similar things on the xbox version in videos, where they're trying to get somewhere but have to stand and wait for the next chunk to load). I went in /gamemode 1 so i could fly past the edge, but the chunks took a long time to load behind me.
I think I'm going to have to call 1.8 unplayable. I'm generally running at 2 fps with 0 chunks loading. Changing my render distance doesn't even help - I still get that poor performance at the 2 chunk render setting. I've spent the last 3 hrs experimenting with all the new settings and nothing helps. Occasionally, I'll get a momentary spike of 20+fps, but it only lasts less than a second. I got killed by a spider because I froze in place while the spider was able to attack me unaffected by the freezing. xD In the snapshots, I was able to do stuff as long as I was underground, but that's not even helping today. Also, terrible block lag, I tend to have to break blocks 2-3 times before they're actually broken.
I have experienced a major drop in fps. With default settings I get on average 1-15 fps with giant lag spikes that make the game unplayable in single player. I managed to get my fps up to on average 30-40 fps by altering my settings.
For those who are having problems here's a list of what helped for me:
Launched Visibility - Close launched when game starts (this helped majorly!)
Increased my memory up to 2GB (JVM Arguments: -Xmx2048M -Xms2048M)
Reduced Render Distance to 10 Chunks
Set Particles to Minimal
Turned Clouds Off
Turned VSync Off
Turned Use VBOs Off
Turned 3D Anaglyph Off
Set Max Framerate to Unlimited
Turned Allow Snooper Off
This problem has gotten progressively worse for the last couple of updates and 1.8 became unplayable for me on default settings until I made these changes.
This is 14w29b - when threaded chunk loading was introduced:
Look at the GPU usage percent - this is how it is supposed to be.
Aside from the weird spike in FPS look at how smooth the graph is! The world plays very smooth - like a hot knife going through butter!
Compare again to the 1.8 release:
GPU usage is very low.
Of course Mojang knows all the kids will like to brag "I GHOT 183405 FPS IN TEH MYNEKHRAT NOW!11!!!!!" so it almost seems they rigged something to make it seem the frame rate is high.
I told all of you - FPS DOESN'T MATTER - what matters is the CONSISTENCY of FPS because that affects your perception of how "smooth" the game plays for you.
As an aside look at this screenshot of 14w29b:
Almost 300 chunks updating and it still runs smooth.
This was the best snapshot of all.
What the hell happened between then and now? It has to be the crappy lighting engine update.
You're only showing the GPU performance, while Minecraft relies a lot on the CPU as well. Could you show us CPU charts as well?
Even though I am not affected by these problems, I want to know more about them, and find out what exactly causes them. Then we might be able to provide Mojang with enough information to fix it, or to mod a fix into the game ourselves if that doesn't happen.
From those charts showing that GPU usage is lower in 1.8, I think that was Mojang's intention. Demanding less of the GPU means better performance on GPUs with poor performance. Also, if you look at those frame rates, they're consistently higher, with the occasional spike. In the 1,7 graph, the measurements were all over the place, high, low, spiking ridiculously. Mojang's main goal with this update was to increase performance and efficiency, which they indeed accomplished according to those graphs.
Making the game more efficient means it performs better on low performance equipment and demands less of required systems. This is what Mojang wanted to do, and I think they have.
Also, CPU performance does indeed matter, especially to those with lower performance CPUs and integrated graphics. Minecraft is very GPU and CPU intensive, and when the processing has to be carried out by the same device things can get very slow very quickly. With my AMD dual-core 2.4 GHz processor I consistently hit 100% while playing Minecraft. Actually, it's at 100% most of the time when playing the game.
I'm not trying to defend Mojang and start a big fight. I'm just saying that they accomplished much of what they said they'd do. The FPS drops on some machines probably has to do with hardware and software conflicts that weren't present before, since they basically rewrote the entire game. They will be worked out in time. However, I do agree that the chunk loading issue does absolutely need to be fixed and they should have definitely fixed it before releasing the update. It seems to be a universal issue, no matter the equipment.
I also noticed in places where there are large underground ravines the frame rates and lag become really horrible in the immediate area - it's almost like a cheat to know there is a large hole a few blocks underneath the ground. The absolutely worst thing to do is stand there and turn and look in all directions.
I haven't noticed any issues related to this; in particular, I just modded* the cave generator class to produce several times as many caves as usual (the same number present before 1.7 reduced them) and other than taking a few more seconds to generate a new world (which isn't saying much when it already took over half a minute) there were no issues.
Also, I saw quite a few black spots around lava pools when looking around underground, so the lighting changes mentioned in later posts haven't fixed that issue; indeed, they always say it has been fixed in every release (no mention in the update notes in the launcher though).
*Yes, I actually modded 1.8 to make up for their gross incompetence in not allowing customizable cave (and other structures; see Superflat) generation in the customized world type, only an on/off setting:
Same cave in 1.8, note the different ores and lack of mineshafts (another thing nerfed in 1.7, but generating the same if the chance parameter is adjusted, haven't changed it yet):
Wow. That is incredibly disheartening. The game went from silky smooth to simply broken. The bug reports seem to indicate that they are oblivious to these problems and don't intend on fixing it? I finally found myself a friendly and mature realm and then this happens.