I don't have a way to do it, but I'm entirely sure the issue is caused by the XP orbs. I just tested this with a fully repaired pickaxe and the issue is gone. Either XP orbs hitboxes interrupt the mining or the repair animation. Damaged pickaxes have this issue.
Here's the video of what's happening.
You can clearly see that the mining is interrupted quite often. The pickaxe is enchanted with Efficiency 4, Unbreaking 3, Fortune 3 and Mending.
I'm assuming that XP orbs that float towards the player do this, as would any other entity, but I might be wrong.
I've attached the debug profile.
Like I said, I'm mining nether quartz ore which cannot be insta-mined.
It propably was when the recipe used shovels, but it doesn't anymore.
That was always the case.
Yes, I made my assumptions too quickly, but there's still something odd about durability. I updated the description.
I tried chickens, cows and pigs.
@unknown I completely forgot about this report, but as long as it's working towards solving the issue I don't have any problems with that.
I encountered one skeleton with no AI, but it spawned naturally as well. I managed to hit him once, then he froze.
15w39a brings my FPS to what it is in 1.8, but I'm pretty sure the issue is still there as the new chunk rendering method supposedly fixes a bug from 1.8 whereas this has been happening since 1.9 snapshots.
No difference in 15w38a for me.
In 15w37a it's even worse. CPU sits at just a few % but any system response (switching windows for example) takes around 2 - 3 seconds while the game's running.
The only thing that has changed is that forcing VSync to off in GPU settings does nothing to display_update now. It grows constantly. Framerate will go up if I look down, but not by a lot, from 30 to 41FPS where in 1.8 even if I would have 10FPS looking straight, I'd get at least 100 by looking on the ground.
No change in 15w36a.
@unknown you've posted a crash report from 1.8.8.
That's because the game uses it's own version of Java downloaded through the launcher. It's all fine.
15w35c is still affected. Someone update this.
So apparently display_update stands for VSync, but I have it turned off. When I force it to off in nVidia panel then a thing called "unspecified" takes the same percentage of resources over time. I attached another screenshot.
And this is what my console output looks like:
[03:41:26] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 146.370306 ms
[03:41:26] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 156.311026 ms
[03:41:26] [Client thread/WARN]: Something's taking too long! 'root' took aprox 167.279473 ms
[03:41:28] [Client thread/WARN]: Something's taking too long! 'root' took aprox 727.807112 ms
[03:41:28] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 289.797575 ms
[03:41:28] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 334.59543 ms
[03:41:28] [Client thread/WARN]: Something's taking too long! 'root' took aprox 371.302748 ms
[03:41:30] [Client thread/WARN]: Something's taking too long! 'root' took aprox 921.119725 ms
[03:41:30] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 101.721119 ms
[03:41:30] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 129.507942 ms
[03:41:30] [Client thread/WARN]: Something's taking too long! 'root' took aprox 188.900615 ms
[03:41:31] [Client thread/WARN]: Something's taking too long! 'root' took aprox 535.207838 ms
[03:41:31] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 182.441346 ms
[03:41:31] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 223.815719 ms
[03:41:31] [Client thread/WARN]: Something's taking too long! 'root' took aprox 232.107096 ms
[03:41:33] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer.level.camera' took aprox 112.880517 ms
[03:41:33] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer.level' took aprox 129.48271 ms
[03:41:33] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer' took aprox 136.533928 ms
[03:41:33] [Client thread/WARN]: Something's taking too long! 'root' took aprox 142.164262 ms
[03:41:34] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 440.217412 ms
[03:41:34] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 483.291591 ms
[03:41:34] [Client thread/WARN]: Something's taking too long! 'root' took aprox 542.055147 ms
[03:41:34] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 332.287307 ms
[03:41:34] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 348.172749 ms
[03:41:34] [Client thread/WARN]: Something's taking too long! 'root' took aprox 373.847174 ms
[03:41:34] [Client thread/WARN]: Something's taking too long! 'root' took aprox 113.372558 ms
[03:41:35] [Client thread/WARN]: Something's taking too long! 'root' took aprox 112.272542 ms
[03:41:36] [Client thread/WARN]: Something's taking too long! 'root' took aprox 352.055198 ms
[03:41:37] [Client thread/WARN]: Something's taking too long! 'root' took aprox 111.471228 ms
[03:41:37] [Client thread/WARN]: Something's taking too long! 'root' took aprox 421.73128 ms
[03:41:37] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 139.024819 ms
[03:41:37] [Client thread/WARN]: Something's taking too long! 'root' took aprox 153.430048 ms
[03:41:38] [Client thread/WARN]: Something's taking too long! 'root' took aprox 303.69576 ms
[03:41:38] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 151.867657 ms
[03:41:38] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 184.936671 ms
[03:41:38] [Client thread/WARN]: Something's taking too long! 'root' took aprox 215.433979 ms
[03:41:39] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer.gui' took aprox 269.841459 ms
[03:41:39] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer' took aprox 298.479039 ms
[03:41:39] [Client thread/WARN]: Something's taking too long! 'root' took aprox 301.170429 ms
[03:41:39] [Client thread/WARN]: Something's taking too long! 'root' took aprox 167.009413 ms
[03:41:40] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 740.723262 ms
[03:41:40] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 752.993247 ms
[03:41:40] [Client thread/WARN]: Something's taking too long! 'root' took aprox 814.523892 ms
[03:41:40] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer.gui.debug' took aprox 334.677267 ms
[03:41:40] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer.gui' took aprox 336.1435 ms
[03:41:40] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer' took aprox 341.015485 ms
[03:41:40] [Client thread/WARN]: Something's taking too long! 'root' took aprox 372.132704 ms
[03:41:42] [Client thread/WARN]: Something's taking too long! 'root' took aprox 205.756158 ms
[03:41:42] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer.level.camera' took aprox 165.906669 ms
[03:41:42] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer.level' took aprox 180.695506 ms
[03:41:42] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer' took aprox 184.91212 ms
[03:41:42] [Client thread/WARN]: Something's taking too long! 'root' took aprox 185.509866 ms
[03:41:43] [Client thread/WARN]: Something's taking too long! 'root' took aprox 101.57245 ms
[03:41:44] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 1071.586959 ms
[03:41:44] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 1089.018425 ms
[03:41:44] [Client thread/WARN]: Something's taking too long! 'root' took aprox 1129.658658 ms
[03:41:44] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 167.127394 ms
[03:41:44] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 169.695006 ms
[03:41:44] [Client thread/WARN]: Something's taking too long! 'root' took aprox 192.431509 ms
[03:41:45] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 100.524263 ms
[03:41:45] [Client thread/WARN]: Something's taking too long! 'root' took aprox 121.554139 ms
[03:41:46] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 411.174742 ms
[03:41:46] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 421.326531 ms
[03:41:46] [Client thread/WARN]: Something's taking too long! 'root' took aprox 440.670239 ms
[03:41:46] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 106.642206 ms
[03:41:46] [Client thread/WARN]: Something's taking too long! 'root' took aprox 113.324479 ms
[03:41:47] [Client thread/WARN]: Something's taking too long! 'root' took aprox 951.62249 ms
[03:41:47] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 110.193219 ms
[03:41:47] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 112.610457 ms
[03:41:47] [Client thread/WARN]: Something's taking too long! 'root' took aprox 120.9656 ms
[03:41:50] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 1024.193188 ms
[03:41:50] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 1028.102916 ms
[03:41:50] [Client thread/WARN]: Something's taking too long! 'root' took aprox 1086.756675 ms
[03:41:51] [Client thread/WARN]: Something's taking too long! 'root' took aprox 328.50954 ms
[03:41:52] [Client thread/WARN]: Something's taking too long! 'root' took aprox 551.296849 ms
[03:41:52] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 872.762673 ms
[03:41:52] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 909.616273 ms
[03:41:52] [Client thread/WARN]: Something's taking too long! 'root' took aprox 919.407641 ms
[03:41:53] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 120.958439 ms
[03:41:53] [Client thread/WARN]: Something's taking too long! 'root' took aprox 138.951166 ms
[03:41:55] [Client thread/WARN]: Something's taking too long! 'root' took aprox 569.801053 ms
[03:41:56] [Client thread/WARN]: Something's taking too long! 'root' took aprox 101.165996 ms
[03:41:57] [Client thread/WARN]: Something's taking too long! 'root' took aprox 370.249107 ms
[03:41:58] [Client thread/WARN]: Something's taking too long! 'root' took aprox 100.67532 ms
[03:42:00] [Client thread/WARN]: Something's taking too long! 'root' took aprox 151.114763 ms
[03:42:03] [Client thread/WARN]: Something's taking too long! 'root' took aprox 121.24998 ms
[03:42:04] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer.gui' took aprox 119.236467 ms
[03:42:04] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer' took aprox 145.999655 ms
[03:42:04] [Client thread/WARN]: Something's taking too long! 'root' took aprox 146.234253 ms
[03:42:07] [Client thread/WARN]: Something's taking too long! 'root' took aprox 100.892868 ms
[03:42:08] [Client thread/WARN]: Something's taking too long! 'root' took aprox 107.069119 ms
[03:42:13] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer.gui.debug' took aprox 516.168971 ms
[03:42:13] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer.gui' took aprox 541.920118 ms
[03:42:13] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer' took aprox 552.996656 ms
[03:42:13] [Client thread/WARN]: Something's taking too long! 'root' took aprox 555.807732 ms
[03:42:13] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 185.540895 ms
[03:42:13] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 299.165441 ms
[03:42:13] [Client thread/WARN]: Something's taking too long! 'root' took aprox 331.442006 ms
[03:42:13] [Client thread/WARN]: Something's taking too long! 'root' took aprox 163.002845 ms
[03:42:14] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 399.884747 ms
[03:42:14] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 408.588716 ms
[03:42:14] [Client thread/WARN]: Something's taking too long! 'root' took aprox 480.342416 ms
[03:42:15] [Client thread/WARN]: Something's taking too long! 'root' took aprox 247.529482 ms
[03:42:15] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 135.635774 ms
[03:42:15] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 171.530867 ms
[03:42:15] [Client thread/WARN]: Something's taking too long! 'root' took aprox 188.660562 ms
[03:42:15] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 160.04651 ms
[03:42:15] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 164.580581 ms
[03:42:15] [Client thread/WARN]: Something's taking too long! 'root' took aprox 187.164322 ms
[03:42:16] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer.level.entities.entities' took aprox 143.433407 ms
[03:42:16] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer.level.entities' took aprox 149.15683 ms
[03:42:16] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer.level' took aprox 152.000982 ms
[03:42:16] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer' took aprox 158.920239 ms
[03:42:16] [Client thread/WARN]: Something's taking too long! 'root' took aprox 162.254044 ms
[03:42:17] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer.level.culling' took aprox 170.485068 ms
[03:42:17] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer.level' took aprox 200.666284 ms
[03:42:17] [Client thread/WARN]: Something's taking too long! 'root.gameRenderer' took aprox 203.500887 ms
[03:42:17] [Client thread/WARN]: Something's taking too long! 'root' took aprox 233.654484 ms
[03:42:18] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 591.218287 ms
[03:42:18] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 600.864736 ms
[03:42:18] [Client thread/WARN]: Something's taking too long! 'root' took aprox 612.906603 ms
[03:42:20] [Client thread/WARN]: Something's taking too long! 'root' took aprox 288.755526 ms
[03:42:21] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 278.723763 ms
[03:42:21] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 291.541369 ms
[03:42:21] [Client thread/WARN]: Something's taking too long! 'root' took aprox 299.563028 ms
[03:42:22] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 232.080159 ms
[03:42:22] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 245.717832 ms
[03:42:22] [Client thread/WARN]: Something's taking too long! 'root' took aprox 270.698694 ms
[03:42:28] [Client thread/WARN]: Something's taking too long! 'root' took aprox 335.501767 ms
[03:42:28] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 177.682227 ms
[03:42:28] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 186.837318 ms
[03:42:28] [Client thread/WARN]: Something's taking too long! 'root' took aprox 194.740996 ms
[03:42:31] [Client thread/WARN]: Something's taking too long! 'root' took aprox 124.38431 ms
[03:42:32] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 297.492912 ms
[03:42:32] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 308.283706 ms
[03:42:32] [Client thread/WARN]: Something's taking too long! 'root' took aprox 318.134406 ms
[03:42:33] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 396.665854 ms
[03:42:33] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 406.058271 ms
[03:42:33] [Client thread/WARN]: Something's taking too long! 'root' took aprox 444.122366 ms
[03:42:40] [Client thread/WARN]: Something's taking too long! 'root' took aprox 498.940391 ms
[03:42:40] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 134.335601 ms
[03:42:40] [Client thread/WARN]: Something's taking too long! 'root' took aprox 142.532526 ms
[03:42:42] [Client thread/WARN]: Something's taking too long! 'root.tick.textures' took aprox 942.785536 ms
[03:42:42] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 989.316616 ms
[03:42:42] [Client thread/WARN]: Something's taking too long! 'root' took aprox 1024.812416 ms
[03:42:44] [Client thread/WARN]: Something's taking too long! 'root' took aprox 104.226332 ms
In fact, this issue is also present in 1.15.2. Repairing with XP puts down the tool for a split second and seems to cancel the mining process, but it is most prominent when you're mining blocks in different spots, switching from one spot to another. If you try to mine, let's say, a straight line of blocks in front of you, it does not happen.
It's as if the repair animation was taking the priority over mining when you're not quick enough switching focus from one block to another.