out of memory and huge lag spikes

after about 1 minute of play, i'm getting game freezes, huge lag, sometimes it recovers sometimes it doesn't

on pressing f3 its showing that its not even using 512mb ram of the full 2048 allocated.

here is a snipet from the console window, it just starts streaming these lines repetadly

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[14:16:36 INFO]: Client> [14:16:36] [Client thread/ERROR]: ########## GL ERROR ##########
[14:16:36 INFO]: Client> [14:16:36] [Client thread/ERROR]: @ Post render
[14:16:36 INFO]: Client> [14:16:36] [Client thread/ERROR]: 1285: Out of memory
[14:16:37 INFO]: Client> [14:16:37] [Client thread/ERROR]: ########## GL ERROR ##########
[14:16:37 INFO]: Client> [14:16:37] [Client thread/ERROR]: @ Post render
[14:16:37 INFO]: Client> [14:16:37] [Client thread/ERROR]: 1285: Out of memory
[14:16:38 INFO]: Client> [14:16:38] [Client thread/ERROR]: ########## GL ERROR ##########
[14:16:38 INFO]: Client> [14:16:38] [Client thread/ERROR]: @ Post render
[14:16:38 INFO]: Client> [14:16:38] [Client thread/ERROR]: 1285: Out of memory
[14:16:41 INFO]: Client> [14:16:41] [Client thread/ERROR]: ########## GL ERROR ##########
[14:16:41 INFO]: Client> [14:16:41] [Client thread/ERROR]: @ Post render
[14:16:41 INFO]: Client> [14:16:41] [Client thread/ERROR]: 1285: Out of memory
[14:16:42 INFO]: Client> [14:16:42] [Client thread/ERROR]: ########## GL ERROR ##########
[14:16:42 INFO]: Client> [14:16:42] [Client thread/ERROR]: @ Post render
[14:16:42 INFO]: Client> [14:16:42] [Client thread/ERROR]: 1285: Out of memory
[14:16:43 INFO]: Client> [14:16:43] [Client thread/ERROR]: ########## GL ERROR ##########
[14:16:43 INFO]: Client> [14:16:43] [Client thread/ERROR]: @ Post render
[14:16:43 INFO]: Client> [14:16:43] [Client thread/ERROR]: 1285: Out of memory
[14:16:44 INFO]: Client> [14:16:44] [Client thread/ERROR]: ########## GL ERROR ##########
[14:16:44 INFO]: Client> [14:16:44] [Client thread/ERROR]: @ Post render
[14:16:44 INFO]: Client> [14:16:44] [Client thread/ERROR]: 1285: Out of memory
[14:16:45 INFO]: Client> [14:16:45] [Client thread/ERROR]: ########## GL ERROR ##########
[14:16:45 INFO]: Client> [14:16:45] [Client thread/ERROR]: @ Post render
[14:16:45 INFO]: Client> [14:16:45] [Client thread/ERROR]: 1285: Out of memory
[14:16:46 INFO]: Client> [14:16:46] [Client thread/ERROR]: ########## GL ERROR ##########
[14:16:46 INFO]: Client> [14:16:46] [Client thread/ERROR]: @ Post render
[14:16:46 INFO]: Client> [14:16:46] [Client thread/ERROR]: 1285: Out of memory
[14:16:47 INFO]: Client> [14:16:47] [Client thread/ERROR]: ########## GL ERROR ##########
[14:16:47 INFO]: Client> [14:16:47] [Client thread/ERROR]: @ Post render
[14:16:47 INFO]: Client> [14:16:47] [Client thread/ERROR]: 1285: Out of memory
[14:16:47 INFO]: Client> [14:16:47] [Client thread/ERROR]: ########## GL ERROR ##########
[14:16:47 INFO]: Client> [14:16:47] [Client thread/ERROR]: @ Post render
[14:16:47 INFO]: Client> [14:16:47] [Client thread/ERROR]: 1285: Out of memory
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