Massive amount of Heap used when opening a world - NVidia issue ?

---- Minecraft Crash Report ----
// My bad.

Time: 10/10/15 7:32 PM
Description: Unexpected error

java.lang.NullPointerException: Unexpected error
	at ahc.a(SourceFile:1118)
	at bku.h(SourceFile:1602)
	at bku.a(SourceFile:1178)
	at bku.b(SourceFile:1163)
	at bku.a(SourceFile:1010)
	at bab.as(SourceFile:957)
	at bab.a(SourceFile:379)
	at net.minecraft.client.main.Main.main(SourceFile:125)


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- Head --
Stacktrace:
	at ahc.a(SourceFile:1118)
	at bku.h(SourceFile:1602)
	at bku.a(SourceFile:1178)
	at bku.b(SourceFile:1163)

-- Affected level --
Details:
	Level name: MpServer
	All players: 0 total; []
	Chunk stats: MultiplayerChunkCache: 0, 0
	Level seed: 0
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: World: (8,64,8), Chunk: (at 8,4,8 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 0 game time, 0 day time
	Level dimension: 0
	Level storage version: 0x00000 - Unknown?
	Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: false
	Forced entities: 0 total; []
	Retry entities: 0 total; []
	Server brand: ~~ERROR~~ NullPointerException: null
	Server type: Integrated singleplayer server
Stacktrace:
	at bii.a(SourceFile:362)
	at bab.b(SourceFile:2389)
	at bab.a(SourceFile:393)
	at net.minecraft.client.main.Main.main(SourceFile:125)

-- System Details --
Details:
	Minecraft Version: 15w41b
	Operating System: Windows 10 (amd64) version 10.0
	Java Version: 1.8.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 2170248 bytes (2 MB) / 1060372480 bytes (1011 MB) up to 1060372480 bytes (1011 MB)
	JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 15w41b
	LWJGL: 2.9.4
	OpenGL: GeForce GT 610/PCIe/SSE2 GL version 4.5.0 NVIDIA 353.62, NVIDIA Corporation
	GL Caps: Using GL 1.3 multitexturing.
Using GL 1.3 texture combiners.
Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported.
Shaders are available because OpenGL 2.1 is supported.
VBOs are available because OpenGL 1.5 is supported.

	Using VBOs: No
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Packs: 
	Current Language: English (US)
	Profiler Position: N/A (disabled)
	CPU: 4x AMD FX(tm)-4130 Quad-Core Processor