What's the longest any single biome in minecraft can be?

I've been traversing a Junglehills biome for over 10,000 spaces and I'm about to kill myself so I'm hopefully out of the jungle. My video card died and I only have the motherboards 128mb of RAM for video so its taking me many hours to get as far as I'm. Should I just kill my guy and lose the loot of atleast 10 temples plus maps from my home area and all diamond tools and armor?

Do you mean tallest biome? If so extreme hills or if you mean the longest biome then yes its jungle biome and as for escaping i would try going on the tallest tree and look on horizion for any land hope i helped.