I ' m from Carlisle near the Lake District in the UK <| sep |> Lmao that ' s a wierd one eggs dee <| sep |> I have yet to see actual data including profiling output on Fastcraft slowing the game down , although the general phenomenon is possible from corner cases my heuristics don ' t handle well . As far as I ' m concerned this is just FUD based on incorrect assessments and without trying to actually help investigating and solving the issues . Whenever I ' m investigating such a case the problem suddenly doesn ' t present itself anymore . The goal of the mod is not to improve the steady state frame rate of everyone , especially with Nvidia ' s drivers or conflicting mods . However even then it still makes a difference in actual game play to lessen or get rid of lag spikes . Worlds usually load much quicker with just FC than with Vanilla , Optifine or OptifineFC combined . Fastcraft is effectively about as open about its inner workings as Optifine if you look more closely . It obviously doesn ' t have a blog to elaborate on some features , there isn ' t much value in writing that something just has been reimplemented properly to be efficient , but I have elaborated on various details in random posts . Forge is not a suitable platform for FC , they don ' t even have the engineering resources to maintain their own existing code base properly . Neither am I willing to hand my work over to a commercial project backed by a forprofit company and ad gateways . The Forge distributions aren ' t open source per the OSI definition due to proprietary MCP data and they employ equally proprietary toolsprocesses for generating said data . Foamfix reduces memory use from redundant objects by deduplicating or removing them . This is one of the aspects FastCraft tweaks as well , but of course in 1 . 7 Forge was a lot less bloated in regards to wasting memory than it is today . If someone ' s on the edge of being able to start the game due to lack of memory , the mod will give enough headroom to play without as much GC lag or being able to launch in the first place . Having less objects may also help everyone else due to resulting faster old gen garbage collection , but the effect is likely to be insignificant .