Lost Cities: Multithreaded

🚀 Next-Level Performance

Lost Cities: Multithreaded completely transforms the exploration of urban landscapes by eliminating the characteristic lags and stutters. The mod significantly speeds up world generation, allowing for smooth gameplay even in the most complex urban environments.

⚡ Key Advantages

• Instant generation: cities appear almost as fast as regular terrain
• Smooth exploration: no delays when entering new city areas
• Server optimization: reduced lags for all players in multiplayer
• Full multithreading support: utilizes all available processor cores
• Flexible power modes: choice between maximum performance and lower system impact

🔧 Technical Features

The mod fixes critical issues of the original Lost Cities:

• Eliminated crashes due to null blocks that caused sudden freezes
• Fixed vine generation issues affecting building appearance
• Resolved thread safety issues during parallel generation
• Optimized memory usage to prevent excessive resource consumption

🎮 Compatibility

• Minecraft 1.20.1 with Forge
• The Lost Cities 1.20-7.4.3 (latest version)
• Works with most modpacks and optimization mods
• Simple installation - just place in the mods folder

🌟 Addon Compatibility

The mod works excellently with Lost Cities addons like ChaosZPack! Compatibility testing has been conducted to ensure a seamless experience.

🔭 Breakthrough with Distant Horizons

BREAKTHROUGH: This mod allows Distant Horizons Multithreaded World Gen to work perfectly with Lost Cities! The problem with huge terrain gaps that made these mods incompatible is now FIXED! Enjoy stunning city views with unprecedented viewing distances.

📊 Real Performance

With Lost Cities: Multithreaded installed:

• Cities generate as fast as regular terrain
• Exploration continues without technical interruptions
• Building generation happens almost instantly
• Servers maintain stability even with multiple players exploring
• Performance improves on both powerful and modest PCs

The difference is immediately noticeable - what used to take seconds now appears in the blink of an eye!

🆕 Version 1.6.1 - DHPATCH (2025-08-27)

What changed:

• ✅ Removed incorrect behavior that tried to forcibly run part of LostCities generation on the server main thread
• 🐞 Added a small debug message (shown only with debug logging enabled) to help detect generation in worker threads

What was fixed:

• 🛑 Stopped the huge WARN/error spam that appeared when running with DistantHorizons (DH). The problem arose from rescheduling that lost DH's special generation context
• 🧰 Added small safety mechanisms (such as returning AIR or default stair shape) to prevent null pointer crashes

💬 Frequently Asked Questions

🔄 Can I add this mod to an existing Lost Cities world or server?

Absolutely! The mod can be added to existing worlds, although I recommend creating a backup first as this is still BETA. Version migrations (from V1.1.0-BETA to V1.5.0-BETAREVAMPED) have been personally tested, and the mod seamlessly adapts without losing functionality.

💾 Why has my world folder size increased?

Starting from V1.2.0-BETA, the mod stores calculated data in a cache folder (world/lcmultithreadingcache). With disk cache, this folder is now important for faster chunk loading and may grow over time, but is automatically cleaned if it becomes too large. Use /lcmultithreaded cache wipeDisk for manual cleaning.

🧮 Why does my RAM usage increase by ~100 MB?

The mod maintains a memory cache for recently generated content to significantly improve performance. Older data is moved to disk or removed automatically as memory fills up.

⏮️ Will there be compatibility with older versions of Lost Cities?

Currently no. Code differences between versions make compatibility challenging. Although I'm considering future support for 1.21.1, I don't plan to support older versions as this would require using older Java versions - essentially a complete rewrite of the mod.

🔧 Quick Commands

• /lcmultithreaded maxpower on|off [perma] - Set all thread pools to maximum system cores
• /lcmultithreaded lowpower on|off [perma] - Halve the number of threads for lower system impact
• /lcmultithreaded stats - Show detailed thread pool usage and task counts
• /lcmultithreaded cache stats|clear|wipeDisk|evict <radius> - Manage and inspect caches
• /lcmultithreaded help - List all available commands

👨‍💻 About the Author

Hi! I'm Admany, and I created this mod to solve the performance issues I encountered with The Lost Cities. I co-founded BlackRift Studios with my partner ChaosCraft_HD, and we're working together to create amazing mods for the Minecraft community.

This mod is my solution to the lag problems in Lost Cities. I wrote it from scratch without using McJty's code, which is why it will remain closed-source.

Big thanks to McJty for creating The Lost Cities in the first place - it's an amazing mod that just needed some performance optimization!