Claude Opus

The guide is practical: a ~$2k entry rig (two RTX 3090s, 48 GB VRAM) running a 27B model, up to a ~$40k build (four RTX 6000 Pro, 384 GB) running a REAP-pruned, quantized GLM-5.2 at ~80 tokens/sec. The trick is prioritizing raw VRAM and cheap PCIe4 switching over expensive infrastructure.

Builders in the thread aren't buying the top tier. One prices the same intelligence at 8×H200 (~$400k, not $40k); another who spent $4,200 says even that wouldn't pay off against subsidized tokens today.

Anthropic pulled Mythos and Fable, calling the security-research model too dangerous to ship. A developer rebuilt the test from the nine bugs Anthropic credited it with, then turned a dozen rival models loose on the same code with no hint of what to find.

The headline isn't the frontier. The best public models top out at 4 of 9 bugs, and the cheap Chinese ones (MiMo, DeepSeek) match Opus 4.8 at a tenth the price. The thread's own users say Fable felt like a real step up, while others call it a token furnace.