diff --git a/frameworks/zix-ws/.gitignore b/frameworks/zix-ws/.gitignore
new file mode 100644
index 000000000..595d20d1a
--- /dev/null
+++ b/frameworks/zix-ws/.gitignore
@@ -0,0 +1,4 @@
+.zig-cache
+zig-out
+zig-package
+vendor
diff --git a/frameworks/zix-ws/Dockerfile b/frameworks/zix-ws/Dockerfile
index 13da3e499..b5c27bebd 100644
--- a/frameworks/zix-ws/Dockerfile
+++ b/frameworks/zix-ws/Dockerfile
@@ -5,7 +5,7 @@ ARG RETRY=6
 ARG TARGETARCH
 ARG RETRY_DELAY=3
 ARG ZIG_VERSION=0.16.0
-ARG ZIX_VERSION=0.4.x-rc3
+ARG ZIX_VERSION=0.5.x-rc1
 RUN apk add --no-cache ca-certificates curl git tar xz
 
 RUN set -eu; \
@@ -19,15 +19,8 @@ RUN set -eu; \
     mv "/opt/zig-${ZIG_ARCH}-linux-${ZIG_VERSION}" /opt/zig
 ENV PATH="/opt/zig:${PATH}"
 
-# Vendor zix X.Y.Z, separate layer so source-only rebuilds skip the fetch.
-# The Http1 raw engine work this image needs (large-body drain plus the per-worker
-# response cache used by the /json endpoint) must be present on the X.Y.Z branch.
-# Four ordered attempts before giving up: curl the archive tarball from github then
-# codeberg, then a shallow git clone from github then codeberg. The github archive
-# redirects to codeload.github.com (which the benchmark runner may not resolve), so
-# curl can fall through to the codeberg tarball, and git clone talks to github.com
-# and codeberg.org directly as the deeper fallback. RETRY and RETRY_DELAY bound
-# every attempt.
+# Vendor zix ${ZIX_VERSION} in its own layer so source-only rebuilds skip the fetch. Tries curl
+# tarball then git clone, github before codeberg. RETRY / RETRY_DELAY bound every attempt.
 RUN set -eu; \
     fetch() { \
         rm -rf /src/vendor/zix; mkdir -p /src/vendor/zix; \
@@ -61,7 +54,7 @@ RUN set -eu; \
         amd64) ZIG_TARGET=x86_64-linux-musl; ZIG_CPU=x86_64_v3 ;; \
         arm64) ZIG_TARGET=aarch64-linux-musl; ZIG_CPU=baseline ;; \
     esac; \
-    zig build -Dtarget="${ZIG_TARGET}" -Dcpu="${ZIG_CPU}" --release=fast
+    zig build -Dtarget="${ZIG_TARGET}" -Dcpu="${ZIG_CPU}+aes+pclmul+adx" --release=fast
 
 FROM alpine:3.20
 COPY --from=build /src/zig-out/bin/zix-ws /zix-ws
diff --git a/frameworks/zix-ws/meta.json b/frameworks/zix-ws/meta.json
index aa33e4c45..e3380b649 100644
--- a/frameworks/zix-ws/meta.json
+++ b/frameworks/zix-ws/meta.json
@@ -2,9 +2,9 @@
   "display_name": "zix-ws",
   "language": "Zig",
   "type": "engine",
-  "engine": "zix",
-  "description": "Zig WebSocket echo server on the zix.Http1 raw engine (no std.http). Shared-nothing by design: each worker owns its own SO_REUSEPORT multishot accept, io_uring completion ring, and connections, with no shared state or locking across cores. The upgrade and echo are engine-owned: frames are read from a shared per-worker provided-buffer ring (an idle connection holds no buffer), and a pipelined burst is coalesced into one write.",
-  "repo": "https://codeberg.org/prothegee/zix",
+  "engine": "zix uring",
+  "description": "Zig WebSocket echo server on the zix.Http1 raw engine (no std.http). Shared-nothing: each worker owns its SO_REUSEPORT accept, io_uring loop, and connections. The upgrade and echo are engine-owned: frames are read from a per-worker buffer ring (an idle connection holds no buffer), and a pipelined burst is coalesced into one write.",
+  "repo": "https://github.com/prothegee/zix",
   "enabled": true,
   "tests": [
     "echo-ws",
diff --git a/frameworks/zix-ws/src/main.zig b/frameworks/zix-ws/src/main.zig
index 05adac321..a25aaf34c 100644
--- a/frameworks/zix-ws/src/main.zig
+++ b/frameworks/zix-ws/src/main.zig
@@ -1,16 +1,9 @@
 //! HttpArena: zix-ws
 //!
-//! zix HttpArena WebSocket entry point.
-//!
-//! Intent: demonstrate the engine-owned WebSocket path of zix.Http1 (EPOLL
-//! dispatch model) against the HttpArena echo and echo-pipeline suites.
-//!
-//! Design choices:
-//! - GET /ws upgrades, then zix.Http1.WebSocket.serve drives the echo loop
-//!   inside the engine: frames are echoed on readiness and a pipelined burst is
-//!   coalesced into a single write.
-//! - No response cache: echo is per-connection, not a broadcast fanout, so there
-//!   is nothing to precompute or share across connections.
+//! zix.Http1 engine-owned WebSocket (.URING) against the HttpArena echo and echo-pipeline suites.
+//! GET /ws upgrades, then WebSocket.serve drives the echo loop inside the engine (frames echoed on
+//! readiness, a pipelined burst coalesced into one write). No response cache: echo is per-connection,
+//! nothing to precompute or share.
 
 const std = @import("std");
 const zix = @import("zix");
@@ -22,12 +15,12 @@ const LISTEN_IP: []const u8 = "::";
 const DISPATCH_MODEL: zix.Http1.DispatchModel = .URING;
 const KERNEL_BACKLOG: u31 = 16 * 1024;
 
-/// Per-machine tuning profile (ADR-041 increment 5): .lean for the 12-thread /
-/// 32 GB dev box, .throughput for the 64-core / 251 GB competition box. Only the
-/// HTTP handshake recv buffer differs (the WS frame buffer is already 32 KiB).
-/// Select .throughput for the 64-core deployment.
+/// Per-machine tuning profile (ADR-041 incr 5): .lean for the 12-thread dev box, .throughput for
+/// the 64-core box. Under .URING the engine now honors ws_recv_buf (sizes conn.buf and the unmask
+/// scratch, independent of max_recv_buf), so a deep pipelined echo burst accumulates in one
+/// WS_RECV_BUF (32 KiB) buffer. max_recv_buf only sizes the brief HTTP handshake recv.
 const Profile = enum { lean, throughput };
-const PROFILE: Profile = .lean;
+const PROFILE: Profile = .throughput;
 
 const MAX_RECV_BUF: usize = switch (PROFILE) {
     .lean => 4 * 1024,