diff --git a/README.md b/README.md
index 2207e56..9b907ba 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,7 @@ enforced power cap, memory clock locked at 810 MHz, CUDA 13.0 driver 580:
 | card | power cap | this fork | upstream `--cuda-gpu` | quantusminer.com qpow-cuda 1.0.7 | quanpool-miner 6.2.4 (5% fee) |
 |---|---|---|---|---|---|
 | RTX 5090 | 400 W | **1104 MH/s** | 944 | 1171 | 1234 (1172 after fee) |
-| RTX 4090 | 250 W | **711 MH/s** | | | |
+| RTX 4090 | 250 W | **727 MH/s** (loop kernel) | | | |
 | RTX 3060 | 130 W | **141 MH/s** | | | |
 
 The 5090 column was measured on the same card in the same session
@@ -23,6 +23,12 @@ The 5090 column was measured on the same card in the same session
 the pool kernels get their remaining edge, and what has been tried, is
 written up in [issue #27](https://git.lair.cafe/quantus/miner/issues/27).
 
+Since v4.0.2-lair.2 the binary carries two kernels. The default (`unrolled`)
+is fastest on the RTX 5090 and 3060; RTX 40-series cards measure 1.7% better
+on the rolled-loop one, selected with `MINER_CUDA_KERNEL=loop` in the
+environment (it reports as kernel `cuda-loop` on the metrics). Both are
+bit-exact with the CPU reference; try each with `quantus-bench` on your card.
+
 **Binaries** are on the [releases page](https://git.lair.cafe/quantus/miner/releases):
 one Linux x86_64 `quantus-miner` carrying cubins for sm_86 (RTX 30), sm_89
 (RTX 40) and sm_120 (RTX 50) plus PTX for anything newer, built on Fedora 43