diff --git a/docker/Dockerfile.base b/docker/Dockerfile.base
index 6f0d1812..0b299d81 100644
--- a/docker/Dockerfile.base
+++ b/docker/Dockerfile.base
@@ -28,7 +28,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   libvulkan-dev \
   python3-numpy
 WORKDIR /root
-RUN git clone https://github.com/iqtlabs/gr-iqtlabs -b 1.0.70
+RUN git clone https://github.com/iqtlabs/gr-iqtlabs -b 1.0.71
 COPY --from=iqtlabs/gamutrf-vkfft:latest /root /root/gr-iqtlabs
 WORKDIR /root/gr-iqtlabs/build
 COPY --from=sigmf-builder /usr/local /usr/local
diff --git a/gamutrf/grscan.py b/gamutrf/grscan.py
index 49ddbe62..d3c7e9bc 100644
--- a/gamutrf/grscan.py
+++ b/gamutrf/grscan.py
@@ -37,6 +37,7 @@ def __init__(
         external_gps_server="",
         external_gps_server_port=8888,
         fft_batch_size=256,
+        fft_processor_affinity=0,
         freq_end=1e9,
         freq_start=100e6,
         gps_server="",
@@ -178,6 +179,7 @@ def __init__(
                 skip_tune_step,
                 tuning_ranges,
                 pretune,
+                fft_processor_affinity,
             )
             + self.get_db_blocks(nfft, samp_rate, scaling)
         )
@@ -348,6 +350,7 @@ def get_offload_fft_blocks(
         vkfft,
         fft_batch_size,
         nfft,
+        fft_processor_affinity,
     ):
         fft_block = None
         fft_roll = False
@@ -355,11 +358,15 @@ def get_offload_fft_blocks(
             fft_block = self.wavelearner.fft(int(fft_batch_size * nfft), nfft, True)
             fft_roll = True
         elif vkfft:
+            # VkFFT handles batches by using set_multiple_output(), so we do not need
+            # to wrap it.
             fft_block = self.iqtlabs.vkfft(fft_batch_size, nfft, True)
-        else:
             fft_batch_size = 1
+        else:
             fft_block = fft.fft_vcc(nfft, True, [], True, 1)
+            fft_batch_size = 1
         fft_block.set_thread_priority(99)
+        fft_block.set_processor_affinity([fft_processor_affinity])
 
         fft_blocks = [
             self.apply_window(nfft, fft_batch_size),
@@ -390,9 +397,13 @@ def get_fft_blocks(
         skip_tune_step,
         tuning_ranges,
         pretune,
+        fft_processor_affinity,
     ):
         fft_batch_size, fft_blocks = self.get_offload_fft_blocks(
-            vkfft, fft_batch_size, nfft
+            vkfft,
+            fft_batch_size,
+            nfft,
+            fft_processor_affinity,
         )
         self.retune_pre_fft = self.get_pretune_block(
             fft_batch_size,
diff --git a/gamutrf/scan.py b/gamutrf/scan.py
index c2cae37d..f079b725 100644
--- a/gamutrf/scan.py
+++ b/gamutrf/scan.py
@@ -314,6 +314,13 @@ def argument_parser():
         default=256,
         help="offload FFT batch size",
     )
+    parser.add_argument(
+        "--fft_processor_affinity",
+        dest="fft_processor_affinity",
+        type=int,
+        default=0,
+        help="FFT processor affinity",
+    )
     parser.add_argument(
         "--vkfft",
         dest="vkfft",