diff --git a/.circleci/config.yml b/.circleci/config.yml
index 38e9ee47f..c3e1c588b 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -366,6 +366,7 @@ defaults:
       environment: &base_archlinux_env
         TERM: xterm
         MAKEFLAGS: -j 3
+        CPUs: 3
 
   - base_archlinux_large: &base_archlinux_large
       <<: *base_archlinux
@@ -373,6 +374,7 @@ defaults:
       environment: &base_archlinux_large_env
         <<: *base_archlinux_env
         MAKEFLAGS: -j 5
+        CPUs: 5
 
   - base_cimg_small: &base_cimg_small
       docker:
@@ -381,6 +383,7 @@ defaults:
       environment: &base_cimg_small_env
         TERM: xterm
         MAKEFLAGS: -j 2
+        CPUs: 2
 
   - base_ems_large: &base_ems_large
       docker:
@@ -389,6 +392,7 @@ defaults:
       environment: &base_ems_large_env
         TERM: xterm
         MAKEFLAGS: -j 5
+        CPUs: 5
 
   - base_node_small: &base_node_small
       docker:
@@ -397,6 +401,7 @@ defaults:
       environment: &base_node_small_env
         TERM: xterm
         MAKEFLAGS: -j 2
+        CPUs: 2
 
   - base_osx: &base_osx
       macos:
@@ -405,6 +410,7 @@ defaults:
       environment: &base_osx_env
         TERM: xterm
         MAKEFLAGS: -j5
+        CPUs: 5
 
   - base_osx_large: &base_osx_large
       <<: *base_osx
@@ -412,6 +418,7 @@ defaults:
       environment: &base_osx_large_env
         <<: *base_osx_env
         MAKEFLAGS: -j10
+        CPUs: 10
 
   - base_python_small: &base_python_small
       docker:
@@ -420,6 +427,7 @@ defaults:
       environment: &base_python_small_env
         TERM: xterm
         MAKEFLAGS: -j 2
+        CPUs: 2
 
   - base_ubuntu_clang: &base_ubuntu_clang
       docker:
@@ -427,6 +435,7 @@ defaults:
       environment: &base_ubuntu_clang_env
         TERM: xterm
         MAKEFLAGS: -j 3
+        CPUs: 3
 
   - base_ubuntu_clang_small: &base_ubuntu_clang_small
       <<: *base_ubuntu_clang
@@ -434,6 +443,7 @@ defaults:
       environment: &base_ubuntu_clang_small_env
         <<: *base_ubuntu_clang_env
         MAKEFLAGS: -j 2
+        CPUs: 2
 
   - base_ubuntu2004: &base_ubuntu2004
       docker:
@@ -441,6 +451,7 @@ defaults:
       environment: &base_ubuntu2004_env
         TERM: xterm
         MAKEFLAGS: -j 3
+        CPUs: 3
 
   - base_ubuntu2004_small: &base_ubuntu2004_small
       <<: *base_ubuntu2004
@@ -448,6 +459,7 @@ defaults:
       environment: &base_ubuntu2004_small_env
         <<: *base_ubuntu2004_env
         MAKEFLAGS: -j 2
+        CPUs: 2
 
   - base_ubuntu2004_xlarge: &base_ubuntu2004_xlarge
       <<: *base_ubuntu2004
@@ -455,6 +467,7 @@ defaults:
       environment: &base_ubuntu2004_xlarge_env
         <<: *base_ubuntu2004_env
         MAKEFLAGS: -j 10
+        CPUs: 10
 
   - base_ubuntu2204: &base_ubuntu2204
       docker:
@@ -462,6 +475,7 @@ defaults:
       environment: &base_ubuntu2204_env
         TERM: xterm
         MAKEFLAGS: -j 3
+        CPUs: 3
 
   - base_ubuntu2204_clang: &base_ubuntu2204_clang
       docker:
@@ -471,6 +485,7 @@ defaults:
         CC: clang
         CXX: clang++
         MAKEFLAGS: -j 3
+        CPUs: 3
 
   - base_ubuntu2204_clang_large: &base_ubuntu2204_clang_large
       <<: *base_ubuntu2204_clang
@@ -478,6 +493,7 @@ defaults:
       environment: &base_ubuntu2204_clang_large_env
         <<: *base_ubuntu2204_clang_env
         MAKEFLAGS: -j 5
+        CPUs: 5
 
   - base_ubuntu2204_small: &base_ubuntu2204_small
       <<: *base_ubuntu2204
@@ -485,6 +501,7 @@ defaults:
       environment: &base_ubuntu2204_small_env
         <<: *base_ubuntu2204_env
         MAKEFLAGS: -j 2
+        CPUs: 2
 
   - base_ubuntu2204_large: &base_ubuntu2204_large
       <<: *base_ubuntu2204
@@ -492,6 +509,7 @@ defaults:
       environment: &base_ubuntu2204_large_env
         <<: *base_ubuntu2204_env
         MAKEFLAGS: -j 5
+        CPUs: 5
 
   - base_ubuntu2204_xlarge: &base_ubuntu2204_xlarge
       <<: *base_ubuntu2204
@@ -499,6 +517,7 @@ defaults:
       environment: &base_ubuntu2204_xlarge_env
         <<: *base_ubuntu2204_env
         MAKEFLAGS: -j 10
+        CPUs: 10
 
   - base_win: &base_win
       executor:
diff --git a/.circleci/soltest.sh b/.circleci/soltest.sh
index e350aa23d..488201bae 100755
--- a/.circleci/soltest.sh
+++ b/.circleci/soltest.sh
@@ -36,6 +36,7 @@ set -e
 
 OPTIMIZE=${OPTIMIZE:-"0"}
 EVM=${EVM:-"invalid"}
+CPUs=${CPUs:-3}
 REPODIR="$(realpath "$(dirname "$0")/..")"
 
 IFS=" " read -r -a BOOST_TEST_ARGS <<< "$BOOST_TEST_ARGS"
@@ -67,7 +68,6 @@ get_logfile_basename() {
 # long-running test cases are next to each other.
 CIRCLE_NODE_INDEX=$(((CIRCLE_NODE_INDEX + 23 * INDEX_SHIFT) % CIRCLE_NODE_TOTAL))
 
-CPUs=3
 PIDs=()
 for run in $(seq 0 $((CPUs - 1)))
 do