diff --git a/flow/BUILD.bazel b/flow/BUILD.bazel
index 3e42c9ba5c..823d19658e 100644
--- a/flow/BUILD.bazel
+++ b/flow/BUILD.bazel
@@ -1,5 +1,4 @@
 load("@bazel-orfs//:openroad.bzl", "orfs_flow")
-load("@rules_python//python:pip.bzl", "compile_pip_requirements")
 
 filegroup(
     name = "constraints-gcd",
@@ -101,158 +100,8 @@ orfs_flow(
     ]),
 )
 
-filegroup(
-    name = "mock-array-constraints",
-    srcs = [
-        "designs/asap7/mock-array/constraints.sdc",
-    ],
-    visibility = [":__subpackages__"],
-)
-
-filegroup(
-    name = "mock-array-io",
-    srcs = [
-        "designs/asap7/mock-array/io.tcl",
-    ],
-    data = [
-        "designs/src/mock-array/util.tcl",
-    ],
-    visibility = [":__subpackages__"],
-)
-
-MOCK_ARRAY_FLOORPLAN_PLACE = {
-    "PLACE_PINS_ARGS": "-annealing",
-    "IO_CONSTRAINTS": "$(location :mock-array-io)",
-    "PLACE_DENSITY": "0.30",
-    "DIE_AREA": "0 0 358.56 388.8",
-    "CORE_AREA": "2.16 2.16 356.40000000000003 386.64000000000004",
-    "MACRO_PLACE_HALO": "0 2.16",
-    "RTLMP_BOUNDARY_WT": "0",
-    "PDN_TCL": "$(PLATFORM_DIR)/openRoad/pdn/BLOCKS_grid_strategy.tcl",
-    "MACRO_HALO_X": "0.5",
-    "MACRO_HALO_Y": "0.5",
-    "MACRO_BLOCKAGE_HALO": "0",
-    "ADDITIONAL_FILES": "$(locations :mock-array-io)",
-}
-
-orfs_flow(
-    name = "MockArray",
-    macros = ["Element_generate_abstract"],
-    stage_arguments = {
-        "synth": {
-            "SDC_FILE": "$(location :mock-array-constraints)",
-        },
-        "floorplan": MOCK_ARRAY_FLOORPLAN_PLACE | {
-        },
-        "place": MOCK_ARRAY_FLOORPLAN_PLACE | {
-        },
-        "cts": {
-            "CTS_BUF_DISTANCE": "60",
-        },
-        "route": {
-            # works with 28 or more iterations as of writing, so give it a few more.
-            "GLOBAL_ROUTE_ARGS": "-congestion_iterations 40 -verbose",
-            # If this design isn't quickly done in detailed routing, something is wrong.
-            # At time of adding this option, only 12 iterations were needed for 0
-            # violations.
-            "DETAILED_ROUTE_ARGS": "-bottom_routing_layer M2 -top_routing_layer M7 -save_guide_updates -verbose 1 -droute_end_iter 15",
-            # since we are specifying DETAILED_ROUTE_ARGS, we need to communicate the
-            # same information to other stages in the flow.
-            "MIN_ROUTING_LAYER": "M2",
-            "MAX_ROUTING_LAYER": "M7",
-        },
-        "final": {
-            "GDS_ALLOW_EMPTY": "Element",
-            "PWR_NETS_VOLTAGEsS": "",
-            "GND_NETS_VOLTAGES": "",
-        },
-    },
-    stage_sources = {
-        "synth": all_sources + [":mock-array-constraints"] + [":mock-array-io"],
-        "floorplan": all_sources + [":mock-array-io"],
-        "place": all_sources + [":mock-array-io"],
-        "cts": all_sources,
-        "final": all_sources,
-    },
-    verilog_files = glob(include = ["designs/src/mock-array/*.v"]),
-)
-
-filegroup(
-    name = "mock-array-element-io",
-    srcs = [
-        "designs/asap7/mock-array/Element/io.tcl",
-    ],
-    data = [
-        "designs/src/mock-array/util.tcl",
-    ],
-    visibility = [":__subpackages__"],
-)
-
-MOCK_ARRAY_ELEMENT_FLOORPLAN_PLACE = {
-    "IO_CONSTRAINTS": "$(location :mock-array-element-io)",
-    "PLACE_PINS_ARGS": "-annealing",
-}
-
-MOCK_ARRAY_ELEMENT_ALL = {
-    "MOCK_ARRAY_ROWS": "8",
-    "MOCK_ARRAY_COLS": "8",
-}
-
-mock_array_all_sources = ["designs/src/mock-array/util.tcl"]
-
-orfs_flow(
-    name = "Element",
-    abstract_stage = "route",
-    arguments = {
-        "PLACE_DENSITY": "0.82",
-    },
-    stage_arguments = {
-        "synth": MOCK_ARRAY_ELEMENT_ALL | {
-            "SDC_FILE": "$(location :mock-array-constraints)",
-        },
-        "floorplan": MOCK_ARRAY_ELEMENT_ALL | MOCK_ARRAY_ELEMENT_FLOORPLAN_PLACE | {
-            "DIE_AREA": "0 0 43.2 43.2",
-            "CORE_AREA": "1.08 1.08 42.120000000000005 42.120000000000005",
-            "PDN_TCL": "$(PLATFORM_DIR)/openRoad/pdn/BLOCK_grid_strategy.tcl",
-        },
-        "place": MOCK_ARRAY_ELEMENT_ALL | MOCK_ARRAY_ELEMENT_FLOORPLAN_PLACE | {
-        },
-        "cts": MOCK_ARRAY_ELEMENT_ALL | {
-        },
-        "route": MOCK_ARRAY_ELEMENT_ALL | {
-            # If this design isn't quickly done in detailed routing, something is wrong.
-            # At time of adding this option, only 3 iterations were needed for 0
-            # violations.
-            "DETAILED_ROUTE_ARGS": "-bottom_routing_layer M2 -top_routing_layer M5 -save_guide_updates -verbose 1 -droute_end_iter 10",
-            # since we are specifying DETAILED_ROUTE_ARGS, we need to communicate the
-            # same information to other stages in the flow.
-            "MIN_ROUTING_LAYER": "M2",
-            "MAX_ROUTING_LAYER": "M5",
-        },
-        "final": MOCK_ARRAY_ELEMENT_ALL | {
-            "PWR_NETS_VOLTAGES": "",
-            "GND_NETS_VOLTAGES": "",
-        },
-    },
-    stage_sources = {
-        "synth": mock_array_all_sources + [":mock-array-constraints"],
-        "floorplan": mock_array_all_sources + [":mock-array-element-io"],
-        "place": mock_array_all_sources + [":mock-array-element-io"],
-        "cts": mock_array_all_sources,
-        "route": mock_array_all_sources,
-        "final": mock_array_all_sources,
-    },
-    verilog_files = glob(include = ["designs/src/mock-array/*.v"]),
-)
-
 filegroup(
     name = "ethmac_lvt_src",
     srcs = glob(include = ["designs/src/ethmac_lvt/*.v"]),
     visibility = [":__subpackages__"],
 )
-
-compile_pip_requirements(
-    name = "requirements",
-    src = "util/requirements.in",
-    requirements_txt = "util/requirements_lock.txt",
-)
diff --git a/flow/designs/asap7/ethmac_lvt/BUILD.bazel b/flow/designs/asap7/ethmac_lvt/BUILD.bazel
new file mode 100644
index 0000000000..a0abaeeaaf
--- /dev/null
+++ b/flow/designs/asap7/ethmac_lvt/BUILD.bazel
@@ -0,0 +1,59 @@
+load("@bazel-orfs//:sweep.bzl", "orfs_sweep")
+load("//util:plot_congestion.bzl", "plot_congestion")
+
+# Format densities, rounding to 2 decimal places.
+SWEEPS = {
+    "PLACE_DENSITY": [str(0.60 + x * 0.01 + 0.005)[:4] for x in range(20)],
+    "CORE_UTILIZATION": [str(40 + x * 5) for x in range(4)],
+}
+
+SWEEP = "PLACE_DENSITY"
+
+orfs_sweep(
+    name = "ethmac_lvt",
+    arguments = {
+        # Faster builds
+        "SKIP_INCREMENTAL_REPAIR": "1",
+        "GPL_TIMING_DRIVEN": "0",
+        # Various
+        "SDC_FILE": "$(location :constraint.sdc)",
+        "ABC_AREA": "1",
+        "CORE_UTILIZATION": "40",
+        "CORE_ASPECT_RATIO": "1",
+        "CORE_MARGIN": "2",
+        "PLACE_DENSITY": "0.60",
+        "ASAP7_USELVT": "1",
+        "RECOVER_POWER": "1",
+        "ADDITIONAL_LIBS": "$(LIB_DIR)/asap7sc7p5t_AO_RVT_FF_nldm_211120.lib.gz \
+                                $(LIB_DIR)/asap7sc7p5t_INVBUF_RVT_FF_nldm_220122.lib.gz \
+			        $(LIB_DIR)/asap7sc7p5t_OA_RVT_FF_nldm_211120.lib.gz \
+			        $(LIB_DIR)/asap7sc7p5t_SIMPLE_RVT_FF_nldm_211120.lib.gz \
+			        $(LIB_DIR)/asap7sc7p5t_SEQ_RVT_FF_nldm_220123.lib",
+        "ADDITIONAL_GDS": "$(PLATFORM_DIR)/gds/asap7sc7p5t_28_R_220121a.gds",
+        "ADDITIONAL_LEFS": "$(PLATFORM_DIR)/lef/asap7sc7p5t_28_R_1x_220121a.lef",
+    },
+    other_variants = {"base": {}},
+    sources = {
+        "SDC_FILE": [":constraint.sdc"],
+    },
+    sweep = {
+        value: {
+            "arguments": {
+                SWEEP: value,
+            },
+            "previous_stage": {
+                "floorplan": "ethmac_lvt_synth",
+            },
+        }
+        for value in SWEEPS[SWEEP]
+    },
+    top = "ethmac",
+    verilog_files = ["//:ethmac_lvt_src"],
+)
+
+plot_congestion(
+    name = "plot",
+    srcs = [":ethmac_lvt_{value}_grt".format(value = value) for value in SWEEPS[SWEEP]],
+    argument = SWEEP,
+    values = SWEEPS[SWEEP],
+)
diff --git a/flow/designs/asap7/mock-array/BUILD.bazel b/flow/designs/asap7/mock-array/BUILD.bazel
new file mode 100644
index 0000000000..0c14955475
--- /dev/null
+++ b/flow/designs/asap7/mock-array/BUILD.bazel
@@ -0,0 +1,122 @@
+load("@bazel-orfs//:openroad.bzl", "orfs_flow")
+load("@bazel-orfs//:sweep.bzl", "orfs_sweep")
+load("//util:plot_congestion.bzl", "plot_congestion")
+
+# Format densities, rounding to 2 decimal places.
+SWEEPS = {
+    "PLACE_DENSITY": [str(0.82 + x * 0.01 + 0.005)[:4] for x in range(10)],
+}
+
+SWEEP = "PLACE_DENSITY"
+
+filegroup(
+    name = "mock-array-constraints",
+    srcs = [
+        "constraints.sdc",
+    ],
+    visibility = [":__subpackages__"],
+)
+
+filegroup(
+    name = "mock-array-io",
+    srcs = [
+        "io.tcl",
+    ],
+    data = [
+        "//designs/src/mock-array:util.tcl",
+    ],
+    visibility = [":__subpackages__"],
+)
+
+orfs_flow(
+    name = "MockArray",
+    arguments = {
+        "PLACE_PINS_ARGS": "-annealing",
+        "IO_CONSTRAINTS": "$(location :mock-array-io)",
+        "PLACE_DENSITY": "0.30",
+        "DIE_AREA": "0 0 358.56 388.8",
+        "CORE_AREA": "2.16 2.16 356.40000000000003 386.64000000000004",
+        "MACRO_PLACE_HALO": "0 2.16",
+        "RTLMP_BOUNDARY_WT": "0",
+        "PDN_TCL": "$(PLATFORM_DIR)/openRoad/pdn/BLOCKS_grid_strategy.tcl",
+        "MACRO_HALO_X": "0.5",
+        "MACRO_HALO_Y": "0.5",
+        "MACRO_BLOCKAGE_HALO": "0",
+        "SDC_FILE": "$(location :mock-array-constraints)",
+        "MAX_ROUTING_LAYER": "M9",
+        "GDS_ALLOW_EMPTY": "Element",
+        "PWR_NETS_VOLTAGEsS": "",
+        "GND_NETS_VOLTAGES": "",
+    },
+    macros = ["Element_generate_abstract"],
+    stage_sources = {
+        "synth": [":mock-array-constraints"] + [":mock-array-io"],
+        "floorplan": [":mock-array-io"],
+        "place": [":mock-array-io"],
+    },
+    verilog_files = ["//designs/src/mock-array:verilog"],
+)
+
+filegroup(
+    name = "mock-array-element-io",
+    srcs = [
+        "Element/io.tcl",
+    ],
+    data = [
+        "//designs/src/mock-array:util.tcl",
+    ],
+    visibility = [":__subpackages__"],
+)
+
+mock_array_all_sources = ["//designs/src/mock-array:util.tcl"]
+
+orfs_sweep(
+    name = "Element",
+    abstract_stage = "route",
+    arguments = {
+        "PLACE_DENSITY": "0.82",
+        "MOCK_ARRAY_ROWS": "8",
+        "MOCK_ARRAY_COLS": "8",
+        "DETAILED_ROUTE_END_ITERATION": "6",
+        "MIN_ROUTING_LAYER": "M2",
+        "MAX_ROUTING_LAYER": "M5",
+        "IO_PLACER_H": "M2 M4",
+        "IO_PLACER_V": "M3 M5",
+        "PLACE_PINS_ARGS": "-annealing",
+        "GND_NETS_VOLTAGES": "",
+        "PWR_NETS_VOLTAGES": "",
+        "SDC_FILE": "$(location :mock-array-constraints)",
+        "IO_CONSTRAINTS": "$(location :mock-array-element-io)",
+        "DIE_AREA": "0 0 43.2 43.2",
+        "CORE_AREA": "1.08 1.08 42.120000000000005 42.120000000000005",
+        "PDN_TCL": "$(PLATFORM_DIR)/openRoad/pdn/BLOCK_grid_strategy.tcl",
+    },
+    other_variants = {"base": {}},
+    stage_sources = {
+        "synth": mock_array_all_sources + [":mock-array-constraints"],
+        "floorplan": mock_array_all_sources + [":mock-array-element-io"],
+        "place": mock_array_all_sources + [":mock-array-element-io"],
+        "cts": mock_array_all_sources,
+        "route": mock_array_all_sources,
+        "final": mock_array_all_sources,
+    },
+    sweep = {
+        value: {
+            "arguments": {
+                SWEEP: value,
+            },
+            "previous_stage": {
+                "floorplan": "Element_synth",
+            },
+        }
+        for value in SWEEPS[SWEEP]
+    },
+    verilog_files = ["//designs/src/mock-array:verilog"],
+)
+
+plot_congestion(
+    name = "plot",
+    srcs = [":Element_{value}_grt".format(value = value) for value in SWEEPS[SWEEP]],
+    argument = SWEEP,
+    values = SWEEPS[SWEEP],
+)
diff --git a/flow/designs/src/mock-array/BUILD.bazel b/flow/designs/src/mock-array/BUILD.bazel
new file mode 100644
index 0000000000..fc10b865c2
--- /dev/null
+++ b/flow/designs/src/mock-array/BUILD.bazel
@@ -0,0 +1,7 @@
+exports_files(["util.tcl"] + glob(["*.v"]))
+
+filegroup(
+    name = "verilog",
+    srcs = glob(["*.v"]),
+    visibility = ["//visibility:public"],
+)
diff --git a/flow/util/BUILD.bazel b/flow/util/BUILD.bazel
new file mode 100644
index 0000000000..b5b9d74a0c
--- /dev/null
+++ b/flow/util/BUILD.bazel
@@ -0,0 +1,18 @@
+load("@orfs-pip//:requirements.bzl", "requirement")
+load("@rules_python//python:pip.bzl", "compile_pip_requirements")
+
+exports_files(["open_plots.sh"])
+
+py_binary(
+    name = "plot_congestion",
+    srcs = ["plot_congestion.py"],
+    main = "plot_congestion.py",
+    visibility = ["//visibility:public"],
+    deps = [requirement("matplotlib")],
+)
+
+compile_pip_requirements(
+    name = "requirements",
+    src = "requirements.in",
+    requirements_txt = "requirements_lock.txt",
+)
diff --git a/flow/util/open_plots.sh b/flow/util/open_plots.sh
new file mode 100755
index 0000000000..b7fe40d779
--- /dev/null
+++ b/flow/util/open_plots.sh
@@ -0,0 +1,2 @@
+#!/bin/bash
+xdg-open $1
diff --git a/flow/util/plot_congestion.bzl b/flow/util/plot_congestion.bzl
new file mode 100644
index 0000000000..0266febbc3
--- /dev/null
+++ b/flow/util/plot_congestion.bzl
@@ -0,0 +1,23 @@
+"""Plots congestion against some parameter such as PLACE_DENSITY"""
+
+def plot_congestion(name, srcs, argument, values):
+    native.filegroup(
+        name = "{name}_congestion".format(name = name),
+        srcs = srcs,
+        output_group = "congestion.rpt",
+    )
+
+    native.genrule(
+        name = "{}_pdf".format(name),
+        srcs = ["{name}_congestion".format(name = name)],
+        outs = ["{}.pdf".format(name)],
+        cmd = "$(execpath //util:plot_congestion) {argument} $@ $(locations :{name}_congestion) {values}".format(values = " ".join(values), argument = argument, name = name),
+        tools = ["//util:plot_congestion"],
+    )
+
+    native.sh_binary(
+        name = name,
+        srcs = ["//util:open_plots.sh"],
+        args = ["$(location :{}.pdf)".format(name)],
+        data = ["{}.pdf".format(name)],
+    )
diff --git a/flow/util/plot_congestion.py b/flow/util/plot_congestion.py
new file mode 100644
index 0000000000..da6ce3056b
--- /dev/null
+++ b/flow/util/plot_congestion.py
@@ -0,0 +1,31 @@
+import matplotlib.pyplot as plt
+import numpy as np
+import sys
+import re
+import os
+
+
+sweep = sys.argv[1]
+output = sys.argv[2]
+remainder = sys.argv[3:]
+files = remainder[: len(remainder) // 2]
+values = remainder[len(remainder) // 2 :]
+
+# count lines in each file and divide by 3 and create a list of those
+# numbers
+congestion = []
+for file in files:
+    with open(file, "r") as f:
+        lines = f.readlines()
+        congestion.append(len(lines) // 4)
+
+# xy plot of density vs DRC errors
+x = list(map(float, values))
+y = congestion
+plt.plot(x, y, "o-")
+plt.xlabel(sweep)
+plt.ylabel("DRC Errors")
+plt.title(sweep + " vs DRC Errors")
+plt.grid()
+plt.yscale("log")
+plt.savefig(output)