diff --git a/MozillaFirefox.changes b/MozillaFirefox.changes
index fe66963..9e37a70 100644
--- a/MozillaFirefox.changes
+++ b/MozillaFirefox.changes
@@ -1,3 +1,18 @@
+-------------------------------------------------------------------
+Sun Jan 30 23:58:34 UTC 2022 - Dirk Müller <dmueller@suse.com>
+
+- disable ccache, this adds about 1 minute of build time and 
+  over 2 GB of disk space usage without benefit on OBS builds
+- build with rust-simd like upstream does
+- use -g1 for debuginfo generation as this is what upstream 
+  does as well and it saves ~ 2GB of writes
+- use %limit on x86_64 to scale down to less capable workers
+- disable install stripping so that debuginfo is useful
+- use autopatch
+- cleanup constraints to specify only jobs, physicalmemory
+  and memoryperjob to be more flexible on which host to build
+  on
+
 -------------------------------------------------------------------
 Fri Jan 28 15:26:45 UTC 2022 - Wolfgang Rosenauer <wr@rosenauer.org>
 
diff --git a/MozillaFirefox.spec b/MozillaFirefox.spec
index a872aa5..37b94e9 100644
--- a/MozillaFirefox.spec
+++ b/MozillaFirefox.spec
@@ -42,13 +42,10 @@
 # upstream default is clang (to use gcc for large parts set to 0)
 %define clang_build    0
 
-# PIE, full relro
-%define build_hardened 1
-
 %bcond_with only_print_mozconfig
 
 # define if ccache should be used or not
-%define useccache     1
+%define useccache     0
 
 # SLE-12 doesn't have this macro
 %{!?_rpmmacrodir: %global _rpmmacrodir %{_rpmconfigdir}/macros.d}
@@ -326,32 +323,7 @@ fi
 %setup -q -n %{srcname}-%{orig_version}
 %endif
 cd $RPM_BUILD_DIR/%{srcname}-%{orig_version}
-%patch1 -p1
-%patch2 -p1
-%patch3 -p1
-%patch4 -p1
-%patch5 -p1
-%patch6 -p1
-%patch7 -p1
-%patch8 -p1
-%patch9 -p1
-%patch10 -p1
-%patch11 -p1
-%patch12 -p1
-%patch13 -p1
-%patch14 -p1
-%patch15 -p1
-%patch16 -p1
-%patch17 -p1
-%patch18 -p1
-%patch19 -p1
-%patch20 -p1
-%patch21 -p1
-%patch22 -p1
-%patch23 -p1
-# Firefox
-%patch101 -p1
-%patch102 -p1
+%autopatch -p1
 %endif
 
 %build
@@ -410,9 +382,7 @@ export CFLAGS="$CFLAGS -fimplicit-constexpr"
 # Limit RAM usage during link
 export LDFLAGS="${LDFLAGS} -Wl,--no-keep-memory -Wl,--reduce-memory-overheads"
 %endif
-%if 0%{?build_hardened}
 export LDFLAGS="${LDFLAGS} -fPIC -Wl,-z,relro,-z,now"
-%endif
 %ifarch ppc64 ppc64le
 %if 0%{?clang_build} == 0
 export CFLAGS="$CFLAGS -mminimal-toc"
@@ -438,8 +408,8 @@ echo "export MOZ_TELEMETRY_REPORTING=1"
 echo ""
 cat << EOF
 %else
-%ifarch aarch64 %arm ppc64 ppc64le
-%limit_build -m 2000
+%ifarch aarch64 ppc64 ppc64le x86_64
+%limit_build -m 2048
 %endif
 cat << EOF > $MOZCONFIG
 %endif
@@ -462,7 +432,8 @@ ac_add_options --enable-default-toolkit=cairo-gtk3
 %ifarch %ix86 %arm
 ac_add_options --disable-debug-symbols
 %else
-ac_add_options --enable-debug-symbols
+ac_add_options --enable-debug-symbols=-g1
+ac_add_options --disable-install-strip
 %endif
 # building with elf-hack started to fail everywhere with FF73
 #%if 0%{?suse_version} > 1549
@@ -485,7 +456,6 @@ ac_add_options --disable-updater
 ac_add_options --disable-tests
 ac_add_options --enable-alsa
 ac_add_options --disable-debug
-#ac_add_options --enable-chrome-format=jar
 ac_add_options --enable-update-channel=%{update_channel}
 ac_add_options --with-mozilla-api-keyfile=%{SOURCE18}
 # Google-service currently not available for free anymore
@@ -495,6 +465,9 @@ ac_add_options --with-unsigned-addon-scopes=app
 ac_add_options --allow-addon-sideload
 # at least temporary until the "wasi-sysroot" issue is solved
 ac_add_options --without-wasm-sandboxed-libraries
+%ifarch x86_64 aarch64
+ac_add_options --enable-rust-simd
+%endif
 %if %branding
 ac_add_options --enable-official-branding
 %endif
diff --git a/_constraints b/_constraints
index ee68889..f6f9e27 100644
--- a/_constraints
+++ b/_constraints
@@ -1,15 +1,16 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <constraints>
   <hardware>
+    <jobs>4</jobs>
     <disk>
-      <size unit="G">36</size>
+      <size unit="G">24</size>
     </disk>
-    <memory>
+    <physicalmemory>
       <size unit="G">8</size>
-    </memory>
-    <memoryperjob>
-      <size unit="M">2000</size>
-    </memoryperjob>
+    </physicalmemory>
+      <memoryperjob>
+        <size unit="M">1536</size>
+      </memoryperjob>
   </hardware>
   <overwrite>
     <conditions>
@@ -17,9 +18,6 @@
       <arch>armv7l</arch>
     </conditions>
     <hardware>
-      <memoryperjob>
-        <size unit="M">1000</size>
-      </memoryperjob>
       <disk>
         <size unit="G">12</size>
       </disk>
@@ -28,48 +26,4 @@
       </physicalmemory>
     </hardware>
   </overwrite>
-  <overwrite>
-    <conditions>
-      <arch>aarch64</arch>
-    </conditions>
-    <hardware>
-      <processors>4</processors>
-      <disk>
-        <size unit="G">36</size>
-      </disk>
-      <memoryperjob>
-        <size unit="M">1000</size>
-      </memoryperjob>
-      <physicalmemory>
-        <size unit="G">12</size>
-      </physicalmemory>
-    </hardware>
-  </overwrite>
-  <overwrite>
-    <conditions>
-      <arch>x86_64</arch>
-    </conditions>
-    <hardware>
-      <memory>
-        <size unit="G">18</size>
-      </memory>
-    </hardware>
-  </overwrite>
-  <overwrite>
-    <conditions>
-      <arch>ppc64</arch>
-      <arch>ppc64le</arch>
-    </conditions>
-    <hardware>
-      <disk>
-        <size unit="G">36</size>
-      </disk>
-      <physicalmemory>
-        <size unit="G">11</size>
-      </physicalmemory>
-      <memoryperjob>
-        <size unit="M">2500</size>
-      </memoryperjob>
-    </hardware>
-  </overwrite>
 </constraints>