diff --git a/concho/config.py b/concho/config.py
index 21f5b0c..aaebc98 100644
--- a/concho/config.py
+++ b/concho/config.py
@@ -375,7 +375,19 @@ class Config():
 
     def get_flops(self):
         # print('%d servers * %d cpu %s * %d cores @ %f (%d flops/cycle)' % (self.num_servers, self.num_cpu_per_server, str(self.cpu.uid), self.cpu.num_cores, self.cpu.clock, self.cpu.num_dp_flop_per_cycle))
-        flops = self.cpu.num_dp_flop_per_cycle * self.cpu.clock * 1.e9 * self.cpu.num_cores * self.num_cpu_per_server * self.num_servers
+        dynamic_frequency_scaling = 1.0  # https://en.wikichip.org/wiki/intel/frequency_behavior
+        # https://www.nas.nasa.gov/hecc/support/kb/cascade-lake-processors_579.html
+        # The Intel Cascade Lake processor incorporated into the Aitken cluster is the 20-core Xeon Gold 6248 model. Its base clock speed is 2.5 GHz for non-AVX, 1.9 GHz for AVX2, and 1.6 GHz for AVX-512.
+        simd_id = get_simd_id(self.cpu.architecture)
+        if simd_id == 'avx-512':
+            if self.cpu.architecture in ['skylake', 'cascadelake']:
+                xeon_6248_base_freq = 2500.0  # https://en.wikichip.org/wiki/intel/xeon_gold/6248
+                xeon_6248_avx512_base_freq = 1600.0  # https://en.wikichip.org/wiki/intel/xeon_gold/6248
+                dynamic_frequency_scaling = xeon_6248_avx512_base_freq / xeon_6248_base_freq
+            elif self.cpu.architecture == 'icelake':
+                dynamic_frequency_scaling = 0.9
+        cpu_clock_when_computing = self.cpu.clock * dynamic_frequency_scaling
+        flops = self.cpu.num_dp_flop_per_cycle * cpu_clock_when_computing * 1.e9 * self.cpu.num_cores * self.num_cpu_per_server * self.num_servers
         return flops
 
     def _init_dimm_slots(self):
diff --git a/readme.md b/readme.md
index 7afbcdd..b01a47d 100644
--- a/readme.md
+++ b/readme.md
@@ -6,3 +6,51 @@ usage:
 ```console
 graffy@graffy-ws2:~/work/concho$ PYTHONPATH=. python3 ./tests/test1.py 
 ```
+
+
+# intel dynamic frequency scaling
+
+## xeon silver 4116
+
+[https://en.wikichip.org/wiki/intel/xeon_silver/4116#Frequencies]
+
+Turbo Frequency/Active Cores
+| Mode   | Base      |         1 |         2 |         3 |         4 |         5 |         6 |         7 |         8 |         9 |        10 |        11 |        12 |
+| :----- | :-------- | --------: | --------: | --------: | --------: | --------: | --------: | --------: | --------: | --------: | --------: | --------: | --------: |
+| Normal | 2,100 MHz | 3,000 MHz | 3,000 MHz | 2,800 MHz | 2,800 MHz | 2,700 MHz | 2,700 MHz | 2,700 MHz | 2,700 MHz | 2,400 MHz | 2,400 MHz | 2,400 MHz | 2,400 MHz |
+| AVX2   | 1,700 MHz | 2,900 MHz | 2,900 MHz | 2,700 MHz | 2,700 MHz | 2,400 MHz | 2,400 MHz | 2,400 MHz | 2,400 MHz | 2,100 MHz | 2,100 MHz | 2,100 MHz | 2,100 MHz |
+| AVX512 | 1,100 MHz | 1,800 MHz | 1,800 MHz | 1,600 MHz | 1,600 MHz | 1,500 MHz | 1,500 MHz | 1,500 MHz | 1,500 MHz | 1,400 MHz | 1,400 MHz | 1,400 MHz | 1,400 MHz |
+
+
+## xeon gold 6140
+
+[https://en.wikichip.org/wiki/intel/xeon_gold/6140]
+Turbo Frequency/Active Cores
+
+| Mode   | Base      |         1 |         2 |         3 |         4 |         5 |         6 |         7 |         8 |         9 |        10 |        11 |        12 |        13 |        14 |        15 |        16 |        17 |        18 |
+| :----- | :-------- | --------: | --------: | --------: | --------: | --------: | --------: | --------: | --------: | --------: | --------: | --------: | --------: | --------: | --------: | --------: | --------: | --------: | --------: |
+| Normal | 2,300 MHz | 3,700 MHz | 3,700 MHz | 3,500 MHz | 3,500 MHz | 3,400 MHz | 3,400 MHz | 3,400 MHz | 3,400 MHz | 3,400 MHz | 3,400 MHz | 3,400 MHz | 3,400 MHz | 3,100 MHz | 3,100 MHz | 3,100 MHz | 3,100 MHz | 3,000 MHz | 3,000 MHz |
+| AVX2   | 1,900 MHz | 3,600 MHz | 3,600 MHz | 3,400 MHz | 3,400 MHz | 3,300 MHz | 3,300 MHz | 3,300 MHz | 3,300 MHz | 3,000 MHz | 3,000 MHz | 3,000 MHz | 3,000 MHz | 2,700 MHz | 2,700 MHz | 2,700 MHz | 2,700 MHz | 2,600 MHz | 2,600 MHz |
+| AVX512 | 1,500 MHz | 3,500 MHz | 3,500 MHz | 3,300 MHz | 3,300 MHz | 2,800 MHz | 2,800 MHz | 2,800 MHz | 2,800 MHz | 2,400 MHz | 2,400 MHz | 2,400 MHz | 2,400 MHz | 2,100 MHz | 2,100 MHz | 2,100 MHz | 2,100 MHz | 2,100 MHz | 2,100 MHz |
+
+## xeon gold 6240
+
+[https://en.wikichip.org/wiki/intel/xeon_gold/6240]
+Turbo Frequency/Active Cores
+
+| Mode   | Base     |        1 |        2 |        3 |        4 |        5 |        6 |        7 |        8 |        9 |       10 |       11 |       12 |       13 |       14 |       15 |       16 |       17 |       18 |
+| :----- | :------- | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: |
+| Normal | 2,600 MHz  | 3,900 MHz  | 3,900 MHz  | 3,700 MHz  | 3,700 MHz  | 3,600 MHz  | 3,600 MHz  | 3,600 MHz  | 3,600 MHz  | 3,600 MHz  | 3,600 MHz  | 3,600 MHz  | 3,600 MHz  | 3,400 MHz  | 3,400 MHz  | 3,400 MHz  | 3,400 MHz  | 3,300 MHz  | 3,300 MHz  |
+| AVX2   | 2,000 MHz  | 3,700 MHz  | 3,700 MHz  | 3,500 MHz  | 3,500 MHz  | 3,400 MHz  | 3,400 MHz  | 3,400 MHz  | 3,400 MHz  | 3,200 MHz  | 3,200 MHz  | 3,200 MHz  | 3,200 MHz  | 2,900 MHz  | 2,900 MHz  | 2,900 MHz  | 2,900 MHz  | 2,800 MHz  | 2,800 MHz  |
+| AVX512 | 1,600 MHz  | 3,700 MHz  | 3,700 MHz  | 3,500 MHz  | 3,500 MHz  | 3,400 MHz  | 3,400 MHz  | 3,400 MHz  | 3,400 MHz  | 2,900 MHz  | 2,900 MHz  | 2,900 MHz  | 2,900 MHz  | 2,600 MHz  | 2,600 MHz  | 2,600 MHz  | 2,600 MHz  | 2,500 MHz  | 2,400 MHz  |
+
+## xeon gold 6248
+
+[https://en.wikichip.org/wiki/intel/xeon_gold/6248]
+Turbo Frequency/Active Cores
+
+| Mode   | Base     |        1 |        2 |        3 |        4 |        5 |        6 |        7 |        8 |        9 |       10 |       11 |       12 |       13 |       14 |       15 |       16 |       17 |       18 |       19 |       20 |
+| :----- | :------- | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: | -------: |
+| Normal | 2,500 MHz  | 3,900 MHz  | 3,900 MHz  | 3,700 MHz  | 3,700 MHz  | 3,600 MHz  | 3,600 MHz  | 3,600 MHz  | 3,600 MHz  | 3,600 MHz  | 3,600 MHz  | 3,600 MHz  | 3,600 MHz  | 3,400 MHz  | 3,400 MHz  | 3,400 MHz  | 3,400 MHz  | 3,200 MHz  | 3,200 MHz  | 3,200 MHz  | 3,200 MHz  |
+| AVX2   | 1,900 MHz  | 3,800 MHz  | 3,800 MHz  | 3,600 MHz  | 3,600 MHz  | 3,500 MHz  | 3,500 MHz  | 3,500 MHz  | 3,500 MHz  | 3,400 MHz  | 3,400 MHz  | 3,400 MHz  | 3,400 MHz  | 3,000 MHz  | 3,000 MHz  | 3,000 MHz  | 3,000 MHz  | 2,800 MHz  | 2,800 MHz  | 2,800 MHz  | 2,800 MHz  |
+| AVX512 | 1,600 MHz  | 3,800 MHz  | 3,800 MHz  | 3,600 MHz  | 3,600 MHz  | 3,500 MHz  | 3,500 MHz  | 3,500 MHz  | 3,500 MHz  | 3,000 MHz  | 3,000 MHz  | 3,000 MHz  | 3,000 MHz  | 2,700 MHz  | 2,700 MHz  | 2,700 MHz  | 2,700 MHz  | 2,500 MHz  | 2,500 MHz  | 2,500 MHz  | 2,500 MHz  |
\ No newline at end of file