New post

content/blog/disabling-cpus-save-power.md

@@ -0,0 +1,45 @@
+---
+title: "Disabling CPUs to Save Power"
+date: 2024-04-06T20:48:52-04:00
+draft: false
+tags: []
+math: false
+medium_enabled: false
+---
+
+Looking for ways to reduce the power usage of my home server? This post shows a not-so-scientific look at how disabling CPUs can help save some power.
+
+I run a Dell PowerEdge R430 with an Intel Xeon E5-2643 v3 CPU. This gives me 12 physical cores, and with hyperthreading this presents itself as 24 logical cores.
+
+Given that I mostly use my server as media storage, most of those CPUs sit idle most of the time. My thought is, how much power can I save if I disable some of these unused cores?
+
+For idle workloads disabling the CPU does not result in any noticeable power savings. The power savings is significant, however, if you analyze the system under load.
+
+To conduct this experiment, I used a [Kill a Watt](https://en.wikipedia.org/wiki/Kill_A_Watt) measuring device which monitors the power usage of whatever is plugged into it.
+
+To disable a CPU in Linux, use the following command:
+
+```bash
+# Disable CPU 23
+echo 0 | sudo tee /sys/devices/system/cpu/cpu23/online > /dev/null
+```
+
+Repeat for any CPUs you want to disable. You can see which CPUs are available using `ls /sys/devices/system/cpu`. The `htop` tool will display in addition to the CPU utilization, which CPUs are offline.
+
+To get the system under load, I used the `stress` tool.
+
+```bash
+# Spin off 24 dummy tasks that max out each CPU
+stress -c 24
+```
+
+I ran the stress tool with the corresponding number of logical CPUs I had online to come up with the following table:
+
+| # Online Logical CPU | Power (Watts) |
+| -------------------- | ------------- |
+| 24                   | 360           |
+| 12                   | 295           |
+| 6                    | 194           |
+| 4                    | 173           |
+
+Cutting down to 4 logical CPUs can cut the power usage under load in half! Do note though, that this exchanges performance for power savings. If you are running a low amount of services on your home server or can wait a bit of extra time for a computation to finish, consider disabling some of your CPUs.

content/menu/_index.md

@@ -30,6 +30,7 @@ The following menu contains meals that are in rotation at my home. These are mad
 
 ## Soups
 
+- [Beef Taco](beef-taco-soup/)
 - [Pork Pozole](pork-pozole/)
 - Chicken & Gnocchi
 - {{< vegetarian >}}Broccoli Cheddar

content/menu/beef-taco-soup.md

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+---
+title: "Beef Taco Soup"
+date: 2024-04-06
+hideDate: true
+draft: false
+---
+
+## Ingredients
+
+- Beef
+- 1/2 yellow onion
+- 1/2 green bell pepper
+- 1/2 red bell pepper
+- 24 oz beef broth
+- 1 can diced tomatoes
+- 2 ounces cream cheese
+- 1/2 cup of heavy whipping cream
+- 1 cup cheddar cheese
+- 1 tablespoon chili powder
+- 1 tablespoon cumin
+- 2 teaspoons onion powder
+- 3 teaspoons oregano
+- 1 teaspoon garlic powder
+- 1 teapoon paprika
+- 1/2 teaspoon cayenne pepper
+
+## Recipe
+1. Cook beef
+2. Blend diced tomatoes and beef broth together.
+3. Put tomato and broth blend in pot and bring to a boil,
+then reduce heat to a simmer.
+4. Meanwhile start cooking the onion and bell peppers.
+5. Add beef, onion, bell peppers, and spices to the pot.
+6. Cook for 30 minutes
+7. Add cream cheese, heavy whipping cream, and cheddar cheese
+to the pot.
+8. Wait until everything is all melted and smooth then serve.