# Add nodes or add CPU

**URL:** <https://discuss.elastic.co/t/add-nodes-or-add-cpu/281744>\
**Category:** Elasticsearch\
**Created:** [August 17, 2021, 7:55pm UTC](https://discuss.elastic.co/t/add-nodes-or-add-cpu/281744 "2021-08-17T19:55:57Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![terrainc](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/terrainc/32/81564_2.png) [@terrainc](https://discuss.elastic.co/u/terrainc)\
**Post date:** [August 17, 2021, 7:55pm UTC](https://discuss.elastic.co/t/add-nodes-or-add-cpu/281744/1 "2021-08-17T19:55:57Z")

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Hi! I have 3 nodes cluster (build on virtual machines 24 cores 72Gb mem each). 120k/s messages.  
Cpu usage about 75-80% so, probably, I need to add more CPU. Also I want to add more disk space (x2 more).  
So I have two ways. First, I can to add CPU and disk to current nodes. Second way is to add 3 more nodes.  
So question is which way is better?

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**Author:** ![stephenb](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/stephenb/32/40856_2.png) [@stephenb](https://discuss.elastic.co/u/stephenb)\
**Post date:** [August 17, 2021, 9:08pm UTC](https://discuss.elastic.co/t/add-nodes-or-add-cpu/281744/2 "2021-08-17T21:08:46Z")

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Hi @terrainc Welcome to the Community

As you allude to there is probably no "absolute correct" answer but I will provide my opinion, others may provide different, and of course there is always tons of details which we have not covered, (use case, total storage, write / read throughput goals etc)

In my opinion you should start to scale horizontally ... Why?

- You already have pretty scaled / beefy vertically scaled nodes,

- Max JVM Heap is 28 - 30GB so per node, more nodes will allow more heap, more shards etc.

- If you want more parallelism for write (and perhaps read) distributing more primary shards across more nodes can help

- Also IF you happen to lose a node, it will be less impactful to the overall system, at some point with a distributed system I will take more smaller over less larger...

Cons : More to Manage and Upgrade.

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**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [September 14, 2021, 9:09pm UTC](https://discuss.elastic.co/t/add-nodes-or-add-cpu/281744/3 "2021-09-14T21:09:10Z")

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