<blockquote>
<p><strong>Can multiple candidate blocks be mined concurrently by the miner, even if at the end only one block gets added to the chain every 10 mins?</strong></p>
</blockquote>
<p>Yes.</p>
<p>And the 10 minute thing is an <strong>average</strong>. The interval between two successive blocks might easily be 3 seconds or 3 hours.</p>

CC BY-SA 4.0
2024-05-04T09:02:40.393Z
2024-05-07T09:25:55.203Z
2024-05-07T09:25:55.203Z
RedGrittyBrick
<blockquote>
<p>...can the multiple candidate blocks be processed by the miner
concurrently so it keeps fetching from the tx_pool?</p>
</blockquote>
<p>Yes anyone is free to construct and perform work on blocks with transactions as they see fit.</p>
<blockquote>
<p>...does this mean the ledger of each individual node gets updated 10
mins?</p>
</blockquote>
<p>Yes, well the <a href="https://bitcoin.stackexchange.com/a/122811/34190">UTXO set</a>, <a href="https://bitcoin.stackexchange.com/a/67625/34190">approximately</a> every 10 minutes.</p>
<blockquote>
<p>When do i get my reward? When A's chain accepts my block as the most
recent one?</p>
</blockquote>
<p>The reward can only be spent after the block <a href="https://learnmeabitcoin.com/technical/mining/coinbase-transaction/#coinbase-maturity" rel="nofollow noreferrer">reaches a depth of &gt;100</a>.</p>

CC BY-SA 4.0
2024-05-04T10:58:34.027Z
Well if multiple blocks are being mined but only one gets selected; the work put in the others would be wasted. So what is the incentive to do that?
Geek
CC BY-SA 4.0
2024-05-04T11:09:06.973Z
@Geek same as the incentive to enter a lottery... the chance of winning
Lee
CC BY-SA 4.0
2024-05-04T11:20:02.247Z
ok got it. Can u explain a bit more about the 10 min being **avg** ; because since target for any node is adjusted every 2016 blocks this means that before the next adjustment there could be many blocks which got added much sooner than 10 mins. Can this be a security concern because if another malicious actor has a higher hash rate they could just overwhelm me with their blocks ? 

And is the target adjusted by observing the timestamp of the received blocks after every 2016th block?
Geek
CC BY-SA 4.0
2024-05-04T09:03:57.477Z
2024-05-04T09:11:00.620Z
2024-05-04T09:11:00.620Z
Lee
<p>Miners continuously work on finding new blocks and update block templates whenever they see fit. A new block is found when a block header surpasses the current difficulty requirement. The successful miner publishes the block as soon as they find it, other nodes validate and relay the block, and miners update their block templates to build on top of the new best chaintip.</p>
<p>Because <a href="https://bitcoin.stackexchange.com/q/36192/5406">every single attempt</a> at finding a new block has a minuscule chance of succeeding, blocks come in randomly. Sometimes multiple blocks are found within one minute, sometimes it takes over an hour for a new block to be found, but miners are always working on finding the next block and the expected time until the next block is always ten minutes away.</p>

CC BY-SA 4.0
2024-05-06T13:35:05.360Z
2024-05-06T13:35:05.360Z
Murch
<p>I read that every 10 minutes, the miner would fetch txs from the tx_mempool, process them, create a candidate block, do the proof of work and then broadcast it to the network.
Does this mean that the next batch of txs will be fetched once after 10 mins?
Or can multiple candidate blocks be processed by the miner concurrently so it keeps fetching from the tx_pool?</p>
<p>Even if we do mine multiple blocks within the 10 min window, if only one is going to get selected by the network then a lot of computation has been wasted for nothing.</p>
<hr />
<p>The two other questions were split off to:</p>
<ul>
<li><a href="https://bitcoin.stackexchange.com/q/122885/13866">If multiple nodes start at different points, so do we need to sync the nodes so that they are operating at the same time</a></li>
<li><a href="https://bitcoin.stackexchange.com/q/122887/13866">When exactly does the miner get their reward?</a></li>
</ul>

<mining-theory><synchronization><mining-reward><coinbase-transaction><block-interval>
Can multiple candidate blocks be mined concurrently by the miner, even if at the end only one block gets added to the chain every 10 mins?
Geek
# Can multiple candidate blocks be mined concurrently by the miner, even if at the end only one block gets added to the chain every 10 mins?

(Asked by: username_0 on 2024-05-03)

I read that every 10 minutes, the miner would fetch txs from the tx\_mempool, process them, create a candidate block, do the proof of work and then broadcast it to the network.
Does this mean that the next batch of txs will be fetched once after 10 mins?
Or can multiple candidate blocks be processed by the miner concurrently so it keeps fetching from the tx\_pool?

Even if we do mine multiple blocks within the 10 min window, if only one is going to get selected by the network then a lot of computation has been wasted for nothing.

---

The two other questions were split off to:

* [If multiple nodes start at different points, so do we need to sync the nodes so that they are operating at the same time](https://bitcoin.stackexchange.com/q/122885/13866)
* [When exactly does the miner get their reward?](https://bitcoin.stackexchange.com/q/122887/13866)

**Tags:** mining-theory, synchronization, mining-reward, coinbase-transaction, block-interval


---

## 3 answers

### Answer by username_1 on 2024-05-04. Score: 0

> **Can multiple candidate blocks be mined concurrently by the miner, even if at the end only one block gets added to the chain every 10 mins?**

Yes.

And the 10 minute thing is an **average**. The interval between two successive blocks might easily be 3 seconds or 3 hours.


---

### Answer by username_2 on 2024-05-04. Score: 0

> ...can the multiple candidate blocks be processed by the miner
> concurrently so it keeps fetching from the tx\_pool?

Yes anyone is free to construct and perform work on blocks with transactions as they see fit.

> ...does this mean the ledger of each individual node gets updated 10
> mins?

Yes, well the [UTXO set](https://bitcoin.stackexchange.com/a/122811/34190), [approximately](https://bitcoin.stackexchange.com/a/67625/34190) every 10 minutes.

> When do i get my reward? When A's chain accepts my block as the most
> recent one?

The reward can only be spent after the block [reaches a depth of >100](https://learnmeabitcoin.com/technical/mining/coinbase-transaction/#coinbase-maturity).

> **Comments:**
> **username_0**: Well if multiple blocks are being mined but only one gets selected; the work put in the others would be wasted. So what is the incentive to do that?  
> **username_2**: @username_0 same as the incentive to enter a lottery... the chance of winning  
> **username_0**: ok got it. Can u explain a bit more about the 10 min being **avg** ; because since target for any node is adjusted every 2016 blocks this means that before the next adjustment there could be many blocks which got added much sooner than 10 mins. Can this be a security concern because if another malicious actor has a higher hash rate they could just overwhelm me with their blocks ?   And is the target adjusted by observing the timestamp of the received blocks after every 2016th block?  

---

### Answer by username_3 on 2024-05-06. Score: 0

Miners continuously work on finding new blocks and update block templates whenever they see fit. A new block is found when a block header surpasses the current difficulty requirement. The successful miner publishes the block as soon as they find it, other nodes validate and relay the block, and miners update their block templates to build on top of the new best chaintip.

Because [every single attempt](https://bitcoin.stackexchange.com/q/36192/5406) at finding a new block has a minuscule chance of succeeding, blocks come in randomly. Sometimes multiple blocks are found within one minute, sometimes it takes over an hour for a new block to be found, but miners are always working on finding the next block and the expected time until the next block is always ten minutes away.


---

