<p>Without knowing your <code>bitcoin.conf</code> settings and <code>debug.log</code>, it is difficult to say. Generally speaking, however, here are a few things:</p>
<ul>
<li>365GB is not enough space, so you'll have to run in pruned mode or upgrade your hard drive</li>
<li>SSD drives tend to be much faster than HDD drives when performing IBD</li>
<li><code>dbcache</code> is 450MiB by default. If you have 16GB of RAM available, you can set <code>dbcache</code> to a much higher value to help speed up IBD</li>
<li>If you are pruning, make sure to set your <code>dbcache</code> and <code>prune</code> values to be similar. If your <code>prune</code> value is lower than your <code>dbcache</code> value, your node will not use all the available memory. See <a href="https://bitcoin.stackexchange.com/questions/116653/does-pruning-during-ibd-reduce-the-ability-to-utilize-the-dbcache-fully">Does pruning during IBD reduce the ability to utilize the dbcache fully?</a> for more information</li>
</ul>
<p>EDIT: As pointed out in the comments, headers sync should not be taking 3 hours. Based on <a href="https://github.com/bitcoin/bitcoin/issues/26391" rel="nofollow noreferrer">https://github.com/bitcoin/bitcoin/issues/26391</a> , it sounds like corrupted block data could be the cause. If you can confirm that by looking in your <code>debug.log</code>, restarting your node with <code>-reindex</code> is an option. However, it's difficult to recommend a solution without knowing what's in your <code>debug.log</code> first.</p>

CC BY-SA 4.0
2023-02-14T12:00:39.900Z
That's good general advice, but i don't think using a SSD or increasing the dbcache applies here: it's apparently stuck at syncing headers.
Antoine Poinsot
CC BY-SA 4.0
2023-02-14T12:55:25.090Z
Ah, I missed the "3 hours" comment in the OP. Do you know how long headers sync should take normally?
josie
CC BY-SA 4.0
2023-02-14T13:00:03.393Z
A handful of minutes. :/ (Well, depend on the bandwidth but they disclaimed having a decent connection.)
Antoine Poinsot
CC BY-SA 4.0
2023-02-14T08:48:48.527Z
2023-02-14T13:19:52.680Z
2023-02-14T13:19:52.680Z
josie
<p>Why not collecting and insepcting debug logs? There could be traces of the reasons that the node is synchornising slowly. Upload a debug.log file generated by Bitcoin Core started with the -debug option, i.e.</p>
<blockquote>
<p>.\bitcoin-qt.exe -debug</p>
</blockquote>
<p>3 hours of headers synchronisation doesn't seem to be slow to me.</p>

CC BY-SA 4.0
2023-02-14T13:57:45.330Z
The headers are less than 65 MB. Header Sync should take no more than a few minutes.
Murch
CC BY-SA 4.0
2023-02-14T07:03:12.963Z
2023-02-14T07:03:12.963Z
Greg Tonoski
<p>I¹ am trying to sync Bitcoin Core v24.0.1 on my Desktop with 16 GB RAM and an Intel Core i7-7700HQ processor, but it is taking forever even to get past the header synchronization. It tells me that it will take over 3.5 years to synchronize.</p>
<p><a href="https://i.sstatic.net/wjKmQ.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/wjKmQ.png" alt="enter image description here" /></a></p>
<p>3 hours later, my node is still in Header Synchronization:<br />
<a href="https://i.sstatic.net/ZB8Zx.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/ZB8Zx.png" alt="enter image description here" /></a></p>
<ul>
<li>I have a decent internet connection and am connected to my router via wifi</li>
<li>I downloaded Bitcoin Core v24.0.1 from bitcoincore.org</li>
<li>I’m using an internal hard drive</li>
<li>I have ten connections, but have only received about 340 kB across my eight outbound connections in the past ~10 minutes minutes <a href="https://i.sstatic.net/YDRce.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/YDRce.png" alt="enter image description here" /></a></li>
<li>I have tried to add a few nodes from bitnodes.io via <code>addnode &lt;ip&gt; onetry</code> to perhaps learn about more peers (and the added nodes show up when I call <code>getaddednodeinfo</code> as past connections)</li>
<li>I have over 365 GB of free disk space</li>
</ul>
<h2>Update:</h2>
<ul>
<li>My node was already configured to run in pruning mode</li>
<li>I’ve increased my dbcache to 10 GB</li>
<li>My debug.log appears to show that I’m switching my peers frequently <a href="https://i.sstatic.net/cgcb9.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/cgcb9.png" alt="enter image description here" /></a></li>
</ul>
<p>Any ideas what else I should try?</p>
<hr />
<p>¹Asking for a friend.</p>

CC BY-SA 4.0
2023-02-15T09:00:47.793Z
What has changed in the next few hours? Has the header synchronization finished? Has anything progressed?
Greg Tonoski
<bitcoin-core><synchronization><windows>
What could be the reason that my node syncs so slowly during Header Synchronization?
Murch
# What could be the reason that my node syncs so slowly during Header Synchronization?

(Asked by: username_0 on 2023-02-14)

I¹ am trying to sync Bitcoin Core v24.0.1 on my Desktop with 16 GB RAM and an Intel Core i7-7700HQ processor, but it is taking forever even to get past the header synchronization. It tells me that it will take over 3.5 years to synchronize.

[![enter image description here](https://i.sstatic.net/wjKmQ.png)](https://i.sstatic.net/wjKmQ.png)

3 hours later, my node is still in Header Synchronization:  
[![enter image description here](https://i.sstatic.net/ZB8Zx.png)](https://i.sstatic.net/ZB8Zx.png)

* I have a decent internet connection and am connected to my router via wifi
* I downloaded Bitcoin Core v24.0.1 from bitcoincore.org
* I’m using an internal hard drive
* I have ten connections, but have only received about 340 kB across my eight outbound connections in the past ~10 minutes minutes [![enter image description here](https://i.sstatic.net/YDRce.png)](https://i.sstatic.net/YDRce.png)
* I have tried to add a few nodes from bitnodes.io via `addnode <ip> onetry` to perhaps learn about more peers (and the added nodes show up when I call `getaddednodeinfo` as past connections)
* I have over 365 GB of free disk space

## Update:

* My node was already configured to run in pruning mode
* I’ve increased my dbcache to 10 GB
* My debug.log appears to show that I’m switching my peers frequently [![enter image description here](https://i.sstatic.net/cgcb9.png)](https://i.sstatic.net/cgcb9.png)

Any ideas what else I should try?

---

¹Asking for a friend.

**Tags:** bitcoin-core, synchronization, windows

> **Comments:**
> **username_1**: What has changed in the next few hours? Has the header synchronization finished? Has anything progressed?  

---

## 2 answers

### Answer by username_2 on 2023-02-14. Score: 2

Without knowing your `bitcoin.conf` settings and `debug.log`, it is difficult to say. Generally speaking, however, here are a few things:

* 365GB is not enough space, so you'll have to run in pruned mode or upgrade your hard drive
* SSD drives tend to be much faster than HDD drives when performing IBD
* `dbcache` is 450MiB by default. If you have 16GB of RAM available, you can set `dbcache` to a much higher value to help speed up IBD
* If you are pruning, make sure to set your `dbcache` and `prune` values to be similar. If your `prune` value is lower than your `dbcache` value, your node will not use all the available memory. See [Does pruning during IBD reduce the ability to utilize the dbcache fully?](https://bitcoin.stackexchange.com/questions/116653/does-pruning-during-ibd-reduce-the-ability-to-utilize-the-dbcache-fully) for more information

EDIT: As pointed out in the comments, headers sync should not be taking 3 hours. Based on <https://github.com/bitcoin/bitcoin/issues/26391> , it sounds like corrupted block data could be the cause. If you can confirm that by looking in your `debug.log`, restarting your node with `-reindex` is an option. However, it's difficult to recommend a solution without knowing what's in your `debug.log` first.

> **Comments:**
> **username_3**: That's good general advice, but i don't think using a SSD or increasing the dbcache applies here: it's apparently stuck at syncing headers.  
> **username_2**: Ah, I missed the "3 hours" comment in the OP. Do you know how long headers sync should take normally?  
> **username_3**: A handful of minutes. :/ (Well, depend on the bandwidth but they disclaimed having a decent connection.)  

---

### Answer by username_1 on 2023-02-14. Score: 0

Why not collecting and insepcting debug logs? There could be traces of the reasons that the node is synchornising slowly. Upload a debug.log file generated by Bitcoin Core started with the -debug option, i.e.

> .\bitcoin-qt.exe -debug

3 hours of headers synchronisation doesn't seem to be slow to me.

> **Comments:**
> **username_0**: The headers are less than 65 MB. Header Sync should take no more than a few minutes.  

---

