Why is my Bitcoin node indexing so slow?

I’m struggling to get my Bitcoin node up and running. I’m on Bitcoin Core Ver 26.0. It started off indexing pretty quickly, but now it’s crawling. It even shut down twice on its own. Could that mess up the indexing? I restarted it, but it’s still barely moving. Only 361,355 blocks left, but it says it’s gonna take 10 days to finish. Been running for 30 hours.

What you’re seeing is pretty typical. Just a heads up, you're not downloading a node; your computer is acting as the node. You’re actually pulling in all of Bitcoin’s blockchain data, which is over 500GB. Running a prune node helps if you’re excluding some data from a certain timeframe. Depending on your computer’s power and internet speed, syncing can take a couple of days.

Thanks for the info! I'm on a PC with 8GB of RAM and an i7 processor, plus a 400 Mbps internet. I'm using a 2TB Samsung T7 external drive for the full node. It just felt like it was going faster before suddenly slowing down. If it’s still downloading, does that mean there’s no corruption in what’s been downloaded so far? And when you say resync, do I need to wipe everything?

You might wanna increase the dbcache setting. Make it about half of your RAM in MB, and put that in your bitcoin.conf file. Also, try using blocksonly=1 when you're downloading the blockchain. This way, your node will just deal with block data and ignore unconfirmed transactions during the initial download.

Yeah, increasing the database cache could boost your sync speed, especially with that external drive you’re using.

First, check if your hard disk is maxed out at 100%. That’ll definitely slow things. I’ve had issues with my download due to low bandwidth here, but I found a trick: get an external SSD, copy your Bitcoin data there, and rename the old one just in case things go wrong. And remember to save your config file as.conf, not.txt.

Two things to consider: get more RAM and ditch the external drive. They can easily get disconnected, which leads to corruption. The chainstate is about 11GB, so that won't fit in your RAM, and you’ll end up writing tons of data to your disk. More RAM will seriously improve your overall experience.

What if I just use a non-SSD drive? I got the SSD because my disk was always at 100% while syncing. Does more RAM help keep disk usage down?

A "non-SSD drive"? You mean a traditional HDD? What’s the interface of your external drive? Most probably USB3 or something. If you’re not using UASP, it can really slow down the SSD. Internal drives are preferred for SSDs. More RAM means you can keep more data readily available, which is way faster than accessing data from disk.

If you don’t have enough RAM, it’s gonna be rough. If that 11GB from chainstate can’t fit in your cache, you’re gonna be grinding on that HDD. Just curious, if you're still on an old HDD, why not switch to an internal SSD? I did that long ago and it was a big deal! Just make sure you get a good one for sustained writes.

That explains why my OS crashed without warning. Almost lost important files. Does Windows just suck? lol

Not really, the OS should terminate the app when it runs out of memory instead of crashing.

I had a crash too, but I managed to recover some files using cmd prompt. It was my first experience with that while running Bitcoin Core. What could’ve caused it?

That’s super slow! Last time I did a reindex, it took me about 1-2 days on HDD. If you’re not using your PC for other things, close other apps so Bitcoin Core can use more RAM. You might want to start a new thread about your issue instead of continuing here.