I have Bitcoin-QT 0.9.3 (zip version). bitcoin-qt.exe sits on the internal HDD of my laptop. All of the other stuff (blockchain, wallet,...) on a 128GB USB drive, fully encrypted with TrueCrypt (AES encryption), connected via USB2.0 port. I have bootstrap.dat (21GB copy of blockchain) on the USB drive, too.


everything is slow via USB2.0 flashdrive. Import of bootstrap.dat file is barely making progress. It's been 7 days and I'm getting older. The progress bar shows it's 1/3 ready. No other application reads/writes to the USB drive.


I'm considering swapping my flash drive for an external hard drive, but keeping TrueCrypt. Would this help, or would the fact that I have no USB3.0 ports be more important? I'm looking for satisfactory speed results that other people are getting by using bootstrap.dat. As slow as it's going, I'll import the blockchain slower than it's generated.

I would prefer your experience over suggestions like "try this..." becase I don't have free HDD space to "experiment", I just want to buy some HDD and hook it up to USB, but I'm worried that USB2.0 port itself is a bottleneck and I would just waste money. Thus I'm here for clues.

I'd prefer an HDD instead of an SSD, but I will hear out both options. I'm not interested in thin clients. (basically I'm looking for cheapest external memory that would work, because flash drives don't work with Bitcoin-QT).

  • TrueCrypt shoukd be able to encrypt/decrypt about 1GB/s, so I consider it unlikely that it's the speed limiter. Jan 22, 2015 at 17:13
  • you are right about the TrueCrypt not being the problem: I was able to test import speed of bootstrap.dat file on BOTH TrueCrypt encrypted and non-encrypted USB2.0 flash drive and the result is the same, - they are both very slow (with no visible difference). It looks like the flash drives are just a bad choice for storage device to run Bitcoin on. I assume the 3.0 USB flash drive would make no visible difference, because the problem seems to be with the flash drive itself.
    – ctrl
    Feb 28, 2015 at 15:38

2 Answers 2


The cheapest external memory that would work fast enough to be acceptable is SATA3 HDD via usb2.0 adapter. (I didn't tested SATA1 or 2 nor old IDE drives, if you have them with over 500GB capacity you can probably use them too. I couldn't find them for my test). For comparison, here's the time was needed to import 21GB blockchain:

  • 2.0 USB flashdrive: never finished. took 7 days non-stop for progress bar to reach 1/3. and then speed slowed down to the point that there was no noticeable progress.
  • SATA3 HDD via USB2.0 adapter: about 20 hours non-stop.

I'm using a USB 3.0 512 GB thumbdrive with a copy of the block chain, current as of 3 hours ago; bitcoin-qt ran, got about 50% synched, and hasn't moved in the last 12 hours. files still being updated / written to thumb drive, but does not appear to be making progress..

so USB 3 wouldn't appear to help you.

Could the threading of version 0.11.1 could be negatively impacted by the thumb drive? specs on the drive are read/write > 300 mb/sec.

I've had similar challenges running VMware virtual machines off thumb drives; running them from a USB 3 passport drive with the VM works fine, so i'll try that for the blockchain storage & see if that works.

  • This answer is weird. While it seems to address the question of the asker in some degree, it also seems to be asking new questions and speculating. In answers please focus on responding to the asker's question. If you have a new question, please create another topic.
    – Murch
    Jun 15, 2016 at 8:11

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