Slow performance of an encrypted VeraCrypt container running on a USB flash drive

Question

I have encrypted a container and stored it on my Mac using VeraCrypt, it’s about 62GB. I then moved the encrypted file and put it on a USB flash drive. But when I mount it from the USB flash drive and open VMware I have some what slow performance from my virtual machine.

Can this be because I am uploading something that is taking a good amount of time? Or is it my USB flash drive which is a 64GB USB?

the mac am using is a Imac (27" retina display, late 2014) and the OS is 10.11 El Capitan

the flash drive is a Kingston data traveler G4 64 gb with standard speed as the website says, it doesn't go specific.

Mac specs: graphis: AMD Radeon R9 M295X 4096 MB memory: 32 GB 1600 MHz DDR3 processor: 4 GHz Intel Core i7

Answer 1

You are correct in your suspicion of your USB stick. USB flash drives typically do not have very good performance (read/write) compared to plain old internal hard drives or solid state drives. VM's which will do lots of reading and writing, will tax your USB stick greatly.

Consider an external hard drive or SSD, preferably with an external power source (a power cable in addition to the USB cable). If you want to stick with a USB stick, you can look around, and might be able to find "better" USB drives. Keep an eye out on read/write speeds. If it does not specify, don't be surprised if it's slow.

As an example, look at these two drives (this and that) listed on Newegg from the same manufacturer (Kingston), at the same capacity (64GB), and both using USB 3. The first one has speeds of:

Read: up to 100 MB/s
Write: up to 15 MB/s

The second one has speeds of:

Read: up to 250MB/s
Write: up to 85MB/s

--- EDIT ---

Given the model of your USB flash drive, I am certain that is the limiting factor. You will need something more powerful.