What is a good transfer speed for a USB2.0 Flash Drive?

Question

Transfer speed of flash drives seems to vary significantly. What do people see as the minimum acceptable performance (read / write in MB/sec)? What would constitute really good performance?

Answer 1

Jeff Atwood wrote a nice post on Coding Horror about large USB flash drive performances. I recommend you read the full article. Below is an excerpt:

Modern 2.5" hard drive performance looks something like this:

HDD Sequential Read 55 MB/sec HDD Sequential Write 55 MB/sec

But what about large USB flash drives? How do they compare to typical hard drive speeds, much less the awe-inspiring Velociraptor? X-Bit Labs recently reviewed three 32 GB USB flash drives:

Type - Sequential Read - Sequential Write
32 GB Corsair Flash Voyager - 22 MB/sec - 10 MB/sec
32 GB OCZ Rally 2 - 30 MB/sec - 22 MB/sec
32 GB Patriot Xporter XT - 31 MB/sec - 17 MB/sec

Answer 2

This doesn't answer the question of what people see as minimum acceptable performance, but there are some good charts at tom's hardware.