Question

Wondering why a particular binary write operation in VB is so slow. The function reads a Byte array from memory and dumps it into a file like this:

Open Destination For Binary Access Write As #1

Dim startP, endP As Long
startP = BinaryStart
endP = UBound(ReadBuf) - 1
Dim i as Integer

For i = startP To endP

    DoEvents
    Put #1, (i - BinaryStart) + 1, ReadBuf(i)

Next

Close #1

For two megabytes on a slower system, this can take up to a minute. Can anyone tell me why this is so slow?

Edit: The reason for choosing VB6 is that it runs on 100% of our target platforms as a single EXE, without any separate dependencies (except VBRUN, which is on pretty much everything).

Answer 1

Well, are you reading and writing each byte 1 by one? In that case you are iterating through 2 million elements instead of just taking a chunk of data at a time and write it to the stream.