Committing Byte Array to Disk

[jwgoerlich@gmail.com]

What is the fastest way of writing a Byte array to disk? I have a 512
MB array in memory. I am writing to a 10K RPM drive, and have ample CPU
and RAM. I need to write as much data as possible, as fast as possible.


Currently, I am using the StreamWriter. I am not getting anywhere near
the thru put I would expect. My code is something like:

For i = 0 To (MB.Length - 1)
StreamWriter.Wr ite(MB(i))
StreamWriter.Fl ush()
Next

Any recommendations on squeezing more performance?

J Wolfgang Goerlich

[guy]

RE: Committing Byte Array to Disk

suggest you move the StreamWriter.Fl ush outside the loop

"jwgoerlich@gma il.com" wrote:
[color=blue]
> What is the fastest way of writing a Byte array to disk? I have a 512
> MB array in memory. I am writing to a 10K RPM drive, and have ample CPU
> and RAM. I need to write as much data as possible, as fast as possible.
>
>
> Currently, I am using the StreamWriter. I am not getting anywhere near
> the thru put I would expect. My code is something like:
>
> For i = 0 To (MB.Length - 1)
> StreamWriter.Wr ite(MB(i))
> StreamWriter.Fl ush()
> Next
>
> Any recommendations on squeezing more performance?
>
> J Wolfgang Goerlich
>
>[/color]

[Rocky]

Re: Committing Byte Array to Disk

Use BinaryWriter instead.

bw.write(MB)



"guy" <guy@discussion s.microsoft.com > wrote in message
news:2D04CF28-BE5C-462F-B389-68133E2515BF@mi crosoft.com...[color=blue]
> suggest you move the StreamWriter.Fl ush outside the loop
>
> "jwgoerlich@gma il.com" wrote:
>[color=green]
>> What is the fastest way of writing a Byte array to disk? I have a 512
>> MB array in memory. I am writing to a 10K RPM drive, and have ample CPU
>> and RAM. I need to write as much data as possible, as fast as possible.
>>
>>
>> Currently, I am using the StreamWriter. I am not getting anywhere near
>> the thru put I would expect. My code is something like:
>>
>> For i = 0 To (MB.Length - 1)
>> StreamWriter.Wr ite(MB(i))
>> StreamWriter.Fl ush()
>> Next
>>
>> Any recommendations on squeezing more performance?
>>
>> J Wolfgang Goerlich
>>
>>[/color][/color]

[knarfm@speakeasy.net]

Re: Committing Byte Array to Disk

Try writing the whole array at one time.
I am not sure if it is faster but it works for me.

Public StatusData(255) As Byte

To Save:
Dim fnum As Integer = FreeFile()
FileOpen(fnum, Application.Sta rtupPath & "\Status.da t",
OpenMode.Binary )
FilePut(fnum, StatusData)
FileClose(fnum)

To Open:
Dim fnum As Integer = FreeFile()
FileOpen(fnum, Application.Sta rtupPath & "\Status.da t",
OpenMode.Binary )
FileGet(fnum, StatusData)
FileClose(fnum)

[Cor Ligthert [MVP]]

Re: Committing Byte Array to Disk

>[color=blue]
>
> Currently, I am using the StreamWriter. I am not getting anywhere near
> the thru put I would expect. My code is something like:
>
> For i = 0 To (MB.Length - 1)
> StreamWriter.Wr ite(MB(i))
> StreamWriter.Fl ush()
> Next
>
> Any recommendations on squeezing more performance?
>[/color]

Close all other programs which have disk access.

Cor

[jwgoerlich@gmail.com]

Re: Committing Byte Array to Disk

Much obliged for all the help! I am getting closer. StreamWriter takes
around 60 minutes. FilePut takes about two minutes (and really uses the
CPU!). BinaryWriter takes from 30-60 seconds. This is quite a
performance boost.

Yet, even at 30-seconds or 136 Mb/s, I am getting around half the thru
put from the disks that I expected. I suspect it is time to dig into
this from a hardware perspective.

Thanks again,

J Wolfgang Goerlich