WDF vs. WDM for PCIe card

NTDEV
1

Hello,

I’m about to start device driver development for a PCIe card.

Basically this card gets data from a 3Gbit/sec input and writes it to physical RAM in the PC.

This RAM is pre allocated using AllocateCommonBuffer.

I started writing device drivers 3 years ago with WDF (KMDF only).

My collegue claims that WDM has better performance and is more suitable for cards with fast input.

Is he right ?

Will Microsoft update WDM forever or is it legacy ?

Thaks,
Zvika.

2

Is this a custom device or will it operate in a windows predefined device class (like networking)?

d

-----Original Message-----
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of xxxxx@gmail.com
Sent: Thursday, March 17, 2011 3:04 PM
To: Windows System Software Devs Interest List
Subject: [ntdev] WDF vs. WDM for PCIe card

Hello,

I’m about to start device driver development for a PCIe card.

Basically this card gets data from a 3Gbit/sec input and writes it to physical RAM in the PC.

This RAM is pre allocated using AllocateCommonBuffer.

I started writing device drivers 3 years ago with WDF (KMDF only).

My collegue claims that WDM has better performance and is more suitable for cards with fast input.

Is he right ?

Will Microsoft update WDM forever or is it legacy ?

Thaks,
Zvika.

NTDEV is sponsored by OSR

For our schedule of WDF, WDM, debugging and other seminars visit:
http://www.osr.com/seminars

To unsubscribe, visit the List Server section of OSR Online at http://www.osronline.com/page.cfm?name=ListServer

3

Your colleague does not know what he is talking about. WDF will be able
to produce the same performance as WDM and since you are not wasting
your time on dealing with all the boiler plate you have more time to get
the performance level up to what you want.

Using WDM for a new PCI card driver is one of the stupidest things a
developer could do. I suggest you let your boss know he has an idiot
working for him.

Don Burn (MVP, Windows DKD)
Windows Filesystem and Driver Consulting
Website: http://www.windrvr.com
Blog: http://msmvps.com/blogs/WinDrvr

“xxxxx@gmail.com” wrote in message
news:xxxxx@ntdev:

> Hello,
>
> I’m about to start device driver development for a PCIe card.
>
> Basically this card gets data from a 3Gbit/sec input and writes it to physical RAM in the PC.
>
> This RAM is pre allocated using AllocateCommonBuffer.
>
> I started writing device drivers 3 years ago with WDF (KMDF only).
>
> My collegue claims that WDM has better performance and is more suitable for cards with fast input.
>
> Is he right ?
>
> Will Microsoft update WDM forever or is it legacy ?
>
> Thaks,
> Zvika.

4

xxxxx@gmail.com wrote:

I’m about to start device driver development for a PCIe card.

Basically this card gets data from a 3Gbit/sec input and writes it to physical RAM in the PC.

This RAM is pre allocated using AllocateCommonBuffer.

I started writing device drivers 3 years ago with WDF (KMDF only).

My collegue claims that WDM has better performance and is more suitable for cards with fast input.

Is he right ?

No. Perhaps he misinterpreted a conversation about UMDF. I agree with
Don – I would never write a PCI driver today that was not KMDF. It is
a far more productive environment for the developer.

Will Microsoft update WDM forever or is it legacy ?

All KMDF drivers are also WDM drivers. WDM is not going away.

–
Tim Roberts, xxxxx@probo.com
Providenza & Boekelheide, Inc.

5

I hate to make this into a thread with a ton of “me too” answers… But, ah, me too.

Peter
OSR

6

But…real men don’t use frameworks…

Seriously, how ridiculously it may sound, there are guys writing drivers in ASM… I have once written a “serious” application (fast print utility for P-CAD files) almost completely in MASM for 80286. That was around 1992.

7

Sure people did, and some of us were smart enough to move off well
before that. In the early 80’s I wrote a network protocol stack in C,
another group in the company wrote one in ASM. I kept beating them
since when I found a performance problem I put on my compiler hat and
helped that group speed up the compiled code. Bottom line is a good
optimizing compiler has been able to keep up or beat assembler coders
for most things for over 30 years.

But to get back to WDF, there are only rare cases when it will not be
better than WDM. Remember you can always put some of the model into WDM
when you need it.

Don Burn (MVP, Windows DKD)
Windows Filesystem and Driver Consulting
Website: http://www.windrvr.com
Blog: http://msmvps.com/blogs/WinDrvr

“xxxxx@broadcom.com” wrote in message
news:xxxxx@ntdev:

> But…real men don’t use frameworks…
>
> Seriously, how ridiculously it may sound, there are guys writing drivers in ASM… I have once written a “serious” application (fast print utility for P-CAD files) almost completely in MASM for 80286. That was around 1992.

8

Dear Mr. Holan,

This is a custom device. It has nothing to do with networking or disk
handling.

Thanks,
Z.V

----- Original Message -----
From: “Doron Holan”
To: “Windows System Software Devs Interest List”
Sent: Friday, March 18, 2011 0:09
Subject: RE: [ntdev] WDF vs. WDM for PCIe card

Is this a custom device or will it operate in a windows predefined device
class (like networking)?

d

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of xxxxx@gmail.com
Sent: Thursday, March 17, 2011 3:04 PM
To: Windows System Software Devs Interest List
Subject: [ntdev] WDF vs. WDM for PCIe card

Hello,

I’m about to start device driver development for a PCIe card.

Basically this card gets data from a 3Gbit/sec input and writes it to
physical RAM in the PC.

This RAM is pre allocated using AllocateCommonBuffer.

I started writing device drivers 3 years ago with WDF (KMDF only).

My collegue claims that WDM has better performance and is more suitable for
cards with fast input.

Is he right ?

Will Microsoft update WDM forever or is it legacy ?

Thaks,
Zvika.

—
NTDEV is sponsored by OSR

For our schedule of WDF, WDM, debugging and other seminars visit:
http://www.osr.com/seminars

To unsubscribe, visit the List Server section of OSR Online at
http://www.osronline.com/page.cfm?name=ListServer

—
NTDEV is sponsored by OSR

For our schedule of WDF, WDM, debugging and other seminars visit:
http://www.osr.com/seminars

To unsubscribe, visit the List Server section of OSR Online at
http://www.osronline.com/page.cfm?name=ListServer