Parallel port performance

[Tarmo Pikaro]

Hi !

A little bit curious about parallel ports (LPT)
performance. I have tested windows 98 and windows 2000
drivers - w2k pp drivers seems to be something about 5
times slower than 98's. Is there a way to improove
performance using current microsoft drivers ?

Registry patch ?
Any custom driver to use ?

 

[Glenn - Audio&Media Europe nv]

Did you already try updating your mainboard's software?

 

[Bob I]

No expert on PP's but what settings were you using in Win2000 vs. Win98?
Also there is a MAJOR difference in the way the hardware is accessed
between DOS and NT. As far as improvement take a look at the LPT
settings in Device Manager, different configurations work better than
others based on the application and the hardware attached.

 

[Rick]

Hi !

A little bit curious about parallel ports (LPT)
performance. I have tested windows 98 and windows 2000
drivers - w2k pp drivers seems to be something about 5
times slower than 98's. Is there a way to improove
performance using current microsoft drivers ?

Registry patch ?
Any custom driver to use ?

The default config for a standard parallel port in Win2000 is to
not use an IRQ, just an I/O address. This usually translates into
slower performance. Luckily the port is configurable within
Win2000 Device Manager, you can specify to use an IRQ.

Also check your system bios setup and see if you can set the
port type to ECP or EPP instead of Standard. This will
substantially improve performance by making the port
bidirectional. Win2000 will install a proper driver on the
next reboot.

Rick

 

[Tarmo Pikaro]

I have tried different settings (IRQ / DMA), but they have
no effect on performance. Also I have tried to set up
manual port reading, using custom driver - it improoved 2
times reading speed, but still it is not the same speed as
in windows 9x. Guessing it have something to do with
IRQ/DMA optimization.

 

[Tarmo Pikaro]

My computer bios does not have any setting for parallel
(lpt)ports - it's kinda weird... I have found IRQ
reservation there , and my IRQ channel (IRQ7) seems to be
free (available).

Also I have tried to configure interrupt usage (try to
use, none, any) - but it also has no effect on lpt's
performance.

I don't need btw bidirectional port - only one way is
enough.

Any more guesses ?

 

[Tarmo Pikaro]

After analysing more I think that parallel port speed
degrade relates to DMA usage. Possibly w2k driver does not
use DMA even if DMA is provided to it.

Windows 98 becomes much slower if DMA is not used.

 

[Rick]

After analysing more I think that parallel port speed
degrade relates to DMA usage. Possibly w2k driver does not
use DMA even if DMA is provided to it.

Windows 98 becomes much slower if DMA is not used.

DMA transfer mode is not used for Standard or EPP port type,
just ECP. Win2K will only use a DMA channel if the port type
is ECP.

Rick

 

[Rick]

DMA transfer mode is not used for Standard or EPP port type,
just ECP. Win2K will only use a DMA channel if the port type
is ECP.

More accurately, Win2K will use a DMA channel only if the port
type is ECP.

Rick

 

[Tarmo Pikaro]

Windows NT gave me the same results as Windows 2000.
So I think the NT/2000 drivers are responsible for such
bottleneck.

 

[Eric Gisin]

| >
| > DMA transfer mode is not used for Standard or EPP port type,
| > just ECP. Win2K will only use a DMA channel if the port type
| > is ECP.
|
| More accurately, Win2K will use a DMA channel only if the port
| type is ECP.
|
What if the BIOS setting is EPP/ECP, can Win2K choose the better?

Anyone with problems should show kernel times in TaskMan, it will be very high
with EPP&STD.

 

[Rick]

| >
| > DMA transfer mode is not used for Standard or EPP port type,
| > just ECP. Win2K will only use a DMA channel if the port type
| > is ECP.
|
| More accurately, Win2K will use a DMA channel only if the port
| type is ECP.
|
What if the BIOS setting is EPP/ECP, can Win2K choose the better?

It's one selection, not two, i.e. EPP+ECP. This mode uses an
I/O address, IRQ *and* DMA channel.

Anyone with problems should show kernel times in TaskMan, it will be very high
with EPP&STD.

Yes, or at least higher than it is with ECP.

Rick