[PLUG] Why is it slower on a P4?

[AthlonRob]

On Tue, 2002-11-19 at 11:16, Derek Loree wrote:

> I don't see how, with 1Gig of RAM, the DMA state of the harddrive will
> make the mouse sluggish.  I really can't imagine any swapping going on. 
> Harddrive speed will affect application startup time, file copies and
> other read-write activities, but not the mouse movement or general
> application usage.

DMA doesn't directly speed up hard disk access so much as it may be
implied...

DMA reduces the amount of CPU power needed to access the hard drive.

If you're doing any kind of disk activity, your CPU utilization will
spike, and that can cause the mouse to jump around like was described.

In reducing the amount of CPU power used when doing anything with the
drive, DMA *does* speed up disk access, though.  I would guestimate as
CPU speeds increase, DMA vs non-DMA in terms of drive speed will become
less of an issue - but in overall system performance I think it will
remain relevant.

Rob

-- 
AthlonRob <AthlonRob at data.lm.ro>