Jeff
I think you are making many
assumptions about the application... In my case, it was BIOS. BIOS
is by nature single threaded, CPU utilization is not a factor. BIOS does
however benefit from UDMA since some drives can now sustain up to 40MB/s.
So, regarding your points:
1. Yes
it is an SFF-8038 host
2.
Incompete easily in transfer rate, runs faster than anything windows has to
offer, and CPU utilization is 100%. Keep in mind that polling is faster
than interrupting. If all you want to do is stream data, you
poll
3. Cpu
utilization is directly proportional to the polling rate...
4. If
you were using an ADMA based host (project 1510d) you would not have any of
these issues.
-----------------------
Curtis E. Stevens
Pacific Digital
Corp.
2052 Alton Parkway
Irvine, CA 92606
Phone (949) 477-5713
Fax (949) 252-9397
E-Mail: [EMAIL PROTECTED]
WEB: www.PacificDigital.com
The face of a child can say it all, especially the mouth part of the face...
-----Original Message-----
From: Wolford, Jeff [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, January 22, 2002 12:04 PM
To: [EMAIL PROTECTED]
Subject: [t13] UDMA without INTR
From: Wolford, Jeff [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, January 22, 2002 12:04 PM
To: [EMAIL PROTECTED]
Subject: [t13] UDMA without INTR
Curtis,
I
chopped all the other stuff out
OK Jeff, this
E-Mail is way too long to read. However, just looking @the first point, I
did UDMA without using the interrupt. The interrupt is truely not a
requirement for UDMA.
[JWW>]
[JWW>]
1) Please describe in high level and was it using a SFF-8038 type
host ?
2) Can a non-INTR driven UDMA compete with one that does in
either:
a)
Transfer Rate
b) CPU
Utilization
3) If it involves ANY
polling are you not either
a) Consuming the CPU that you are trying to off load with
UDMA
b) Have a large gap after the data transfer is
completed to when you
checked for status ?
Jeff
