PIO2 A4000 Mod not any faster?

[grelbfarlk]

I finally burnt some Gals with the PIO2 mod for the A4000 that seem to boot, however it doesn't really seem any faster testing with Sysspeed or RSCP.

Getting about 2.5MB/s with a Sandisk Ultra 32GB CF on a mostly empty drive.

Any suggestions why it isn't faster? The CF adapter I have used elsewhere like in a CSPPC with a SCSI Ultra to IDE adapter so I know that will run in excess of 19MB/s.

And the CF card will run 50+ MB/s.

This is the original IDE PIO2 mod from amigawiki

As the updated one my burner and jedutil (though I don't know if this works) don't seem to like it. Either complain invalid format or no start character.

Configuration goes:
A4000D
A3640 w/060@50Mhz with Speedgeeks 030 state machine
64MB Mod
Mediator
(Some PCI cards)
32GB Sandisk Ultra CF w/PFS3
scsi.device is 43.45.

HDD Mask setting is 0x7FFFFFFE or 0x7FFFFFFC - same results either way.
Maxtransfer is:0x1FE00

Also disabled the Sonnet library in case this was somehow affecting it.

[grelbfarlk]

After a bit more reading, the people who reported a good gain were all using mechanical 7200 RPM drives that presumably had some cache. PIO2 Mod gains are minimal or very small with CF cards, at least what some people say.

[grelbfarlk]

With the GVP TRexx-1 in the system the max read speed went up to 3.4MB/s. With a CSPPC or some other faster accelerator, even higher speeds should be seen, but they'd all have much faster onboard SCSI.

[patrik]

Does this CF card support multiple transfers? If not, might that be the reason for not seeing more of a difference? (just a potential idea, I do not know how large effect it has).

More info:
http://eab.abime.net/showthread.php?p=1209708
http://eab.abime.net/showthread.php?p=1287165

[grelbfarlk]

Originally Posted by patrik

Does this CF card support multiple transfers? If not, might that be the reason for not seeing more of a difference? (just a potential idea, I do not know how large effect it has).

More info:
http://eab.abime.net/showthread.php?p=1209708
http://eab.abime.net/showthread.php?p=1287165

Thanks I'll check that.


What I'm getting now seems like it's about correct. These people reported:

Storm on Amibay reports:

DH0: from 2.9Mb/s to 4.8Mb/s
DH1: from 3.2Mb/s to 6.5Mb/s
DH2: from 3.2Mb/s to 6.7Mb/s
With a cyberstorm mk2 060/72 on a 40GB Seagate IDE hard drive.

Or Hooverphonique here:
@33MHz PIO0 PIO2
Master 2.3MB/s 2.6MB/s
Slave 1.9MB/s 2.4MB/s

@37MHz PIO0 PIO2
Master 2.5MB/s 3.0MB/s
Slave 2.4MB/s 2.4MB/s

With an A3640 @33MHz or @37MHz.