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[orcish75]

90KB/sec is very slow. I've got a GVP HC+8 card with a Guru ROM, connected to Mechy's native SCSI CF card reader on my A2000. I'm using a Transcend 16GB 133x CF card. I'm getting ~1.5MB/sec transfer rates on it regardless if I'm in 68000 or 68030 mode.

I had to disable synchronous transfers on the CF reader otherwise it would randomly lock up when copying large amounts of data. Disabling synchronous transfers didn't seem to have an impact on performance though.

The GVP card does SCSI DMA directly into it's onboard ram, I'm not sure if the A2091 does the same.

If you can, get a Guru rom for your A2091, it made a huge difference to my GVP HC+8 in terms of stability and performance. Unfortunately the adapters that the Guru rom plugs into are difficult to come by. The rom image itself is available on Ralph Babel's hompage http://babel.de/amiga.html but it won't work without the adapter.

Sorry I can't help you more..

[orcish75]

On my A1200 the CF is very quick. You are limited to the ~2MB/sec of the IDE port on the A1200 motherboard. What makes it quick is there is no seek time to speak of on a CF card, so it boots up in no time. My workbench is ready before my monitor has warmed up enough to display the image if I do a cold start.

Once in Workbench, it definitely "feels" a lot faster when accessing files and folders, however if you are going to copy a lot of files or large files, it will still take a while due to the 2MB/sec limit of the IDE port.

Just a warning if you do get an accelerator for your A1200, some CF cards don't initialise in time when you cold boot the A1200. It'll give you the insert floppy screen. Usually a Ctrl + A + A will allow it to boot, but it is irritating when it doesn't want to boot first time.

My Transcend 4GB and 8GB 133x cards boot fine on an accelerated A1200 but my Trancend 16GB 133x card won't cold boot, I have to Ctrl + A + A to get it to boot.

Unfortunately I don't have an A4000, so I don't know if it'll show the same symptoms of the A1200, especially as you have such a fast accelerator for it.

[orcish75]

Hard to get a picture of just the adapter.  I wonder if its just mapping  one chipsize to another 1 to 1, or if there is some logic on it...    

The adapter has a PAL to do some sort of address decoding as the GVP/A2091 card only has enough address lines for a 16KB ROM (27C128). The Guru ROM is a 32KB chip (27C256). I have tried to copy the PAL but naturally it  has the copy bit enabled so I couldn't copy it.

It is frustrating as the Guru rom is no longer commercially available. I'm always happy to support any hardware vendors such as Jens and Ralph but when they decide to no longer support a device, they should make things like the PAL image available to everyone so that we can at least make the adapters ourselves.

[orcish75]

I can get 7.0 ROMs for my card - its the rev 8 WB chip that is the hard one to find.    

Mechy sells them on his website, not too expensive either, it's the AMD version which is the same as the -08 WD version.

http://a4000t.com/store/index.php?main_page=product_info&products_id=210&zenid=ce58e464a2906f5a92768b7e20cdacd1

Cheers

[orcish75]

It's a pleasure!

I'll swap my Guru rom for the regular v4.15 GVP rom and set my A2000 to 68000 mode and do some benchmarks for you. I know it's not exactly the same as your A2091, but it'll at least be an indication of what you can expect.

The main reason I went the CF route is that with all the expansion cards and 7200RPM SCSI drive in my A2000, the A2000 was getting REALLY hot. I could barely touch the HDD. After swapping it for the CF solution, it was running MUCH cooler but it also made my A2000 much faster. Not in terms of raw speed, but workbench operations are much snappier, opening a drawer with lots of games in it is now much quicker.

I'd definitely recommend going the CF route over a normal HDD.