What is the biggest hard disk that you can use with a Microbotics HardFrame?  I read in a magazine ad that there was no limit in hard disk capacity.  Is this true?  Also, is it true that this is the fastest SCSI controller available for the Amiga 2500?  About 12 years ago I had a Microbotics Hard disk on my Amiga 1000.  I never had any problems with it and it was fast.  I do recall that I really admired it.  The Microbotics HardFrame SCSI Controller card use an Adaptec controller IC.  Is it better then the Western Digital controller IC found on the A2091 card?     :roll:

@DoomMaster:

It might be able to support harddrives larger than 4GB if the device-driver supports the SCSI_Direct commands.

As it is a ZorroII-card, the maximum obtainable transferrate will be 7.14*(16/8)/4 = 3.57MB/sec (busclockspeed * (buswidth / bitsinbyte) / busclocksperbuscycle)). Ofcourse it can be slower than that, but it cant be faster.


/Patrik

@DoomMaster:

The reason why scsi controllers on accelerator cards like the Blizzard2060 are better speedwise than all ZorroII-based scsi controllers is because they can do DMA transfers directly to/from the 32-bit memory on the accelerator card and thus avoiding the bandwidth bottleneck ZorroII poses.

Another bonus of using the scsi controller of an accelerator card like the Blizzard2060 instead of a ZorroII based scsi controller is that you leave the bandwidth of the ZorroII-bus free to be used by other expansion cards which might need it.

The only time you should choose a ZorroII based scsi controller instead of the scsi controller of an accelerator card is if the hardware/driver doesnt function well.

The Blizzard2060 uses the QLogic FAS216 scsi controller IC.

I dont know which one of the Adaptec or Western Digital controller IC is the best. The easiest way to figure that out would be to compare the performance of two boards based on these ICs in the same system.


/Patrik

@DoomMaster:

Please post the results if you try it out.


/Patrik