Amiga Hard Drive size limitations

[spaceman88]

Hi,
I know Amiga's have a problem around 4 GB, but I have a 4.32 GB (Fujitsu MPC3043AT) drive that I partitioned into 3 sections (500MB and 2 just under 2 GB). Is this going to give me problems? I'm using an A4000 and installing WB 3.1. What is the exact limit, 4.0, 4.2, 4.32? Hopefully I'm just under the wire :-).
Thanks

[Thomas]

The exact limit is 4,294,967,296 Bytes a.k.a. 4.29 GB a.k.a. 4.0 GiB.

You can use Check4GB to check if the partitions are inside the limit.

You can use FixHDDSize to limit the harddrive to 4 GiB so that you don't need to care when creating or moving partitions.

You can also manually limit the harddrive to 4 GiB if you overtype the geometry by these values:

cylinders =  8322
heads = 16
blocks per track = 63
blocks per cylinder = 1008

[Zac67]

Exactly. As soon as a partition overlaps the 2^32 bytes barrier the data written to the overlapping  sectors will wrap around and destroy your RDB, the beginning of your first partition etc.

With a slightly-over-4GB drive it's not worth the trouble but otherwise check http://www.youngmonkey.ca/nose/articles/NewTekniques_9810/AmigaInMotion.html

[darkage]

Many thanks for the link!

I've learnt something new!

[ChaosLord]

If u install the correct patches, or use a reasonably updated AmigaOS install, then the only hard drive size limitation is 2000 GB, which is the same as Windoze XP.

[Ral-Clan]

Since I recently got a 9GB hard drive I've yet to install, I have some of the same questions.

If I keep all my partitions on this drive less than 4GB, it should be okay (i.e. Workbench partition = 3GB, Partition B = 3GB, Partition C = 3GB)?

The YoungMonkey article linked to above seems to suggest you cannot use the later partitions (that occur above the drive's 4GB mark) even if the partitions themselves are smaller than 4GB (the author suggests labelling them as DEAD partitions and to never format them).

I know OS3.5+ has large drive support, but I want to make sure I understand what would happen if I used an older version such as 2.1 or 3.1.

I guess what I don't understand is: was the 4GB limitation on hard drives for each partition (i.e. as long as all partitions were under 4GB on a drive of any size you were safe), or was it a 4GB limit on the whole drive (i.e. no matter how carefully you had partitioned the drive, as soon as it went beyond the 4GB mark, regardless of the partition it was writing to, the drive would wrap around).

[Thomas]

http://thomas-rapp.homepage.t-online.de/4gb_faq.html

[Tenacious]

Excellent FAQ Thomas!  I don't know how long this has been available, but, I wish I had had this information years ago.

Thanks again and good job!

[paul1981]

http://thomas-rapp.homepage.t-online.de/4gb_faq.html

In the History section of  the SFS_OLD.guide in the current aminet distribution (1.277), it says that from version 1.58 BETA, SCSI direct is turned on or off automatically:

"There is no seperate SCSI direct version of SFS anymore.  SCSI
direct will be used automatically when no NSD 64-bit or TD64
support is found (SCSI direct users: please let me know if this
works correctly for you -- use the SFSquery tool to find out if
SCSI direct is being used)."

I know this was an old beta version, but does this still apply to the present versions 1.277 - 1.279?

I'm currently fiddling around myself with installing an 80GB on my other 1200 (68040/40/16MB WB3.1/3.0 ROMS) and it appears that using SFS 1.277 and frap http://aminet.net/package/disk/misc/frap_v1.0 I am able to utilize correctly the full drive. Only requirement for frap is that ROM is in RAM.
I made two partitions of 1024MB, and a third of 72GB.  This must be using scsi direct right?  It seemingly works, but I'll have to do more testing within the next few days when I get the time. Check4GB says it's okay...

I also tried the scsi.device 43.24 instead of frap, but that appears to half the RAW read transfer speed in sysinfo to something like 1.1MB/s from 2.1MB/s where as FRAP seems to give a nice boost to about 2.3MB/s.  Does anyone know why scsi.device 43.24 is running slow for me?
I'm aware of the cosmos scsi.device for use with PFS3, so I might give that a try as well at some point.

[JimS]

If you have a really old scsi card, you could run into limits with it's firmware. I had some 2 GB drives which would not work on my 2091 controller, but worked fine on the GVP '030.

[Nostalgiac]

wow! while i knew (urm..some of) this... that is an excellent and very useful writeup Thomas !

cheers
TomUK

[spaceman88]

Thanks for all the info and the links. I'll try to limit it to 4.29 ;-0.

[curtis]

As a refresher, could someone remind me on the size limits for WB 1.3 and 2.x?

Thanks,

Curtis

[Thomas]

1.3 does not have any limit because it does not contain any drivers for harddrives. Limits are defined by the firmware of your harddrive controller.

2.04 does not contain HDD drivers, either.

2.05 is similar to 3.0, it contains the same scsi.device version (36).

[Etherweet]

i think i know the answer already..

if i have an a2000 with a 2091 controller i cant do more than 512 mb on any drive no matter what size.

and yet another one - can you use different filesystems for each drive... like the original ffs on a 340 mb hard drive and nsd on a 4.3 gb on the same controller?

i'm thinking the answer is no to both.

i have a stock 2000hd / 2091 and a 3000t -040 - both with growing pains.
i am ok with mounting a linux server for storage space.

(also refitting an atx power supply to the 3000)

thanks