CF / SD and large drives FAQ

[fgh]

It depends on what you are doing on the amiga but in general write speed is much less important than read speed on amiga use cases nowadays.
You’ll have both random and sequential reads, again depending on what you do.

Not having moving parts (= seek time) often contributes as much as the increased top speed of your flash media towards the percieved speed increase vs old harddrives though.

And a 20mb/s rated card doing 0,1mb random writes sounds unusually slow.

[jbenam]

Originally Posted by fgh

It depends on what you are doing on the amiga but in general write speed is much less important than read speed on amiga use cases nowadays.
You’ll have both random and sequential reads, again depending on what you do.

Not having moving parts (= seek time) often contributes as much as the increased top speed of your flash media towards the percieved speed increase vs old harddrives though.

And a 20mb/s rated card doing 0,1mb random writes sounds unusually slow.

Not much really, just extracting archives, WHDLoad and a bit of random programs here and there.

This is an old Samsung 16GB SSD I had laying around. I was wondering if it was worth putting it in my A4000 in place of my current CF.

So I benchmarked it and I got sequential R/W speeds of 100/50 MB/s respectively, and then 25 MB/s for random reads, while random writes are just 0.2MB/s. I've just rechecked it on another PC and I got the same result. I'll try to benchmark my CFs and SDs for random writes when I get a bit of time.

[dreadnought]

My ACA500+ has just arrived. I can't use it though, because I was dumb enough to confuse CF cards (which I have 0 of) with SD cards (which I have plenty of). Basically, I have been using only SD/MicroSD for so long now that I forgot there's another standard in town.

So now I have to sort this out, but quick look at the prices got me a bit worried. These things are not cheap, and my budget is already a bit shaky after ACA itself. Do you think I could get away with just buying a couple of CF -> SD adapters? Do these things work in this scenario?
And could I then read the SD card via WinUAE in my PC? I have the SD -> USB adapter but would have to buy the CF ->USB one.

[demolition]

I use a CF-SD adapter in my ACA500plus and it works fine. And yes, you can just take the SD card out and read that in the PC.

[dreadnought]

Thanks! I will give it a whirl then, save a chunk of cash this way.

[A500]

Originally Posted by Toni Wilen

16G and 32G "silver" Sandisk Ultra 50MB/s CF cards (https://www.sandisk.com/home/memory-...a-compactflash) use "illegal" CHS geometry = full capacity is available without scsi.device update with DirectSCSI filesystem.

16G confirmed here: http://eab.abime.net/showthread.php?t=85688
I ordered 32G version after I saw above post, it arrived today and I can confirm that it also uses "illegal" CHS geometry. (62041/16/63, "HDX13.04SDCFHS-032G")

Thank you very much for this information Toni! I have two such CF cards (16Gb), and they kept showing partitions over 4Gb as NDOS after partitioning, formatting, installing WB3.1 and rebooting under PFS3AIO3.0 + SCSI.DEVICE 44.20, the latter of whicih I obviously used to avoid the same problem.

Just to be clear, with PFS3AIO 3.0 and scsi.device 40.12 everything works fine. I made two partitions, 512Mb for System: and the rest of the 16Gb card as the second partition. Thanks again!

[thomas]

scsi.device V44 does not avoid anything. It's a hack, it is buggy and it is confirmed to make hardrives disappear.

What you need to fix the 7.8 GB issue is either scsi.device V43.43 from OS3.9BB2, possibly with Toni's LBA48 patch, or scsi.device V46 which is part of OS 3.1.4.

[A500]

Originally Posted by thomas

scsi.device V44 does not avoid anything. It's a hack, it is buggy and it is confirmed to make hardrives disappear.

What you need to fix the 7.8 GB issue is either scsi.device V43.43 from OS3.9BB2, possibly with Toni's LBA48 patch, or scsi.device V46 which is part of OS 3.1.4.

Thank you Thomas, good to know! I'm still quite new to using CF cards as Amiga HD so all information is most welcome.

[manicx]

Ah, got into this and now I am lost.

I have an A1200 with a 4GB CF card, SFS formatted. OS is Workbench 3.0, installation I have from the 90's. Have some extras like MagicWB and MUI.

Got a new 8GB CF from a friend, never used it, so it is brand new. I cleaned with diskpart, inserted in my CF card reader, mounted with WinUAE, no luck to see >4GB partitions. SFS is not enough.

Any suggestions what to do? I prefer not to start upgrading Workbench versions (don't mind devs) since my installation is pretty solid.

[fgh]

Indeed, sfs is not enough.
original kickstarts (scsi.device) only support 4G unless you use ‘directscsi’ mode, which sfs (after v1.84) does not support. So you need to patch scsi.device, or use pfs3ds or pfs3aio.

[manicx]

I did try to get the patched scsi.device from ClassicWB v43.24 (as per the instructions in the website for ClassicWB), copied to my DEVS, changed the Startup-sequence to

IF EXISTS DEVS:scsi.device
  C:LoadModule DEVS:scsi.device
ENDIF

version scsi.device shows the correct version (43.24)

and I went to HDToolBox same result, sees up to 4GB and if I use the bar to pass that, it restarts counting from 0. HDToolBox is set to uaehf.device. I did try HDInstTools, but no matter if I change (and uncomment) to uaehf.device, it cannot see any drives including the hdf.

Not sure if the above is the right procedure but didn't work.

[manicx]

I did use the info from this post

http://eab.abime.net/showpost.php?p=831346&postcount=14

to

a) Install the latest pfs3aio using 0x50465303 as identifier
b) patch the scsi.device

Still no luck. I even tried with ClassicWB, same result. Not sure what else should I do? Could it be the OS (WB3.0) or the HDToolBox (40.3)? When I try partitioning using my OS3.5 or OS3.9 hardfiles, partitioning works. But when I use my Amiga 1200 hdf or even ClassicWB (with patched scsi.device and pfs installed, I cannot get passed the 4GB limit.

CF card is a Transcend. Entering despair mode!

[Jope]

HDToolBox will always wrap around at 4GB but that doesn't mean the partition will be smaller - you just need to calculate the size manually. HDToolBox from OS3.1.4 has this fixed.

[manicx]

Thanks Jope. I asked a friend to come and check with HDToolBox 3.1.4 since I don't have it. We just tried and indeed, HDToolBox sees everything properly and partitions the drive. However, when I try to format the disk, it give me <4GBs. I checked in ClassicWB and size of the formatted disk seems ok. I really don't know what else to look for. I have patched scsi.device (SCSI_v44_20_Doobrey), I did try NSDPatch, PFS3AIO. If it works in ClassicWB and not in my WB, there must be something wrong.

If anyone can help, I am willing to share my hdf...

[fgh]

Always quick format, as full format will always fail above 4GB on os 3.1 or older.

Hdtoolbox will get the correct card size in winuae or real hardware for 8GB cards when you ‘read configuration’ so that should be fine here.

The fact that the partiton size resets when you slide above 4GB in hdtoolbox can be ignored, as Jope said. It does not affect the stored partitions. ( just mentally add 4GB to the presented value)

With pfsaio your setup will work fine, even without a scsi.device patch.

[thomas]

There are several places where a 4GB limit appears. Some can be fixed, others can't.

The most important place is the interface between the device driver (scsi.device) and the file system. The standard interfaces used a 32bit offset which wraps around at 4GB. This is dangerous and must be fixed. If can be fixed by upgrading scsi.device and/or using a new file system. This is what you did, so you are safe. You can fill the partitions with files and these files are safe.

Another place is the caluclation and display of free space. AmigaDOS reports it as number of sectors and sector size. This is safe, too. But programs try to calculate the free space in bytes by multiplying these two values using 32bit math. This calulation wraps around at 4GB, too, so you'll never see more than 4GB free space. HDToollbox does it. Workbench does it.

It cannot be fixed. You have to use a newer version of HDToolbox and a newer version of Workbench to see the correct values.
But it's not dangerous, either. It's only annoying. Only the display is wrong. The partition itself is safe as expkained above. You just don't see the real amount of free space, but you can use it.

BTW, scsi.device v44.20 is not a good choice. If it works it seems to work well, but for many people it does not work. It makes harddrives disappear and/or causes read errors.

[manicx]

Ok, a sum up in pictures:

HDToolBox from 3.1.4 shows correct size:


Formatting shows 3222:


OS displays 2,745


OS 3.5 displays 6,6 (there are two partitions and the other partition is 300MB)


So if it is just a display issue, frankly, I don't care. I will never fill it, just need more space for some WHDLoad games.

Thomas, which is the most stable patched scsi.device to use?

[thomas]

Personally I would stay with OS 3.9 BB2 (43.43) unless I need more than 128 GB, then I would probably migrate to Kick 3.1.4 (45.7).

[fgh]

Originally Posted by thomas

Personally I would stay with OS 3.9 BB2 (43.43) unless I need more than 128 GB, then I would probably migrate to Kick 3.1.4 (45.7).

43.43 works fine when it works, but it fails with all drives/cards larger than 4GiB that report lba48 capability. That’s why I recommend 43.45.
(See ‘OS 3.9 Boing Bag 2 issue‘ in the FAQ)

[thomas]

Originally Posted by fgh

it fails with all drives/cards larger than 4GiB that report lba48 capability.

The drives I tested (well, two) worked fine unless you actually try to access beyond the 128GB limit.