128GB limit with USB/FW enclosures

[Santa]

oxford 128gb limit

I encountered an infamous limit of 128GB with hard disk drives
mounted in external USB2 or IEEE1394 (Firewire) enclosures.
My first impression is that stupidity must be a self-sustaining
high priority process. After a 32MB, 300MB, 2GB, 8GB limit we now
have a launch for a 128GB limit in PCs. Does anybody still beleive
this can be just fortuitous? Some new enclosures are able to go
beyond this and this renders the "old" ones obsolete and the
new ones attractive. :2gunfire:

Now, to be more constructive than the inventors of that feature,
I would like to understand exactly from where this comes.

Let me however kill the first wrong and well distributed idea.

While it is true that W2K or other OSes must have their 48-bit
LBA support enabled to go beyond 128GB, the limit I am talking
about does NOT come from the OS. The same 160GB IDE disk
connected on an internal IDE adapter is detected as 160GB while
it is truncated at 128GB when installed on an USB/IDE convertor
plugged in the same system.

Some people say that only ATA-6 enabled IDE controllers are capable
of 48-bit LBA support and that, since many of the USB/IEEE1394-IDE
do not support ATA-133 work as LBA limited hence 128GB limited
devices. So it would be a limit of the command set of non-ATA6 drives.

Other say that this is purely a limit in the register size of the convertor
chips.

Anybody has got the light of Galadriel to make things clearer
in this darkness? :idea:

Thanks.

 

[abacux]

oxford 128 gb limit

Look for a FW enclosure with Oxford 911 or 922 FW to IDE chip

**broken link removed**

 

[Kripton2035]

ads firewire 128 gb

well I currently sell 200Gb firewire drives for mac os with absolutly no 128Gb limit...
window$ strikes again...

 

[Pim]

xp usb ide 128gb limit

I'm using IOMEGA portable hard drive with a 250GB HD inside the enclosure. It reads and and functions as a 250GB drive in Win XP. This enclosure is equipped with both USB2 and firewire. I'm using the USB connection. Works great and no HD size limit here

/Pim

 

[drwho78]

oxford 922 drive limit 128gb

Some older USB to IDE chips has the 128G limitation. If you get newer enclosures with the newer chips like the ones abacux posted above, you should have no problems.

 

[Santa]

d850emv2 lba 48

While it is true that the new IEEE1394 or USB2 to IDE interface
chips do not exhibit this limitation when Windows 48-bit LBA is
enabled, it is unclear what is truly the limitation.

Some people say that ATA6 is needed to support 48-bit LBA, hence
to access more than 128G. To support this supposition, the new
interface chips support faster transfer modes and ATA modes
when they go above 128G.

However, there is an awfull mess with the ATA6, UDMA-100, ATA100
stuff versus 48 bit LBA capability.

I have seen that the Intel D850EMV2 doc says it is ATA-5 and ATA-100
and I believe the board will accept >128G drives.

So, where is the truth? What is really needed for 48-bit LBA support :?:

 

[Santa]

ads enclosure 128gb

BTW, I forgot:

OXFW911 doesn't go above 128G. Only OXFW912 and OXFW922 do.

Be careful when buying enclosures :!:

 

[Kripton2035]

usb ide 128gb

and the actual version of the chip is OXFW925... there are bugs with the OXF922 (on the mac for now...)