View Full Version : 137 GB barrier

06-13-03, 05:49 AM
Ok, I've gathered this from scattered sources: the addressing scheme used by BIOSes to reference points on a hard drive until very recently only supported drives up to 137 GB, because that's the maximum size/reference their address data could hold.

Apparently, recent bios flashes and windows upgrades improve this by instituting a new addressing structure.

Here's my situation: I have a hardware RAID setup and 2 80 gig WD JB drives on an nf7-s 2.0. I'm going to be making a raid 0 array, which means a 160 gig array.

So, here's my question: Does this 137 gig barrier affect me? I'm guessing perhaps not, because each drive only has 80 gigs of address space to work with, well within the limit. However, I'm not sure at what 'level' the check is done.

If the RAID/IDE controller reports the setup to the bios as a 160 gig setup, then it would seem that I would be affected. If, however, the bios recognizes each drive seperately, I wouldn't.

In any case, windows might have a problem with this, since the RAID is done in hardware, as far as windows knows, I have a 160 gig drive.

So, first, does anyone know if this affects me? Second, the only way to fix windows for that, if it does affect me, is through patches and service packs.

Second, can I install windows on the setup (and have it only recognize 137 gig), and then patch it, and have it just correct itself and see all 160?

06-13-03, 06:22 AM
You can install win2000/XP but when installing it will ask you to press F6 for scsi/raid drivers.

Bios accesses the drives as 80GB so they will work up to this point. But when you create a raid-0 of them the bios will still be able to access them but it also construct a new virtual drive of 160GB. So if it has the 137GB problem it will surface.

Now any bios supporting raid most likely doesn't have the problem. In addition to that most boards in the recent 2-3 years also don't have the problem.

Now that are my thoughts. If I am wrong please correct me.

06-13-03, 07:32 AM
I am 99% certain that you'll be able to set up your array without a hitch.

The 137GB limit only comes into play if the drive is installed on the channel 0 or 1 IDE bank. While onboard RAID controllers connect to the drives through an IDE or SATA cable, as far as the motherboard is concerned the controller is a PCI devise, and hard drives connected through a PCI controller don't have to deal with the 137GB limit.

And if you are running WinXP, Microsoft has come up with a way to enable 137GB+ drives on IDE0 and IDE1. Read all about it at: