PPC G5 won't show main hard drive after upgrade to larger 1TB disk. Please Help!

This may be a problem related to SATA speed. PPC G5's were set up to run SATA 1.5 GB/sec. The new WD drives are made to run SATA 6 GB/sec. The PPC may not be able to "downgrade" so that it can recognize and run the faster drive at a slower rate. In some cases, you can put a jumper on the drive to "slow it down"; not sure on this, you may find something at the WD website.

Dennis

Hi, Dennis is correct. 🙂

The G5s can often negoiate a later SATA version drive down to SATA 1.5 Gb/s If it first finds a real SATA 1.5 Gb/s drive in the first position.

Just keep the new drive in the second position, there should be no noticeable difference in operation.

You likely can boot from the new drive with a proper drive in the top slot.

Some SATAII 3 Gb/s drives will work fine in the top slot, some like WD drives may require a jumper on pins 5 & 6 to slow them to G5 spped.

I just set up and ran a test. I have a 9-year old PPC dual-2GHz G5 (PowerMac 7,2). I run with a 2-harddrive arrangement - the top (A) position has my Start-up drive with all of the applications and the lower (B) position is the Data drive with all of the User files. Both drives are older SATA I 1.5GB/sec. I have a brand new WD Black 1.0 TB SATA III 6 GB/sec drive; I put this into an external firewire cabinet, used CCC to clone my Startup drive to it and then put this new drive in place of the original Startup drive in the A position. I turned the machine on but it would not recognize the drive and would not boot. I shut the machine down, and installed a jumper across pins 5 & 6 on the back of the drive; according to WD, this will slow a 6 GB/sec drive down to 3 GB/sec. I left this drive in the A position, closed up the cabinet, and turned the computer on. This time, the machine recognized the drive and booted right up. I don't know if it's because the older machines can recognize SATA II but not SATA III, or if it's because I still had the older Data drive in the B position. Regardless, it's working on my G5 right now.

Hope this helps.

Dennis

Great work, thanks! 🙂

If I were to guess, it'd be because the current WD firmware can negotiate SATAII to SATAI, but can't negotiate SATAIII to SATAI.

Whatever it is, it works. And it may actually help me with a problem. My Startup drive is the original drive that came with the computer, a Maxtor 160 GB. I've been having some problems with the machine acting up, wasn't sure if it was hardware of software related. My plan was to back everything up, wipe the system clean and re-load. As part of that, I wanted to get a new hard drive, just in case the problem was the Maxtor finally giving out. Now that that I know I can use a SATA II (or a III jumpered down), I've got plenty of drives to pick from.

Dennis

Great, I'd not recommend a Green Drive.

I swapped my boot drive (older Seagate) with my Western Digital Caviar Blue yesterday because it was loads faster. Same thing happened to me. I even had a RMA with Western Digital set up to mail out today until I remembered the jumpers. Jumped pins 5 and 6 and it booted just fine.

Thanks for the report Laish! 🙂

Why not a Green drive? I've got a WD Red and a couple of Blacks that I've had in service for a few months with no problems but I haven't tried a Green or a Blue yet. Or is there another thread here somewhere that covers this in more detail?

TIA,

Dennis

Well, some Greens might be OK, some go to sleep on their own when they shouldn't, & most are slower than Blacks & Blues.

OK, thanks. The Red that I have seems to be slower than the Blacks but I guess they're supposed to be that way. I only use it for my nightly back-up in an external housing, not as a routine data drive, so it's not a problem.

Dennis

Ah, yes, for backup should be fine.