Power for A2000 Hard drive

[dougal]

Just a little advice needed here.

My GVP HC+8 did not come with the little floppy to molex power adapter, so i supplied power to the hard drive directly from the molex of the A2000's PSU.

It worked fine, no problems at all, but i recently found a floppy to molex connector and I am now supplying the hard drive with power from the HC+8.

It works great too like that and of course its easier to remove the card.

My question is, even though the hard drive IS meant to take its power from the HC+8, is this the best option or is the power supply better?

[Ral-Clan]

I can't speak from direct experience with the GVP card, but I have used an A2091 SCSI card (Zorro II) in the past in an Amiga 2000.  I read several places not to power the hard drive from the power adapter on the card itself, but to use a connector coming from the computer's power supply.

The reasoning was that the power supplied over the Zorro bus was too weak for the later hard drives.  It was fine for the intial 40-100MB hard drives but there was not enough juice to reliably power the models that came later.

[dougal]

I can't speak from direct experience with the GVP card, but I have used an A2091 SCSI card (Zorro II) in the past in an Amiga 2000.  I read several places not to power the hard drive from the power adapter on the card itself, but to use a connector coming from the computer's power supply.

The reasoning was that the power supplied over the Zorro bus was too weak for the later hard drives.  It was fine for the intial 40-100MB hard drives but there was not enough juice to reliably power the models that came later.

I heard the same thing about the A2091 but not about the GVP.

I am using quite an old 1GB Scsi drive on the GVP. It seems to be working fine being powered by the card but i might consider powering it from the PSU again if it could cause problems.

[Ral-Clan]

I heard the same thing about the A2091 but not about the GVP.

Well, I think it would be the same for the GVP as it's probably not the card that determines the amps, but the specifications (and limits) of the Zorro bus.  That's just a guess though.

I am using quite an old 1GB Scsi drive on the GVP. It seems to be working fine being powered by the card but i might consider powering it from the PSU again if it could cause problems.

Well, the 1GB drive would be considered a "late/modern" drive by A2000 standards, but if it's working fine for you then great.  Probably also has to do with how much power other devices in the A2000 are sucking.

[dougal]

Well, the 1GB drive would be considered a "late/modern" drive by A2000 standards, but if it's working fine for you then great.  Probably also has to do with how much power other devices in the A2000 are sucking.

Hmmm yes makes sense. My A2000 is pretty basic at the moment. The GVP is the only zorro card in it and its still with the standard 68000 cpu.

Possible that the 1GB 'newer' hard drive might draw less power than the older 50/100mb ones.

[JimS]

It depends on the physical size and maybe speed of the hard drive. The 12v for the motor is the issue. Powering it from the card, you're routing it through the motherboard traces, connector and the card traces first. Lots of places to fail, or to add resistance and drop the voltage.
For example, I used an old 500MB 5.25" full height drive--- in an external box --- but I would never try powering that through a card. ;-)