I have a situation where I will be powering a passive backplane containing several Gigabyte i-Ram RAMDISKS. I am looking at a 1000-1500VA UPS for it. Any idea with the cards might draw from their ATX power supply? Each card has (4) 1GB DDR DIMMs on them, for a total of twelve DIMMS. The cards also contain a standard SATA controller. They are universal cards that will take either 3.3 or 5 volt power from the slot. The backplane has a PCI Bridge chip on it, but nothing else - no Single Board Computer or anything like that. The i-RAM cards only draw power from the PCI slots. They do not require any host intelligence, so basically the backplane is a glorified power supply rail.

I'm trying to get a feel of how long a 1000VA UPS would power the backplane. Again, there are no CPU's, hard drives, North Bridges, LAN controllers, video cards, or anything like that. Just a PCI bridge chip (no heatsink on it, so it must not draw much).

Any thoughts would be appreciated. I am hoping to get something that would go 8 hours or so, if that is possible. Basically it's only going to draw 3.3 from the ATX supply connected to it. There are no 12 volt devices on this backplane. Thanks.

Each card is about 30Watts (pretty sure)
And yes you can get 8Hrs + from a good UPS

Thanks for the reply.