Uninterrupted Power Supply issue

Hey,

Recently my 3-year-old Uninterrupted Power Supply (UPS) started to fail to kick in during power outages so I'm planning to replace it. I live in a country where outages are common so I need one. However, I noticed that the label on the UPS says that it has a maximum output of 500 watts while I have a 750 watt Thermaltake Toughpower power supply in my case. I have a have GTX 570 card and a E8400 processor and the UPS also feeds the monitor. I didn't encounter any problems with this discrepancy in wattages but when power went out, some kind of weird buzzing noise used to come from the power supply. This would keep sounding as long as the UPS supplied power by itself.

I don't know why it didn't occur to me before to do some research about this wattage business. The question is this: For my next UPS, do I need something like a 800-watt device or is something like my previous one enough? Thanks.

And it supplies power to the modem too, but I guess that's not too important.

Any help would be appreciated.

Thanks. Another thing confusing me is that here UPS devices are sold with VA specifications instead of wattage, which I assume means Volt-Ampere. For example I bought this UPS as 1000 VA, thinking it means watts and found out that the label on the thing says "maximum output= 1000 VA / 500W"

The buzzing noise may be common with UPS devices but the weird thing is that when the device kicked in, the noise came from the computer's own PSU, not the UPS.

Considering that the UPS will supply power to both my 750-watt PSU and the monitor and the modem, I'd do well to get something like a 800-watt UPS, I guess. Would more be required?

Considering that the UPS will supply power to both my 750-watt PSU and the monitor and the modem, I'd do well to get something like a 800-watt UPS, I guess. Would more be required?

Athawolfus