You Have Chosen.Us

Over in my I have a new computer topic I mentioned I’d also ordered a UPS, and you’re about to find out why.

As I previously mentioned, I ordered a Promise SuperTrak EX16350 (16x SATA300 RAID, 128MB PCI-e x8) for my new PC, and I also mentioned the lack of a battery (or even the option to purchase one - that I could find). A simple solution is a UPS - Uninterruptible Power Supply. In simple terms, it’s a battery between your electric net and your device (in this case a PC and monitor). The autonomy is typically short - 10~60 minutes for your average consumer product - but then that’s all you’ll need really. It’s not meant as a device to allow you to game through a 3 day power outtage, just prevent you from losing data, allow you to shutdown your OS and - if you’re lucky (and/or have a more expensive UPS) - even allow you to finish what you were working on.

So why is a UPS better than a RAID controller battery? There is one potential benefit that I can’t be certain of: if the battery only powers the cache and not the hard drives (so whatever’s waiting to be written away stays ‘alive’ in the cache until the PC boots up again and is then written to the drives), you could run out of battery power before power is restored. A definite benefit is that a UPS always allows you to shut down your PC, you could even finish a few things. A UPS can often be used for other devices, or at the least a different PC. Finally a UPS will never be irreplacable because it’s out of production or some such.

Just remember a few things when ordering your UPS:

• If you have a 500W PSU (Power Supply Unit), and it’s showing only 300W draw, keep in mind that current PSU’s have roughly 80% efficiency, so your 300W draw would need at least a 375W UPS
• Always keep a margin of safety - wattage-wise - over your actual usage (I’d recommend 20% above your peak usage)
• Cheaper UPS run off the net and only switch on the battery after the net current has gone. The best UPS supply power from the battery as they constantly recharge it - but keep in mind these types are more expensive and wear out a lot sooner (due to constant use of the battery)
• Last but not least VA (Volt Ampere) is not the same as W (Watt). My Trust UPS PW-4130M 1300VA for example has 1300VA but only supplies 600W (my PSU is rated 560W). Don’t forget to check out the wattage before ordering yours!

This entry was posted on Friday, December 5th, 2008 at 8:12 pm and is filed under Hardware. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.