UPS for Mac

1. Either will do.

2. A correctly sized UPS for a Mini will not be powerful enough for an iMac, buy one big enough for the iMac from the start.

I have a Cyberpower 1500 and works great. I started out with the simulated sine wave and it appeared to work fine but the next day saw a pure sine wave on sale for about $10.00 more so I returned the first one and got the later. It powers my Mini, and TBD and modem and router for about 30 minutes.

As for your future proofing, I am using a APC Back-UPS ES 750

with the following connected:

Late 2013, 27" iMac 3.2GHz, 32GB RAM

Thunderbolt Display

2 external bus powered portable disks, one 500 GB HDD, one 256 GB SSD

CD/DVD/BD drive

5 port ethernet hub

With these items running off the backup outlets, I get 15-20 minutes of runtime

which is plenty of time to survive short power blips and plenty of time to do a graceful

shutdown should the power outage be longer term.

You're welcome.

Csound1 is wrong. You may get away with it for a while, maybe all the time with luck but the chance of PSU failure with a PWM is always there as I found to my cost with my 2012 iMac. Bought a Cyberpower PSW unit, more costly but I now feel confident that I can use it with an Energy Star compliant PSU as well as Macs (which have them and is why they can be damaged with the wrong UPS).

The reason many will say a PWM UPS will suffice is because they don't actually resort to it as they don't get that many power outages. I get around 4 or 5 a month, but not consistently, so my UPS was called into action several times both while I was present and when I was absent. It was an APC UPS, but I did notice that when the iMac (before it went faulty) would emit a barely there high-pitched whine and the screen contrast seemed to change. Since Apple replaced the PSU and I now use a Cyberpower PSW UPS none of this is apparent and I have happily run with it for a year on an iMac and Mac Mini.

I have posted my report on this on the community as I feel it is important and Apple were unaware or would not admit to it.

By the way I am an electrical engineer so I have done my research and know what I am talking about (shame I wasn't thinking before the first PSU fail).

Welcome to the forum Grem, I too am an electrical engineer (IBEW 134) and I entirely disagree with you, and I note that you have thus far solved no problems at all for anyone.

Readers can draw their own conclusions from that.

It's irrelevant how many answers I have provided thus far, I haven't been on this community much yet that's all. But I have worked in the industry on machines (electrical, electronic, IT) installing and maintaining for 28 years, have every professional qualification, I hold a UK FIET membership etc. etc. But we need to keep this in layman's terms.

Modern computer power supplies are more efficient than ever, and also incorporate something called "active PFC". Active PFC is a good thing, and more and more power supplies are using it, including iMacs.

Active PFC and stepped sine waves do NOT always play well together. If you get a new computer, or a new power supply, it's possible it might not work with your old UPS. If you buy a new UPS, you should make sure it produces a true sine wave output, not only because you're current computer might need that, but because your next computer is even more likely to require it.

There are differences in quality of UPSs and other variances but for the relatively small extra outlay I highly recommend pure sine wave UPSs and stand by that for the OP question.

Welcome to the forum Grem, I too am an electrical engineer (IBEW 134) and I entirely disagree with you, and I note that you have thus far solved no problems at all for anyone.

Apple Macs have historically had far more robust power supplies than the cheap trash in many PCs. Not only can I literally not remember the last time I had a Mac power supply fail on any Mac model but when brown-outs occurred I often saw most if not all the Macs in the office carry on running oblivious to that while many of the PCs shutdown/crashed/rebooted.

All I can say is it happened to my 2012 27" iMac and it was the PSU that had failed and doing some research and using my own knowledge it became apparent that the wrong UPS can sometimes cause a PSU failure. I am sure there is plenty of anecdotal evidence against this but also plenty that have had the same issue but the owner has not realised what the problem was. As I said before, if you understand PFC in PSUs it is proven electrical theory and that is why Pure (or True) Sine-wave UPSs are manufactured in the first place. It's nonsense to say Apple PSUs are more robust, they do not have any inherent difference to the average PFC PSU out there.

A look at the Youtube video linked below gives an idea to anyone mildly interested. This whole issue was raised because it can happen and googling 'pure sine wave UPS' or 'iMac PSU faults' or similar will bear out the potential problems, so in summary, I personally recommend them for computers using PFC PSUs.

https://www.youtube.com/watch?v=6yMNlU9gueU

Changing your story now gremLyn, so now I am wrong sometimes?

A useful link to save me the effort:

https://forums.lenovo.com/t5/ThinkServer-Rack-Mounted/Selecting-the-right-UPS-a- primer-on-UPS-design-and-planning/ta-p/1723567