Micronics Caslon II 600W PSU Review: A Low-Cost Gem?
Why you can trust Tom's Hardware
EMC Pre-Compliance Testing
EMC, EMI & EMS Acronyms
Electromagnetic Compatibility (EMC): The ability of a device to operate properly in its environment without disrupting the operation of other close-by devices.
Electromagnetic Interference (EMI): This represents the electromagnetic energy a device emits, which can cause problems in other close-by devices if it is too high.
Electromagnetic Immunity (EMS): Tolerance to electromagnetic emissions.
Equipment & Standards
To properly measure the EMI that a device emits, you need special equipment defined by the CISPR 16-1-1 specification. To learn more about our EMI testing equipment, please check out How We Test Power Supply Units.
In order to minimize EMI noise, some standards have been established. The corresponding standards for Information Technology products are CISPR 32 and its derivative EN 55032. In the EU, every product featuring the "CE" marking has to comply with EN 55032. Both CISPR 32 and EN 55032 divide devices into two classes, A and B. B-class equipment is for domestic environments, so its allowed EMI emissions are significantly lower than for A-class devices.
CISPR 32 / EN55032 Limits | ||
---|---|---|
CISRP 32/ EN 55032 Class A Conducted EMI Limit | ||
Frequency of Emission (MHz) | Conducted Limit (dBuV) | |
Quasi-peak | Average | |
0.15 - 0.50 | 79 | 66 |
0.50 - 30.0 | 73 | 60 |
CISPR 32/ EN 55032 Class B Conducted EMI Limit | ||
Frequency of Emission (MHz) | Conducted Limit (dBuV) | |
Quasi-peak | Average | |
0.15 - 0.50 | 66 - 56 | 56 - 46 |
0.50 - 5.00 | 56 | 46 |
5.00 - 30.00 | 60 | 50 |
EMI Results - Average Detector
There are lots of spurs in this test, and the PSU fails to stay within the limits.
EMI Results - Peak Detector
It's rare to see a PSU fail the peak detector tests.
MORE: Best Power Supplies
MORE: How We Test Power Supplies
MORE: All Power Supply Content
Current page: EMC Pre-Compliance Testing
Prev Page Ripple Measurements Next Page Performance, Value, Noise & EfficiencyStay On the Cutting Edge: Get the Tom's Hardware Newsletter
Get Tom's Hardware's best news and in-depth reviews, straight to your inbox.
Aris Mpitziopoulos is a contributing editor at Tom's Hardware, covering PSUs.

RTX 5090D tested with nine-years-old Xeon CPU that cost $7 — it does surprisingly well in some games, if you enable MFG

Threadripper 7000 is the most reliable CPU as per Puget Systems stats — Nvidia RTX Ada Generation GPUs have the lowest failure rates

Intel Panther Lake and Wildcat Lake CPU specs break cover — leak suggests up to 16 CPU cores and 180 total AI TOPS
-
nobspls Why would anyone choose this one say over the Corsair CX650M? Which you can get typically for $50.Reply -
spentshells " Not only does this minimize your carbon footprint"Reply
The idea of conserving electricity is a fallacy, if you use less the people selling can sell more to someone else..... they aren't just holding on to the energy you saved because you're a hero saving the world.
Making your footprint smaller doesn't matter in the least when someone else's foot print just gets that much bigger.
Save some money, sure but for how long? The less you use the more they can charge for that smaller amount later on..... that's how it is.
On a different note, Ill likely try the psu out at one point on a build for someone else. -
rohs42 > The idea of conserving electricity is a fallacyReply
No it isn't. Of course a 100 megawatt generator will not be turned off if someone saves 10 watts of power. But if a 10 million people save 10 watts of power, then of course it will be turned off. And if 100 million people save 10 watts, then there'll be no business case for that new gigawatt power plant.
As citizens, consumers and voters we all bear a small share of responsibility for the state of the world, and we all have a small part to play in making it better. It's only through working together that humanity improves. Your appeal to helplessness and apathy is pathetic. -
jabliese Hey Tom's,Reply
Once upon a time, we had an extensive brown out at work, which went on for 3 days. On day 2, I was surprised to find many of the PC's that were still working were on 60v power. Over the years, it did not seem to have a adverse affect on any of the power supplies. Lately, I have been wondering what their efficiency numbers looked like during that time, any chance you could add a severe undervolt test to the power supply suite? -
Aris_Mp 60V is too low. Most PSUs won't even work at such low voltage. I am surprised to hear that the PSUs at your work were working under such conditions for days.Reply
Efficiency drops along with voltage input. I want to add more protection tests, however I already have enough fails with the current ones. Nonetheless, I am keeping every suggestion under consideration.