Page 4 - Minor Tests and Conclusion
Power supplies are interesting products, because often, reviews of products in this category are conducted and tested in methods that make it difficult to distinguish one power supply from another. Many aspects must be taken into consideration. Certain criteria consist of efficiency, noise, power ripples, and of course the ability to pull out the rated specifications. Because many cannot afford such equipment to obtain results regarding those aspects, articles covering power supplies often come out with less than adequate and acceptable information. As this is a product report -- not a review -- what we are doing is a close examination of the power supply and the internal hardware and build. But what we can do for you is do some minor testing with the results we can present to you with and let other review sites with professional equipment show you the actual test results. We are not going to try to create useless test results by installing the power supply into the latest gaming rig and try to take readings from that, as this is not even remotely the correct way to test power supply units. We understand that many websites do that as a means of load testing, but the results, even if you use an oscilloscope and multimeter at each output location, are not sufficient, nor does it accurately reflect the performance of the power supply.
Using our power supply tester which exerts minimal load on the power supply, the initial consumption was 14W as measured by our wall meter unit, indicating the basic load-free power consumption of the power supply was higher than usual. The specific performance of the Thermaltake Smart BM3 850W is yet to be tested by independent sources with professional load testing equipment at the time of review. This is an 80 Plus Bronze certified power supply.
Voltages with minimal load are accurate, which is a basic requirement of power supplies out of the box. The ATX design specifications state a PSU's PG is required to be between 100ms and 500ms, with 250ms maximum for Non-Alternative Sleep Mode and 150ms for Alternative Sleep Mode. This power supply is ATX 3.0 compliant and officially supports Alternative Sleep Mode with 100 to 150ms PG specifications. The tested result was 110ms per my power supply tester, which is within specifications.
Active power correction is important to correct AC load line loss. In AC power, there are three components to it, as there is a phase difference between current and voltage. This makes up the power triangle, which consists of the following: Average usable power, or active power (P, measured in watts), reactive power (Q, denoted as VAR), and total apparent power (S, written as VA). While they all have the same physical units, it is not the same thing. Reactive power actually plays an important role in large power systems for keeping the voltage stable. If there is an insufficient amount of reactive power being injected into an electrical bus, the voltage will become unstable and unable to supply active power to the desired loads. At the distribution level though, reactive power is essentially wasted power, since it does not do any work. Thus, what we want in the case of our power supply unit is active power with as little reactive power as possible. The total power provided over the AC line is the magnitude of the two combined (sqrt(P^2+Q^2)). Power factor is easily calculated by P divided by S. The ideal value is 1.00, and this is where active PFC comes in. The Thermaltake Smart BM3 850W has an APFC circuit, and the power factor should approach 0.99 under a nominal load.
The Thermaltake Smart BM3 850W is a moderately quiet power supply. Under regular loads up to 20%, the Thermaltake Smart BM3 850W is low noise. Personally, I found the fan to be pretty good, even when it ramps up. On a scale from 0 to 10 where 0 is silent and 10 is EDC, I would rate the Thermaltake Smart BM3 850W at 2.0/10 acoustically under nominal loads, because the fan spins really slowly. This does not account for the Smart Zero Fan mode, which has the fan not running at all. I tested the PSU on Smart Zero Fan mode as well, and as expected, the noise level was 0/10 under 20% load, as the fan did not spin.
Thermaltake provided this product to APH Networks for the purpose of evaluation.
The Thermaltake Smart BM3 850W is a budget semi-modular power supply unit with 80 Plus Gold certification compliant to ATX 3.0 and PCIe 5.0 specifications. At 14cm depth, it is the same as the budget, but 80 Plus Gold certified and fully modular SilverStone DA850R Gold 850W. Opening this power supply reveals a selection of Japanese brand capacitors on the primary and secondary side, which is more than what the company promised on the website. However, everything else we can find are Chinese-sourced components, and its detailed performance has not been verified by independent sources. The 5-year warranty is a good number that is consistent with other budget power supplies today. The Thermaltake Smart BM3 850W can be found for under $90 at press time, which is a very good price if you are looking for a strictly budget PSU.
Page Index
1. Introduction, Packaging, Specifications
2. Physical Look - Outside
3. Physical Look - Inside
4. Minor Tests and Conclusion
