be quiet! Power Zone 850W CM Power Supply Review
by E. Fylladitakis on August 14, 2014 6:00 AM EST- Posted in
- Cases/Cooling/PSUs
- PSUs
- be quiet!
- FSP
- Fortron/Source
Hot Test Results
From the tables below, you can see that the output power quality of the be quiet! Power Zone 850W CM PSU is mediocre. The maximum voltage ripple that our instrumentation recorded was 64 mV under maximum load, which is about half of the 120 mV design guide limit but not impressive for a high-performance product. With the unit heavily cross-loaded, the maximum ripple increases even further, up to 78 mV. Voltage regulation is at 2.4% on the major 12V line and a little lower on the minor 3.3V/5V lines, which is good but not unusual for a high performance power supply.
| Main Output | ||||||||
| Load (Watts) | 172.41 W | 429.67 W | 633.45 W | 842.16 W | ||||
| Load (Percent) | 20.28% | 50.55% | 74.52% | 99.08% | ||||
| Line | Amperes | Volts | Amperes | Volts | Amperes | Volts | Amperes | Volts |
| 3.3V | 4.06 | 3.39 | 10.14 | 3.39 | 15.21 | 3.36 | 20.29 | 3.33 |
| 5V | 4.06 | 5.08 | 10.14 | 5.05 | 15.21 | 5.00 | 20.29 | 4.97 |
| 12V | 11.36 | 12.15 | 28.40 | 12.11 | 42.60 | 11.89 | 56.80 | 11.86 |
| Line |
Regulation (20% to 100% load) |
Voltage Ripple (mV) | |||||
| 20% Load | 50% Load | 75% Load | 100% Load |
CL1 12V |
CL2 3.3V + 5V |
||
| 3.3V | 1.9% | 12 | 18 | 24 | 30 | 10 | 34 |
| 5V | 2.2% | 10 | 16 | 26 | 30 | 14 | 38 |
| 12V | 2.4% | 24 | 34 | 48 | 64 | 78 | 30 |
High ambient temperatures have a major impact on the energy conversion efficiency of the be quiet! Power Zone 850W CM, reducing the average nominal load (20-100%) efficiency down to 85.1 % and the maximum efficiency of the PSU to 87%. A >4% efficiency drop is very high for a premium product and is most likely caused by the high resistance of the active components (transistors) that this unit uses. The high resistance increases their thermal losses and temperature, the higher temperature increases their resistance even further, and the effect starts to cascade. Nevertheless, even though the efficiency drops quite a bit, the Power Zone 850W CM still meets the 80 Plus Bronze certification while running in a 50C environment (which isn't actually part of the 80 Plus requirements).
The cooling system of the Power Zone 850W CM displays similar cooling behavior as before once placed inside our hot box. The magnitude of the numbers changes, as the unit is obviously hotter and thus runs louder. The temperature of the unit reaches uncomfortable levels when it operates under maximum load for extended periods under such conditions, but the Power Zone 850W CM did work like a charm and we didn't encounter any issues...except for the noise levels.
As you would expect, what was already a somewhat noisy PSU becomes even more so in our hot box. The Power Zone 850W CM will be audible at virtually any load inside a hot environment, which is not exactly what be quiet!'s company scope describes. Again, we've seen better results from the competition, and what's more they have products that cost less than the Power Zone 850W.
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blackmagnum - Thursday, August 14, 2014 - link
Bean-counters ruining geeks' work once more.StrangerGuy - Thursday, August 14, 2014 - link
Compared to a Seasonic OEMs this is pretty rubbish in comparison, let alone the better Superflower OEM designs.Samus - Thursday, August 14, 2014 - link
Seriously...50db?My 8 year old PC Power Cooling 750 Quad uses an ancient design with an 80mm fan and I don't think the fan has ever exceeded 1500RPM (~36db) so anything modern should exceed this, especially for $160. As said, Seasonic, Superflower, and one of my favorite budget PSU OEM's, FSP, are all considerably better options at this price.
Fortron (Sparkle) are pretty good PSU's but I wouldn't spend more than $40 on one as a low-watt office PC replacement.
Tunnah - Thursday, August 14, 2014 - link
My thoughts too. I have a 3-4 year old Silverstone that cost £80 (I guess about $130 back then), 650w and used for SLI, and you barely hear a peep out of itDanNeely - Thursday, August 14, 2014 - link
Have you ever actually had your PSU at >90% load? Comparing your PSU at a load significantly below max to a second one at full load isn't a fair comparison.What does surprise me is that the fan speed curve on this one appears to be linear. The last time I was shopping for PSUs (a few years ago); most of the ones I saw that showed a fan curve kept the fan at it's minimum speed (or completely off?) for the bottom part of the load curve and only started ramping the speed when it got within 250-300W of max power, mostly relying on passive cooling below that point. I've used that observation for sizing PSUs to a target size of MaxLoad+250W so the fan never spins up adding to system noise.
Streetwind - Thursday, August 14, 2014 - link
As a gamer who assembles their own systems, I make a conscious effort to never buy any component that's explicitly marketed "for gamers" - with the sole exception being the graphics card, of course.This review just underlines once again why that practice is a good practice. Here we have a gamer-targeted product that's too highly powered for the average modern gamer PC, offers only mediocre efficiency and performance, errs on the side of unnecessarily hefty cooling and mounts an unreasonable price tag... and the biggest selling point is a different looking outer shell.
My own PSU is from be quiet!, too. But it's not from this gamer-targeted Power Zone series. No, I chose a Straight Power E9 series part with a wattage rating suitable for a single-GPU system. It is practically inaudible even under load, is rated 80PLUS Gold, was tested for excellent voltage regulation and, get this... cost only half the price of the unit tested in this review.
Seriously, people. Stay away from "for gamer" products. Especially if you're a gamer.
romrunning - Thursday, August 14, 2014 - link
There are far too many reviews for these high-powered PSUs when most people are only running a single GPU. Too many neophyte gamers think they need 750W+ when most can easily get by on 400-550W.We really need more reviews showing the practical power needs of a typical gaming system, and then focus on the PSUs to power them. Just because lower-output PSUs are lower in price doesn't mean we should spend an inordinate amount of time reviewing the higher-powered ones with the higher price tags. Sadly, the "quality" that may or may not be in a mfg's higher-powered PSU doesn't always trickle down to their lower-output models, so it would be good to highlight the ones that are or aren't quality choices at the lower to mid-range.
lmcd - Thursday, August 14, 2014 - link
Do I qualify if I also have a i7-3960X? Probably. But if I'm re-encoding and streaming video in the background while I play a visually-intensive game, I'd rather not have my power supply be the bottleneck. 140 W from my video card and 200 W from my CPU don't really add up to 750W.But maybe I want another card? Especially with AMD CPU buyers, that scenario is common: a desire for upgradeability encourages the $30 for a higher-wattage power supply, as opposed to paying $50 for the 500W then another $80 for the 750W.
Sidenote: given how low the power consumption of Intel CPUs has gotten I'm surprised more manufacturers haven't considered supporting 4x 6pin or even 2x 6pin + 2x 8pin configurations on 550W and 60W PSUs. Connector count, in many cases, can drive the new system builder to the higher-wattage power supplies.
DanNeely - Thursday, August 14, 2014 - link
I think they tend to err on the side of caution since they'd take the blame if someone did overload one; and they can't assume people will only use them with cards that barely need a 6+6 or barely need a 6+8 configuration.4x 6 pin at 600W might be OK, since that'd be 2x 225W GPUs + 100W CPU/mobo + 50W drives/fans/etc = 600W total; but 4x6 GPU power connectors on a 550W PSU could go over the limit easily enough. 2x6 and 2x8 would on 600W would be even worse since that's promising enough power to run a pair of 300W GPUs.
inighthawki - Thursday, August 14, 2014 - link
A good 750W PSU is good enough for even a dual SLI 780Ti system. At 550W, even a demanding single GPU system should have more than an adequate supply of power.However in practice, some people buy these larger PSUs for two reasons:
1) Possibility of future expansion. When I bought my PC last summer, I purchased a larger wattage PSU because I was still debating whether or not to get a second PSU. I haven't yet, but if I decide to, I already have enough power.
2) PSUs generally get their best efficiency while running at 50-60% load. So having a 750W PSU to power a 400W system provides the best efficiency. (Granted I realize for many this is a silly point, since the extra cost of the PSU itself generally will outweigh any cost savings, but maybe they like to be green, or just have the money)