st85f-p

 

The SilverStone ST85F-P is a 850W PSU in the Strider Plus series. There are many models available in this line, both regular and modular, to fit any type of PC build. Models run from 350W all the way up to 1500W. From past experience, SilverStone PSU’s are high quality, quiet running products. Hopefully the ST85F-P follows this pattern. The model reviewed today is 100% modular. Every cable, including the 20+4 pin main connector can be removed. We were intrigued on initial inspection of the PSU, noticing a strange bulge at the end of the PCI-E cables. SilverStone has added capacitors to these cables to filter out interference and smooth the output to connected graphics cards. Very cool.

The build quality of the ST85F-P is very good. The PSU has some good weight to it, which is usually a sign of high quality. The size is comparatively small for a PSU of this wattage. This factor will allow greater space allowances in a larger number of enclosures. The larger models from other companies will not fit in many cases. Read on to see how the ST85F-P fared in testing.  For full specs, visit the product page at SilverStone’s website.

Packaging and Accessories

The ST85F-P comes in very nice packaging that protects the PSU very well. The ST85F-P comes with the manual, product guide, power plug, velcro straps, wire ties, four black PSU screws and four thumb screws.

st85f-p-1

st85f-p-2



Exterior

The PSU comes shipped with all cables already attached, but we recommend removing them before installing the unit into your case. The cable connectors are keyed to prevent improper installation and are easy to remove and install.  The exterior is a nice matte finish black paint job.

st85f-p-6

st85f-p-3


The ST85F-P uses a single +12V rail at 67A (72A peak). This should be more than enough power for most high end PC’s. There is something very different going on with the PCI Express cable here. SilverStone has added capacitors to the ends of the cables to provide better constant power to your expensive graphics cards. The heat shrink tubing protects the capacitors. Well done SilverStone.

st85f-p-10

st85f-p-9

The rear of the PSU only includes the spot for the wall plug. There is no power switch or voltage selector on this model. The single 135mm fan runs nearly silent at only 19dBA-36dBA. Build quality is high and installation was easier than usual due to the smaller size of a PSU of this power. The PSU was installed with the cables removed, providing a good building experience.

st85f-p-7

st85f-p-8

st85f-p-4

st85f-p-5


Voltage Tests

psu-tolerances

The above image is the power supply voltage tolerances chart. All ATX v2.2 PSU’s should have voltages that fall between these minimum and maximum voltages.*These numbers represent only one PSU and should not speak for the entire line of power supplies. You should always check voltages on a new PSU to make sure they are within accepted ranges.

ST85F-P Voltages

+12V =11.99V

+5V =5.01V

+3.3V = 3.335V


Conclusion

In our testing, the voltages were right on target. The system was put on a 100% CPU load for many hours to test stability of the voltages. The PC was monitored with CPUID Hardware Monitor. Voltages remained almost dead-on with nary a fluctuation to be seen. The SilverStone ST85F-P is a great PSU for a high end PC. It’s really a shame that this PSU doesn’t have a power on/off switch in the back. I find the switch very convenient at times. I hope this isn’t a trend starting. The unit scores very high because of the voltage tests and the silent fan. We also liked the addition of the capacitors on the PCI-E cables. The ST85F-P is quieter than our previous bench PSU (PC Power Silencer 750W) that was recently retired and replaced by SilverStone’s ST60F. The ST60F will continue as our test PSU for Small form factor (SFF) and HTPC cases, but our new high end PSU will be the ST85F-P.