Redundant PSUs In A Standard ATX Chassis: FSP's Twins Series

FSP's new Twin Series, which includes redundant PSUs suitable for home use and not just for business environments, made its debut today. Initially, only the 500W model will be available, with the 700W unit coming soon, according to FSP. The Twin Series units fit in most ATX compatible chassis and host two identical PSUs. In case one of them fails, the other one immediately takes over, ensuring the system's proper operation.

This type of PSU (redundant) is widely used in server-grade systems were reliability is priority number one. Normally their dimensions are much larger standard ATX PSUs, but FSP managed to squeeze two hot-swappable PSUs into a regular-sized ATX PSU chassis, thereby granting all consumers increased reliability.

In a snap, the product highlights are the following:

  • Fully 500W/700W PS2 Redundant Power Supply with remarkable power density
  • Hot-swappable modular design
  • Digital controlled PSU design
  • 230V 80PLUS® Gold certified with 90% peak efficiency at 50% load
  • Compatible with Regular ATX Cases
  • Complies with both standard ATX 12V and server EPS 12V power supply standards
  • Complete protection: over current, short circuit, over-voltage, and fan failure
  • Reliable, 24-hour operation even at 50°C
  • Low ripple and noise
  • Monitor performance with FSP Guardian software
  • Backed by a 5-year warranty

LineFSP Twins
500W ModelFrame: FSP500-70RGHBB1 Single Module: FSP520-20RGGBB1
700W ModelFrame: FSP700-50RGHBE1 Single Module: FSP720-20RGGBE1
Rated Output Power 500W, 700W
Efficiency80 Plus Gold (230V)
Intel Haswell ReadyYes
Operating temperature0°C ~ 50°C
ProtectionsOver Voltage Protection
Over Current Protection
Short Circuit Protection
Fan Failure Protection
Cooling2x Dual ball bearing fans, 40 mm
Semi-passive operationYes
Number of ConnectorsEPS (4+4 pin): 2
PCI-E (6+2 pin): 2
Molex (Peripheral) : 2
FDD : 1
Dimensions150 mm (W) x 87 mm (H) x 190 mm (D)
ComplianceATX12V v2.4, EPS 2.92
Warranty5 years
MSRPFSP500-70RGHBB1: $399
FSP700-50RGHBE1: $499

FSP stated that the PSUs feature a digital platform, and we're eager to dismantle them and inspect the design in order to find out if they use a fully-digital platform or a hybrid design where analog and digital circuits operate in parallel. In addition, FSP chose to certify the PSU with the 80 PLUS 230V program, where it achieved Gold efficiency. Normally, server units use 230V input, which is why FSP didn't go with a 115V certification.

One key feature these PSUs lack, though, is over temperature protection; however, FSP did include fan failure protection.

Because these are server-grade PSUs, they can operate 24/7 even under 50°C ambient temperatures. In addition, they promise low ripple and noise, something that we'll have to verify with our own equipment. Moreover, because the platform is digital, it offers monitoring functions through the FSP Guardian software. You will have to connect the PSU to a USB header on the system's mainboard in order to establish communication with the software. Through the FSP Guardian, users can monitor input and output wattage and check on the PSU's efficiency along with other metrics, in real time. You can also keep up to seven days of system logs. Both Twin Series members are covered by a five year warranty.

We should mention that besides the monitoring software, which is indeed a highly welcome feature, the PSUs also feature LED indicators that can provide alarms in case something goes wrong with the system. Besides the alarm functionality, those indicators can also help in problem diagnosis. In the event that one of the two embedded PSUs fails, an alarm will sound, and an LED indicator will point out the failed PSU that needs to be replaced.

The 500W model of the Twin Series is available with an MSRP of $399, whereas the 700W unit will cost $499. These prices are definitely stiff, but keep in mind that we are talking about redundant PSUs, not normal ones.

We should also clear up one more issue that will likely matter to many of you: Because both units include a couple of PSUs inside, naturally you will be wondering if both are used at the same time. According to FSP, these two power modules will automatically share the load for optimum efficiency, and if one fails, the other module will immediately take over the whole load. We cannot know exactly how this system works just yet, but we are going to find out soon enough.

FSP500-70RGHBB1 Power Specs
Max. PowerAmps202016161630.5
Total Max. Power (W)500
FSP700-50RGHBE1 Power Specs
Max. PowerAmps202017171730.5
Total Max. Power (W)700
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  • turkey3_scratch
    Can't wait for this review!
  • thundervore

    I am impressed and have to say I am excited about this as we finally see some technology improvements in consumer PSU other than RGB fans. Cant wait to see the titanium variants with 0 RPM 140mm fans.

    I look forward to the review and the release of these.
  • Rhinofart
    I remember seeing something like this a very long time ago. I'm saying close to 10 years. Redundant ATX powersuppy. I never went for one because I needed way more power than they were able to put out at the time.