The SilverStone HELA 1200R is a high-performance ATX v3.0 and PCIe 5.0 ready PSU, suitable for power-hungry systems. It is not affordable, but if you pay more than 2,000 dollars for an RTX 4090, you should not cheap out on the PSU that will power it, along with the rest system components.
SilverStone is among the most ethical brands I had the pleasure of cooperating with in my long career as a reviewer. These guys don’t hold grudges if you post a not-flattering review but focus on improving the product under test. This is why SilverStone has a solid name in the market. Moreover, SilverStone uses the version system in its products, so you can know if you got the upgraded model or the previous one, which almost all brands avoid since it makes it difficult to sell existing stock. Finally, SilverStone was among the first to adopt the Cybenetics ratings fully, showing that they don’t have a problem sending their products to a certification agency that will rigorously test them and provide a public report.
The HELA 1200R has super-compact dimensions for a 1200W unit, measuring only 150mm in length. SilverStone loves high-power-density PSUs, so it doesn’t surprise me that they chose a compact platform. CWT’s CSZ platform might be small in dimensions, but it provides high performance and has been proven highly reliable. This is why several popular brands use it. The first it comes to mind is Thermaltake in the GF3 units with 1200W and lower capacities. Moreover, another notable aspect of the HELA 1200R is the ATX v3.0 and PCIe 5.0 compatibility.
Cybenetics Report
- Manufacturer (OEM): CWT
- Max Power: 1200W
- Cybenetics Efficiency: [115V] Platinum (89-91%)
- Noise: Cybenetics Standard (40-45 dB[A])
- Compliance: ATX12V v3.0, EPS 2.92
- Alternative Low Power Mode support: Yes
- Power 12V: 1200W
- Power 5V + 3.3v: 120W
- Power 5VSB: 15W
- Cooling: 135mm Fluid Dynamic Bearing Fan (HA13525H12SF-Z)
- Semi-Passive Operation: Yes (Selectable)
- Modular Design: Yes (Fully)
- High Power Connectors: 2x EPS (2x cables), 6x PCIe 6+2 pin (3x cables), 1x PCIe 12+4 pin
- Peripheral Connectors: 12x SATA (3x cables), 3x 4-pin Molex (single cable)
- ATX/EPS Cable Length: 600/750mm
- Distance between SATA/4-pin Molex connectors: 150mm
- In-cable capacitors: No
- Dimensions (W x H x D): 150 mm x 85 mm x 150 mm
- Weight: 1.75 kg (3.86 lb)
- Warranty: 5 years
Box & Bundle
The box is big and heavy, and most importantly, it provides adequate protection. At its face is a photo of the PSU, the model description, a photo of the 12VHPWR connector, and a PCIe 5.0 badge. Finally, you will find the Cybenetics efficiency badge and not an 80 PLUS one since SilverStone doesn’t do the latter anymore.
Product Photos
The PSU is compact. If you don’t look at the power specs label, you might think this is a 750W or 850W unit. Moreover, the fan grille has large enough perforations allowing for good airflow. Looking at the top side, you immediately see that the 135mm fan is the largest compatible with the small chassis, but it is enough to cope with the thermal loads. With the proper speed profile, it can even offer a silent operation.
Cables
| Modular Cables | ||||
| Description | Cable Count | Connector Count (Total) | Gauge | In Cable Capacitors |
|---|---|---|---|---|
| ATX connector 20+4 pin (600mm) | 1 | 1 | 16AWG | No |
| 4+4 pin EPS12V (750mm) | 2 | 2 | 16AWG | No |
| 6+2 pin PCIe (600mm+150mm) | 3 | 6 | 16-18AWG | No |
| 12+4 pin PCIe (590mm) (600W) | 1 | 1 | 16-24AWG | No |
| SATA (590mm+150mm+150mm+150mm) | 3 | 12 | 18AWG | No |
| 4-pin Molex (600mm+150mm+150mm) | 1 | 3 | 18AWG | No |
All cables are long enough and lack in-cable caps, which is good. The number of connectors is sufficient, including a 600W 12VHPWR, which can fully support an NVIDIA RTX 4090. Lastly, the distance between the peripheral connectors is adequate at 150mm.
Protection Features
| OCP (Cold @ 23°C) | 12V: 118.6A (118.6%), 11.993V 5V: 30.9A (140.45%), 5.011V 3.3V: 30.6A (139.09%), 3.270V 5VSB: 4.8A (160%), 4.959V |
| OCP (Hot @ 40°C) | 12V: 118.8A (118.8%), 12.026V 5V: 30.9A (140.45%), 5.012V 3.3V: 30.5A (138.64%), 3.270V 5VSB: 4.8A (160%), 4.965V |
| OPP (Cold @ 26°C) | 1418.99W (118.25%) |
| OPP (Hot @ 42°C) | 1418.96W (118.25%) |
| OTP | ✓ (150°C @ 12V Heat Sink) |
| SCP | 12V to Earth: ✓ 5V to Earth: ✓ 3.3V to Earth: ✓ 5VSB to Earth: ✓ -12V to Earth: ✓ |
| PWR_OK | Accurate but lower than 16ms |
| NLO | ✓ |
| SIP | Surge: MOV Inrush: NTC Thermistor & Bypass relay |
OCP at 12V and OPP are correctly set. On the other hand, OCP on the minor rails is set sky-high, which is the case in most PSUs I have reviewed so far (and I have reviewed hundreds). There is no need for such high amperage on the minor rails, especially the 3.3V one. Lastly, there is over temperature protection (OTP), which is crucial to any PSU.
Part Analysis
| General Data | |
| Manufacturer (OEM) | CWT |
| Platform | CSZ 1200W rev. D04 |
| PCB Type | Double-Sided |
| Primary Side | |
| Transient Filter | 4x Y caps, 2x X caps, 2x CM chokes, 1x MOV |
| Inrush Protection | 1x NTC Thermistor SCK-207R0 (7 Ohm) & Relay |
| Bridge Rectifier(s) |
2x Vishay LVB2560 (600V, 25A @ 105°C)
|
| APFC MOSFETs |
3x Infineon IPA60R099P6 (600V, 24A @ 100°C, Rds(on): 0.099Ohm) & |
| APFC Boost Diode |
1x On Semiconductor FFSP1665A (650V, 16A @ 135°C)
|
| Bulk Cap(s) |
1x Nippon Chemi-Con (420V, 820uF, 2,000h @ 105°C, KHE)
|
| Main Switchers |
2x Infineon IPA60R099P6 (600V, 24A @ 100°C, Rds(on): 0.099Ohm)
|
| APFC Controller |
Champion CM6500UNX
|
| Resonant Controller | Champion CU6901VAC |
| Topology |
Primary side: APFC, Half-Bridge & LLC converter
Secondary side: Synchronous Rectification & DC-DC converters |
| Secondary Side | |
| +12V MOSFETs | 8x Infineon BSC014N06NS (60V, 152A @ 100°C, Rds(on): 1.45mOhm) |
| 5V & 3.3V | DC-DC Converters: 2x UBIQ QN3107M6N (30V, 70A @ 100°C, Rds(on): 2.6mOhm) & 2x UBIQ QM3054M6 (30V, 61A @ 100°C, Rds(on): 4.8mOhm) PWM Controller(s): uPI-Semi uP3861P |
| Filtering Capacitors | Electrolytic: 2x Nippon Chemi-Con (105°C, W), 1x Nichicon (2-5,000h @ 105°C, HD), 3x Nichicon (4-10,000h @ 105°C, HE), 1x Nichicon (5-6,000h @ 105°C, HV), 1x Nippon Chemi-Con (4-10,000h @ 105°C, KYA) Polymer: 21x FPCAP, 7x NIC |
| Supervisor IC | Weltrend WT7502R |
| Fan Controller | Microchip PIC16F1503 |
| Fan Model | Hong Hua HA13525H12SF-Z (135mm, 12V, 0.5A, Fluid Dynamic Bearing Fan) |
| 5VSB Circuit | |
| Rectifier |
1x PS1045L SBR (45V, 10A)
|
| Standby PWM Controller | On-Bright OB2365T |
Channel Well Technology (CWT) is the OEM of the HELA 1200R, and the platform that SilverStone used is called CSZ. The CSZ1200V-G rev. E02 can be found in the Thermaltake GF3 1200W, which I have already reviewed, while SilverStone uses the rev. D04 of the CSZ platform. The differences between these two revisions are minor, with the most distinct being the slightly larger dimensions of the rev. E02 allows for a pair of bulk caps, while the older revision only takes a single bulk cap.
On the primary side, we find an APFC converter, a half-bridge topology, and an LLC resonant converter for increased efficiency. Typically, for a high-end unit, the secondary side employs synchronous rectification for the 12V rail and a pair of DC-DC converters for the minor ones. Japanese brands provide all caps and are of high quality. The only problem here is the low capacity of the bulk cap, which won’t allow for more than 17ms hold-up time, which is the minimum that the ATX spec requires. There wasn’t space for a larger cap in this PCB, so TT used the modified CSZ platform to install two parallel bulk caps. Lastly, the soldering quality is high, and the Hong Hua fan is reliable and will easily outlive the five-year warranty. Thermaltake uses the same fan in the GF3 1200, which is covered by a ten-year warranty.
Load Regulation
Load regulation is within 1% on all major rails, so everything is fine.
Ripple Suppression
Ripple suppression is exceptional!
Transient Response
Transient response with normal loads is decent. The 12V chart might not look flattering, but the deviation is not far away from 1%, which I consider a good level.
Transient Response ATX v3.0 & 12VHPWR Connector Tests
The 12V rail performs well in the super-tough ATX v3.0 tests, with the weak link being the 3.3V rail, which is very close to the lowest allowed threshold during the 10 kHz transient response test.
Hold Up Time
The hold-up time cannot reach 17ms. Given the low capacity of the bulk cap, I expected even worse results here, but thankfully, this wasn’t the case. The power ok signal is accurate, but its hold-up time is notably below 16ms, which the ATX spec requires.
Timings
The PSU supports Alternative Low Power Modes.
Inrush Current
Inrush current is low at 115V and could be lower at 230V.
Efficiency Normal, Light & Super-Light Loads
Efficiency with normal loads is not competitive, but the situation turns with light loads where the CSZ platform destroys the competition.
Average Efficiency 5VSB
The 5VSB rail has decent efficiency.
Vampire Power
Vampire power is low!
Average Efficiency
The average efficiency needs a slight boost to get further away from 89% with 115V and 91% with 230V.
Average PF
The APFC converter performs well, especially with 230V.
Average Noise
The fan speed profile is aggressive, so this PSU is unsuitable for systems where quiet operation is the first priority. The GF3 1200W, which uses the newest CSZ platform, has similar noise output in both cases.
Fan Noise & Speed Maps @ 28-32 °C
The semi-passive operation doesn’t last long if you push hard the minor rails. This is because the VRMs on the secondary side don’t use any heatsinks, so active cooling is required at high loads. With close to a 600W load, the PSU is silent, and it takes more than 750W to exceed the 30 dBA mark. Things get serious with more than 900W, where the fan’s noise exceeds 40 dBA, and the party begins with 1050W and more, where noise goes over 45 dBA. The super-compact dimensions do not allow for optimal airflow. This is the most crucial con of high-power-density PSUs.
Overall Performance
The overall performance is high. The GF3 1200W, which uses a newer version of the same platform, leads the race.
Epilogue
SilverStone did well teaming with Channel Well Technology for the HELA 1200R unit. Overall performance is high, and the PSU is fully ATX v3.0 and PCIe 5.0 compatible, according to my tests. The compact dimensions make it look like an 850W PSU but do not let them fool you. It can deliver up to 2400W for ultra-short periods to cope with power spikes. Speaking of power spikes, so far, I didn’t manage to catch any serious ones in every modern GPU I tried, so I wonder why the PCIe 5.0 and the Intel ATX v3.0 specs demand so many in this regard unless the people behind the specs mentioned above know something that I don’t. In other words, they expect the future GPUs to have even higher power requirements. This remains to be seen, and thanks to Powenetics, I can have the complete picture of power requirements and not only.
The primary opponent for the HELA 1200R is the Thermaltake GF3 1200W, which has slightly larger dimensions, about the same noise output, and achieves about 2% higher overall performance. The latter also has double the warranty, but I mentioned before that so long warranty periods in PSUs look unrealistic. You won’t see such long warranty periods even in cars, so it seems crazy to me to have a PSU with a more extended warranty than my bullet-proof Toyota car!
The SilverStone HELA 1200R is a good choice if you need a strong PSU for your high-end NVIDIA card, requiring a 12VHPWR connector. This doesn’t mean you cannot use it with AMD’s high-end GPUs since it also has enough 6+2 pin PCIe connectors. At light and moderate loads, it offers a quiet operation, but the more you load it, the more you will have to dial up the volume of your speakers. You should not expect a high-power density PSU to be whisper-quiet at high loads.
Buy SilverStone HELA 1200R Platinum
Buy Thermaltake Toughpower GF3 1200W
Buy Corsair HX1500i
Buy Cooler Master MWE Gold 1250 V2
Buy be quiet! Dark Power Pro 12 1200W
- Full power at 47°C
- ATX v3.0 and PCIe 5.0 compatible
- High overall performance
- Top build quality
- Properly set OCP at 12V and OPP
- Quiet operation under light and moderate loads
- Great ripple suppression
- Within 1% load regulation on all major rails
- Highly efficient at light loads
- Low inrush current with 115V
- High-performance APFC converter
- ALPM support
- Lots of connectors, including a single 12VHPWR (600W)
- Fully modular
- Low vampire power
- FDB fan
- Adequate distance between all peripheral connectors
- 5-year warranty
- High OCP on the minor rails
- High inrush current with 230V
- Noisy at high loads
Thanks, waiting for the 1000w gold version.