Seasonic Prime TX-1600 ATX v3.0 PSU Review

General Data
Manufacturer (OEM) Seasonic
PCB Type Double-Sided
Primary Side
Transient Filter 7x Y caps, 3x X caps, 2x CM chokes, 1x MOV
Inrush Protection 2x NTC Thermistor MF72-20D20M (20 Ohm) & Relay
Rectifier FETs
4x IPB60R040C7, 1x LL25XB60 25A 600V
APFC MOSFETs
4x Infineon IPA60R099P6 (600V, 24A @ 100ยฐC, Rds(on): 0.099Ohm)
APFC Boost Diode
2x Cree C6D10065A (650V, 10A @ 155ยฐC)
Bulk Cap(s)
3x Nippon Chemi-Con (420V, 820uF each or 2460uF combined, 2,000h @ 105ยฐC, KHE)
Main Switchers
4x Infineon IPA60R080P7 (600V, 23A @ 100ยฐC, Rds(on): 0.08Ohm)
Drivers IC 2x Silicon Labs Si8233BD
APFC Controller Texas Instruments UCD28070
Resonant Controller Champion CM6901T2X
Topology
Primary side: Bridgeless, Interleaved PFC, Full-Bridge & LLC converter
Secondary side: Synchronous Rectification & DC-DC converters
Secondary Side
+12V MOSFETs 16x Nexperia PSMN1R0-40YLD (40V, 198A @ 100ยฐC, Rds(on): 1.93mOhm)
5V & 3.3V DC-DC Converters
Filtering Capacitors Electrolytic: 6x Nippon Chemi-Con (105ยฐC, W), 1x Nippon Chemi-Con (5-6,000h @ 105ยฐC, KZH), 1x Nippon
Chemi-Con (2-5,000h @ 105ยฐC, KZE), 3x Rubycon (6-10,000h @ 105ยฐC, ZLH), 1x Rubycon (3-6,000h @ 105ยฐC, YXG)
Polymer: 12x Nippon Chemi-Con, 22x FPCAP, 4x
Supervisor IC Weltrend WT7527RA (OCP, OVP, UVP, SCP, PG)
Fan Controller Nuvoton M031
Fan Model Hong Hua HA13525H12SF-Z (135mm, 12V, 0.5A, Fluid Dynamic Bearing Fan)
5VSB Circuit
Rectifier
1x Infineon BSC100N06LS3 FET (60V, 36A @ 100ยฐC, Rds(on): 10mOhm)
Standby PWM Controller Power Integrations INN3164C

Despite the huge PCB, the platform is densely populated. Moreover, I usually don’t find large heatsinks in modern PSUs. Although Titanium efficiency allows for low thermal loads, Seasonic used large heatsinks to make the fan’s noise as low as possible. A bridgeless, interleaved PFC is used to achieve high efficiency, along with a full-bridge topology and an LLC resonant converter. Seasonic still needs to jump onto the totem-pole PFC because it is a more complex implementation. If you are careless, it can have reliability issues, especially at low-voltage inputs. So far, only Flextronics with the Corsair AX1600i managed to build a reliable totem-pole platform. Flextronics has vast experience in digitally controlled PSUs, so it correctly tuned the totem-pole PFC converter of Corsair’s high-end PSU. Seasonic prefers to stick to analog solutions for its PSUs, draining every bit of performance out of them.

The 12V rail is generated through 16x powerful Nexperia FETs. The same rail also feeds a pair of DC-DC converters, which generate the minor rails. It is easier to identify all parts on this platform by fully desoldering it, which I didn’t want to do since I need it to remain fully operational for future testing.

The build quality is top, and the same goes for the soldering quality. Seasonic used Japanese caps everywhere, both electrolytic and polymer, and the bulk caps have a vast combined capacity, close to 2500uF! Because of the large bulk caps and their combined capacity, not one but two NTC thermistors had to be used, with 20 Ohm resistance each! Despite the large PCB, space is still an issue, so both are installed onto a vertical board.

Seasonic pushed as far as possible analog-controlled PSUs, and it is high time to start designing digital platforms, which should prevail at some point, or else we will be stuck at Titanium efficiency as the highest available. There is a Diamond level in the Cybenetics scheme, and there is not a single entry for quite some time now, and this has to change at some point!

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18 thoughts on “Seasonic Prime TX-1600 ATX v3.0 PSU Review

  1. Perhaps it would be useful to include a dummy result on each chart representing the next Cybenetics efficiency rating up from what Cybenetics rate the reviewed PSU at (and also the minimum spec for the actual rating of the PSU).

    For example:

    Average Efficiency
    115V AC Input (Higher is better)

    Silverstone DA1650-G: 89.27%
    Corsair HX1500i: 89.52%
    Thermaltake Toughpower GF3 1650W: 89.76%
    > [Cybenetics Titanium PSU min. spec.]: 91%
    be quiet! Dark Power Pro 12 1500W: 91.04%
    Thermaltake Toughpower TF1 1550W: 91.05%
    EVGA SuperNOVA 1600 T2: 91.35%
    ASUS RoG Thor 1600W: 91.73%
    XPG Fusion 1600W: 91.97%
    Corsair AX1600i: 92.22%
    Seasonic Prime TX-1600 (ATX 3.0): 92.27%
    Wentai Aidan – T616: 92.71%
    > [Hypothetical Cybenetics Diamond PSU]: => 93%

  2. I find it funny that every time it appears that analog PSU tech is dead Seasonic says “hold my beer.” I don’t remember which PSU review it was for on Tomshardware, but you said that to hit ATX 3.0 specs you figured Seasonic would need to go digital. They now have two ATX 3.0 PSUs that are still analog and are some of the best in their class.

    1. They did pretty well yes. Seasonic’s engineers don’t stop to push the analog technology high. Basically I was saying digital not for ATX v3.0, but for totem-pole and efficiency because to achieve even higher than Titanium, you definitely need totem-pole and by that time only through digital you could control such a PFC converter.

  3. Great review. Any information on when this will be available in Europe or US? Can’t seem find it on Seasonics site either.

  4. Excuse my ignorance but i can’t understand one point. How can transient response reach %200 load, when OPP or OCP set to %130?

  5. Hello, this might be a dumb question, but this PSU isn’t available as of now (14th June 2023), is it? I looked all over Seasonic’s website and all I can find is a ATX 2.5 TX-1600 PSU, which is not ATX 3.0 and therefore PCI Gen 5 ready.

      1. There are reddit rumors that some guy contacted them and they informed him about an ATX 3.1 version coming sooner or later so maybe we will never see the ATX 3.0 en masse in the EU.

  6. Saw some conflicting information on the net, so I wanted to ask the expert. Are the 12vhpwr connectors on this PSU capable of outputting the full 600 watts? I know the 12vhpwr cable itself supports 600 watts (melting issues aside), but I saw some forums stating the PSU only outputs 450 from the connectors. For context, I have Gigabyte 4090 Gaming OC which has a power limit of 600 watts, so I want to make sure I pick a PSU that can feed it if I decide to tinker with overclocking. Thanks.

    1. Yes they are. Also please note that according to my measurements, 450W vs 600W on an RTX 4090 doesn’t provide anything significant on performance perspective.

  7. Thanks, super useful stuff. Where did the XPG Fusion 1600 results come from? Have you tested that one as well?

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