Part Analysis
| General Data | |
| Manufacturer (OEM) | CWT |
| Platform | CSZ |
| 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 WeEn WNB2560M (600V, 25A @ 127°C)
|
| APFC MOSFETs |
3x Infineon IPA60R099P6 (600V, 24A @ 100°C, Rds(on): 0.099Ohm) &
1x SyncPower SPN5003 (for reducing the no-load consumption) |
| APFC Boost Diode |
1x Infineon IDH16G65C6 (650V, 16A @ 135°C)
|
| Bulk Cap(s) |
1x Nippon Chemi-Con (420V, 1150uF, 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 | 10x 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: 3x Nippon Chemi-Con (105°C, W), 1x Nippon Chemi-Con (2-5,000h @ 105°C, KZE), 1x Nichicon (5-6,000h @ 105°C, HV), 2x Nichicon (4-10,000h @ 105°C, HE), 1x Nippon Chemi-Con (4-10,000h @ 105°C, KYA)
Polymer: 16x FPCAP, 7x NIC, 1x Nippon Chemi-Con |
| 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 D10S45L SBR (45V, 10A)
|
| Standby PWM Controller | On-Bright OB2365T |
CWT’s CSZ platform is popular among ATX v3.0-ready PSUs nowadays. Thermaltake’s GF3 members with up to 1200W capacity use the same platform, and Montech also utilizes it for its Titan Gold units. The build quality is high, thanks to the good components and impeccable soldering quality. We find a half-bridge topology and an LLC resonant converter on the primary side. The secondary side employs a synchronous design for rectifying the 12V rail and a pair of DC-DC converters for the minor rails. Given the unit’s capacity, the heatsinks are small and restricted to the primary side. There are no proper heatsinks on the secondary side, so strong active cooling is required to remove heat. All 12V FETs are installed on a vertical board next to the main transformer to save space. The small distance that current travels from the main transformer to 12V FETs minimizes energy losses.
I have NZXT C1200 for about year. From beginning there was loud coil whine that you could hear if PC wasn’t doing anything and it dissapeared if you lauch any program (game, chrome etc). But about 6 months past from purchase coil whine dissapeared now there is no coil whine at any circumstanstances
i just got the same model and having the coil whine issue when there isnt any load and disappears when there is load. just like yours. i hope mine goes away after time, also did it comeback after a while for you ? or still no coil whine
I have a question about the C1200 PSU. I am want to get a custom 12VHPWR cable but cant find one that mentions this PSU. So I’m asking if all pinouts are the same on the 12VHPWR cables and if not what power supply has the same pinout? Thanks for you help on this matter.
As far as I know the pinouts must be the same in 12VHPWR cables, unless the PSU doesn’t use a 12+4 pin header.
Thank you as always. Please keep doing these great reviews.
Best regards
Hi,
I must say these are great reviews.
I am divided which one to go for between NZXT c1200w and Thermatake Toughtpower GF3 1200w. Any recommendations?
The NZXT C1200 has slightly better performance, although it uses the same platform, because of some part changes. If the price difference is small go with NZXT.
Great, thank you for your suggestion.
Overall which 1000w-1200w PSU would you recommend?
Please check on my best ATX v3.0 PSUs article for recommendations. I think it is better to read and check the graphs there.
Hi, I have checked the article. It is absolutely great and informative.
A colleague of mine pushes me more to Be Quiet! Straight Power 11 1000W Platinum instead of NZXT C1200 or C1000.
I will appreciate if you provide your opinion which one should I get between Be Quiet! Straight Power 11 1000w Platinum vs NZXT C1000 Gold?
CPU: Intel i5-13600k, GPU: RTX 3070 Ti, or 4070Ti OC, 3 to 4 M.2 SSD’s, 1 x Fan cooler, Gigabyte ATX Z790 Gaming X AX Motherboard, 2 x 32gb DDR5 Ram (total 64gb), No Sata
Thanks a lot.
I am not sure if I already replied to you but anyway will write this down. The Straight Power 11 1000W is old, and not ATX v3.0 ready. You should get an ATX v3.0 ready PSU, because it is future-proof and will support the current and upcoming GPUs.
Hi there,
any plans to test the NZXT C850 2022 PSU?
Only found a “real” review by eteknix which suggests performance and efficiency are top notch. The 2022 models are all be based on the CWT CSZ platform as opposed to the 2020 model, which was produced by Seasonic, right?
So is it safe to assume that the C850 achieves about the same performance as the C1200 model (although the C1200 is ATX 3.0 whereas the lower power models aren’t)?
If it is CSZ you could look at the Thermaltake GF3 850 or the Montech Titan Gold 850.
Thanks for the suggestions!
What I don’t understand in general (likely because I am a noob when it comes to PSUs):
How can the same platform (e.g. CWT CSZ) be used in ATX 2.5x and ATX 3.0 PSUs? What parts of a PSU are different internally between ATX 2.5x and ATX 3.0 PSUs that are based on the exact same platform, if any? Or is ist just a matter of certification (costs) and the 12VHPWR outlet being present or not?
Owned two in the span of 4 days. Both had coil whine in idle state. One switched off itself after a few hours of use. Had to return it. I’m on the second one now and waiting to see if it has the same defect. Probably will return it also and stay away from NZXT as the coil whine is infuriating. In Europe so 230V here.
Weird, this platform is also in the TT GF3 1200, Montech Titan Gold 1200. I have evaluated 5-6 models and didn’t notice anything weird. You probably had bad luck. Check also the other system parts, because coil whine is because of a combination of parts.
Thank you – You are right! The first one seems to suffer from some defect that made it shut down the pc after a while. The second seems to stable up till now. Thanks to you I discovered it has something to do with the MSI SUPRIM X GeForce RTX 4070 Ti. I removed the PSU and used PSU tester and there was no coil whine.
When I start up the PC with the MSI card there is coil whine coming from the PSU till I boot into windows and turn on my second screen or start a game then it’s gone. It is really coming from the PSU. I honestly don’t know why but my theory is that in combination with the MSI card something is happening at very low loads that is causing this. Honestly very annoying tho as this card is dead silent and I dont want another.
Hello. I faced the same problem. But first I want to say that I really like your site and want to thank you for your work. After reading this article, I finally decided which PSU I want. Before that, the search took several weeks. I barely managed to buy it for a good price of 200 EUR on Amazon.
When I finally assembled the computer, I was very upset. The noise from the coils was terrible. It is interesting that it is present when the system is not under load. For example, while surfing in the browser. Another interesting observation is that if you boot Windows in safe mode – there is no coil whine. Also the whine goes away if you run the motherboard BIOS. Another observation, the noise is only present when the PSU is paired with my new AMD Radeon 6900 XT graphics card. If I put in my old 5700 XT video card the coil whine goes away. I concluded that it had something to do with the AMD driver. If there is a standard Windows driver, everything is fine. As soon as you install the actual driver from AMD, the problem appears. I have tried several drivers from this year and last year, problem exists with all of them. Maybe it’s somehow related to energy saving? I tried to do software undervolt in the driver itself, it did not solve the problem. If I start a game or something else that loads the card, the problem seems to disappear, or I can’t hear it because the fans on the video card are working.
I don’t know what to do. I will no longer be able to change the video card, because I bought it last Christmas and the deadline for returning it to the store has already passed. It was because of the new video card that I was forced to change the PSU. I can still return the PSU to the store, but I’m not sure that will solve my problem, and at this price, I can’t see anything better right now. It probably won’t work to exchange for the same model either, because they are no longer available. Please help, I need advice.
I made a couple of videos to record the coil whine, with the new video card and a video with the old video card. Also, there is a strange click when turning on and off the PSU, similar to the start of a fan. They are present both with Zero Fan Mode and without it. If needed, I can share the link.
I think I found some connection between this problem and the driver settings. I have a LG 34GK950F monitor. It supports FreeSync 2. If you turn off AMD FreeSync Premium Pro in the AMD driver and set the monitor frequency to 144 Hz – the coil whine disappears. If you reduce the frequency of the monitor to any other value – the coil whine returns. When the AMD FreeSync Premium Pro option is enabled, coil whine is unfortunately always present. There is no coil whine in games or other 3D programs (for example, in UFO Test: Ghosting).
Perhaps these observations will be useful to someone. I think most users with such a combination (NZXT C1200 PDU, AMD 6000-series GPU and 144 Hz monitors with FreeSync 2 support) will have this problem.
I like the FreeSync 2 feature, so I plan to change this PSU to another one from Corsair.
I found Amazon reviews on coil whine regarding TT GF3 on the same platform: https://www.amazon.com/Thermaltake-Toughpower-Crossfire-Connector-PS-TPD-1200FNFAGU-4/dp/B0BF4YRCK8#customerReviews