Question about Corsair CX550 lacking sufficient PCIe power connectors.
Question about Corsair CX550 lacking sufficient PCIe power connectors.
Hello everyone.
My current PSU (Corsair CX550 Bronze, delivering 549.6 watts at 45.8 amps on the 12-volt rail) lacks sufficient power cables. It features two separate cables with 6+2-pin connectors for PCIe and one dedicated 8-pin connector for the CPU, which isn’t enough for my EVGA RTX 3080 FTW ULTRA. This model has three 8-pin connectors.
My alternative PSU—FSP Hydro (K), 600W, supplying 552 watts at 46 amps on the same rail—offers more than adequate cables. It comes with two cables, each containing two 6+2-pin connectors, excluding CPU cables. I’m considering replacing my outdated PSU because it’s five years old. The previous unit has been reliable, delivering power without issues or overheating.
My GPU runs on a Ryzen 5 3600, paired with various storage options: a 512 GB M.2 SSD, a SATA SSD, a 2 TB HDD, and a 4 TB HDD, all spinning at 7200 RPM.
For visuals:
Corsair images: https://imgur.com/dYtovsx
View: https://imgur.com/dYtovsx
FSP specs: https://imgur.com/rjnP75A
View: https://imgur.com/AW9orB7
https://imgur.com/iWQLSV9
View: https://imgur.com/AW9orB7
https://imgur.com/iWQLSV9
my EVGA RTX 3080 FTW ULTRA, equipped with three 8-pin connectors.
Because of intense power demands, none of the PSUs listed are suitable for pairing with your RTX 3080. It’s recommended to consider a PSU rated at 850W (or more, around 1KW) that is well-built.
My new PSU (Corsair CX550 Bronze, provides 549.6 watts, 45.8 amps on the 12-volt rail) doesn’t have sufficient power connectors for my RTX 3080 FTW ULTRA, which requires three 8-pin connectors.
When choosing a PSU, if it doesn’t match the required connectors, you’re either getting the wrong PSU or the wrong components for it.
So far there have been no issues.
If you need to rely on adapters to cover your GPU needs, you might want to check out how many fires are caused by adapters—yes, they can cause serious damage.
I suspect most people think I should opt for a higher-power PSU, but that’s not necessary. You can either switch to the new unit or stick with the old one. Just let me know if you’re safe using the new one.
It seems you have plenty of funds available; in that case, choose either model, but be careful—inspect yourself and your system closely before any damage occurs.
You might want to review this: https://www.youtube.com/watch?v=wnRyyCsuHFQ
Reducing the GPU voltage is one approach, but a power cap would be better. As long as it doesn’t attempt to draw 320W when under load, performance should remain stable.
I would actually be surprised if you told me that system would power up on a 3080 with a CX550. As Lutfij is trying to impart to you, this is a GOOD way to damage hardware and waste a lot of money. Neither of your current power supplies are appropriate or safe.
The question you're asking is similar to, "I purchased a $400,000 Lambo and fitted an old Ford pinto 4-cyl engine. Why does it not perform as expected?" The PSU is essentially the core of the system. You upgraded the chassis and appearance but are puzzled why the low-quality engine isn't functioning properly. That PSU has its place in the world, but it doesn't fit the one you created for yourself. Save yourself the trouble and choose the correct component for the task.
If you own the 3080 FTW3 review here, your graphics card could deliver up to 380W (default setting). With a 5% overclock, it might reach around 400W. Be sure to set a very low power cap. Corsair power supplies generally perform well at delivering their rated capacity, but I personally own two CX550 units in older systems without PCIe GPUs and find their thin, lightweight design quite disappointing. They seem to be made for budget.
When compared, my RM650X has more robust power delivery with additional output leads, and the RM750X/RM850X even outperform it. I wouldn’t be satisfied running an RTX 3080 on a power supply that provides less than 750W.
The definition of "safely" varies. With a substantial GPU power limit, you lower the risk of overloading the CX550, but as @Lutfij mentioned, if your PSU doesn’t have enough output pins for the GPU, you’re using an inappropriate power supply.
How would you manage to connect a third 8-pin PCIe cable? Will your GTX 3080 boot up with just two of those cables connected, or do you need all three power connections? Are you thinking about using one of these adapters?
https://www.amazon.com/Express-Adapter-G...B0796NVNY7
It’s true you’ll only get up to 300W from an 8-pin CX550 connector rated at 150W. What might go wrong if you try to restrict the GPU power? You could overload just the 150W cable with 200W instead of 300W.
You likely won’t see any melted plastic from overheating wires and contacts unless there’s visible smoke. Keep in mind what happens with some 600W 12VHPWR connectors when they overheat—are you ready for a fire? Good luck!
I initially considered using a 2×Molex to 8-pin or a 2×SATA to 8-pin connection, thinking each connector should connect to its own cable. However, I realized it could be risky, so I decided against it. I also checked the PC's power consumption using a wall outlet meter—currently under 530 watts (power spikes are known). Here are the links for reference:
Molex to 8-pin cable: https://imgur.com/rdlAmCQ | View: https://imgur.com/rdlAmCQ
SATA to 8-pin cable: https://imgur.com/X3I2H7Y | View: https://imgur.com/X3I2H7Y
CP-9020121, the one marked grey.
While searching for a PSU, I found a tier list on Reddit and reviewed each PSU's tier letter along with the notes in the spreadsheet from my local market. It indicated that the grey-labeled model was superior and the black-labeled one was inferior.