Question about Corsair TXM 550 gold

[vapour]

Hey Guys,

I originally thought 550 is the max output and not powerful enough to support a I7-7700k and 1080ti build. He claimed 640W is the actual max output of TX550M and will be enough. I couldn't find enough info online to justify, can someone enlighten me? Like the number on the PSU is not really max, how should we determine? Thanks

 

[Rogue Leader]

Yep its not an exact science there really is no way to be able to calculate this perfectly.

Either way based on the total system draws on other sites for a FE 1080ti and we work off the theory here its only a 60w difference between the two cards, so the math works out. Theoretical total system draw of 470w which is likely overstated. Great quality 550w unit, more than enough.

 

[vapour]

Thanks everyone for this thorough and meaningful discussion. I think we learned that a reliable 550W PSU is good enough to support a 7700k and 1080 ti system. When I went through the original post, the op said he bought the TX550M with 1/3 of the price. I don't think even a open box can be that cheap, used is more likely. Since he didn't specify, I think we can only say if the unit is performing as it should be, his rig will be fine. Thank Rogue leader, mousemonkey and 4745454b for pointing this out, although I definitely won't try to get a 1080ti running with my Seasonic M12II 520 Call me coward if you want. Thanks to Jankerson and Vic too.

 

[4745454b]

Everyone has a different load limit. I think I picked my 80% figure from HardOCP's "torture test". They load the PSU up to 75 or 80% of output and hold it there for 8hrs. I've seen on the forum many people pick 50% because there is where max load efficiency. The difference between 50% and 75% is usually around 1 or 1.5% lower. I'm willing to give up greater max efficiency for a lower priced unit and great idle efficiency.

If your eyes glossed over, let me use the previous ~400W load as an example. 400W is 73% of a 550W unit, so I'm fine with running a 400W system on a 550W PSU. If you want to only load a PSU to 50% of it's output, you'll need an 800W unit to power that system. Not a lot of those, you'll probably pick from a 750W or an 850W. My issue with running an 850W is they tend to cost more than a 550W, and at idle they will be horrible. 80+ at gold level and lower doesn't test sub 20% load. And at idle and just surfing the net, modern PCs tend to use around 100W. This is sub 20% load for both the 750 and 850. (It's also barely sub 20% for the 550W.) You might still get 82%, or 80%, but it's possible to get 75% or worse. I'm willing to save the cash at the start, and make sure I stay above 80% while I'm talking on forums.

Finally, don't discount age either. PSUs don't last forever. They do wear out. I love my 450W, but I've had it for nearly 5yrs now I think. I've been looking at what new PSU I will be getting. The hotter you let them get, and the longer they are in use, the sooner you'll need to replace it.

 

[Vic 40]

The newer psu's like the TXM talked about seem to do do good on idle as well when looking at efficiency,well that's from what i've read.

I understand when they say that they recommend a 650watt psu when looking at a new system with a gtx 1080 ti,but when already having a good 550watt psu should the OP be able to run the system on that psu. The 80+ gold psu's are about in reach for most people right now so idle efficiency shouldn't be a problem.Even some 80+ bronze do very well for efficiency on low loads.

 

[vapour]

Well, talked to the OP, he actually has everything new and it was a new I7-7700k and 1080ti build including the TX550M. He lives in Denmark and he returned everything now (Denmark law says 14 days full refund for any online sales, no questions asked, wow) His budget is ~$2900, but Denmark parts are more expensive Already recommended him to build on coffee lake and 1080 ti, and told him 550W+ will do. He decides to get something higher and seasonic. Again, thanks for all the helpful suggestion and comments, really appreciate it.