CoolerMaster SilentPro 1000 Watt (Bronze)
(I know it's too much watt for my system and therefor consuming somewhat too much power because of it.)
It will only consume however much wattage the PC draws. Having a higher wattage PSU doesn't mean that it will draw more wattage from the wall. Though, as you correctly noted it is unnecessary for your current build as your system will only use about 1/4 of that.
It is a 10 year old PSU so it should be replaced when you upgrade the rest of the system anyway.
2 hours ago, Balrog said:
My system is still performing very well for desktop work and Adobe photoshop etc. but it just sucks at gaming.
I would like to play games like The witcher 3, Thomb raider, Red Dead Redemption 2, battlefield 5, GTA 5, TES6 (when it arrives) and last but very important: Skyrim SE (heavily modded and with ENB shader effects).
I like to play at 'Ultra' graphics settings as much as possible. On a 1080p monitor. Minimal FPS: 40. but >60 preferred.
You're going to need to buy a console if you want to play Red Dead Redemption 2...
Honestly the entire system is quite dated and is going to struggle a lot in games, especially the ones you have listed which are quite intensive to run. If it's within the budget you should be looking at a full system replacement. New CPU, motherboard, RAM (need DDR4 for newer systems), new graphics card, and new PSU since your current one will be 10 years old... You can reuse the SSD, HDD, and case.
Here's a quick build list to give you an idea of what sort of budget you could be looking at for such an upgrade.
If you don't want to spend that sort of money on a full system upgrade, then maybe look at a 2nd hand GTX 1060 6GB and grab that. You will still struggle in games due to the older CPU, but you should still see some performance increase from the new graphics card over your current HD5770(?), and when you do eventually upgrade the rest of the system you can carry over the 1060 to the new system.