Tariq_2 :
burgessanthony :
I doubt it is a particularly good PSU for good components. OEM ones are generally down on their stated wattage. I don't know anything about it, but maybe post the model number so others can help. What is the amperage on the 12V rail(s)?
I think most would suggest trying to save a bit more and upping to maybe £300 where there are options including a new PSU.
it says 15.5amps
If you the +12V only has 15.5A, for the purposes of a modern PC, the PSU is an under-200W one. So integrated GPUs only, basically. A long time ago, it was the 5V rail that mattered, but nowadays, the +3.3V and +5V rails are mostly used by peripherals that don't eat up much power.
OEM power supplies are generally a varied bunch. Some are OK, many are terrible. An HP power supply isn't like getting a branded printer or something - OEM power supplies are generally chosen to power the pre-build PC, no more, and stuff like high-quality capacitors is *usually* out given that prebuilts don't typically have lifetime warranties.
The various 80 plus certifications are a measure of the efficiency, not the overall quality of the PSU. Now, there's a relationship in there, but it's not perfect. It's important to research power supplies as it's the most important part of a PC. Any PSU is guilty until proven innocent - if you see a power supply that's not on a known platform or with professional reviews (absolutely not newegg/amazon customer reviews), stay away.