problem with new PSU

I ordered a new 600WATT PSU to come with my new x850XT 256MB graphics card both have arrived but when trying to install the PSU I noticed a problem I only have a 20pin motherboard and the PSU has 24pin can I still cennect it and not have a problem or do I need some sort of cennector or just a whole differtant PSU

From what I know you need something like this:
XPCGear

Most new motherboards are becoming 24-pin I think.

In the past all the Mobos I used were 24 pin, my last 2, both the latest ASUS models are 20 pin, with a seperate 4 pin plug elsewhere on the board. And most of the well known PSUs have both types available to my knowledge. What make is this PSU? Just had a look at a couple of el cheapo ones here, not used. Both have the option for 20 or 24 pin. I won't use cheap ones, I just take them out, thats why I've a couple here. Sometimes I give them to someone with a need for a cheap PSU, they can be bought for around £15.00p new. UK. Last time I used one, about 4 years ago, it fried the motherboard with its poor quality connectors.

Not worth risking!

turns out all I had to do was unclip the extra 4 pincs from the PSU but im now having problemes with my x850xt