RAID 0 Slower!!! Pls help

[Busconian]

Last night I bought two 120GB SSDs for $60 CAD. Works great. I put them in RAID 0 (Through Windows) on my Gigabyte b150m board.

 

I ran crystal disk mark and got 900mb+ a second on the read and 650mb+ on the writes. 

 

Now today, I got a new Motherboard, a Asus z270 itx board and put the same two drives in RAID 0 but through the bios to use them as a Windows 10 boot drive.

 

Now when I run crystal diskmark, the C: says only about 500mb a second on reads and writes.

 

Whats the deal??

 

In the intel rapid storage program it says they are in RAID 0. It also says the drive is a 240GB.

[TrigrH]

RST has some settings in it, there are faster options and safer ones.

 

Enabling write back cache will improve performance.

 

[Busconian]

58 minutes ago, TrigrH said:

RST has some settings in it, there are faster options and safer ones.

 

Enabling write back cache will improve performance.

 

Write back cache is grayed out for me?