GA-X79S-UP5-WIFI not working with 64GB RAM at 1866Mhz

[Sanity]

Hi all,

I have a GA-X79S-UP5-WIFI with 64GB RAM, that runs fine at 1600Mhz, but not at 1866Mhz which the RAM apparently runs at. 

The RAM is Patriot Intel Extreme Masters 8x8GB DDR3 PC3-14900C10 1866MHz [PVI332G186C0QK] (http://www.overclockers.co.uk/showproduct.php?prodid=MY-073-PA&groupid=701&catid=8&subcat=817)

I've tried setting the Speed manually, and using the XMP profile, and varying the voltage of both sets from 1.5 to 1.6 but the board still fails to post.  Have to revert back to 1600Mhz each time. Currently running the F4s bios, have tried others though.  Apart from this issue, everything works fine.

CPU : i7-3820
PSU : OCZ ZX Series 850

Any thoughts?

Many thanks.

San.

[Spy]

Same problem with mine, i'm using 4 8GB of corsair dominator 2400mHz

[dmdilks]

Have you just tried 4 sticks to see if you can get it to run at 1866. Yes all boards say that you can run up 32gb or 64gb.

I have read a lot of people having problems when they try to run the max memory on their boards.

If you can get it to run with just 32gb in at the 1866 and than try adding two more sticks and try it.