Looser timings?

[sehcure]

I can get my hyperX grey to run at 1866mhz, but I have to loosen off the timings to 10-10-10-27.

Is this better than running it at 1600 with 9-9-9-27?

 

[thezakarum]

You can probably test this by running super_pi while at 1600mhz settings then trying 1866mhz settings then compare how fast it completes it.

 

[Surveyor]

You have an i5-2500K?

Running at 1866MHz makes very little difference to 1600MHz.

The Best Memory for Sandy Bridge

Sandy Bridge Memory Scaling Choosing The Best DDR3

DDR3 SDRAM for Sandy Bridge: Choosing the Best Memory for LGA1155 Platform

And what sort of voltage are you using for 1866MHz? (see my sig.)