What does it mean that the Haswells only support up to DDR3-1600 ram?

Wheel in the Sky

Distinguished
Aug 17, 2013
94
5
18,545
So buying any ram at a higher frequency than 1600MHz will just be used at 1600 if you have a Haswell?

I've seen 1600 stated as the max supported ram frequency a few times: http://en.wikipedia.org/wiki/Haswell_(microarchitecture)#Desktop_processors

http://arstechnica.com/gadgets/2013/06/haswell-is-here-intel-announces-first-4th-generation-core-cpus/2/
"1600MHz DDR3 is Haswell's highest officially supported speed, same as Ivy Bridge."

Or do you need to OC the CPU to get the ram to work at 1866MHz (or higher)? I need to know because that would mean I might get the i7-4770k instead of the locked 4770. Or just buy ddr3-1600 instead of 1866.


...also wondering if anyone knows anything about letting Haswell's integrated graphics (Intel HD 4600) use more of the system ram. Is there a limit to how much you can give it (or a point where it makes no sense)? And can you do this with the 4770 or do you need the 4770k to mess with that?
 
Solution
Just means that any RAM speed above that voids the warrantee, otherwise that RAM does work at the higher Freq. PS SB the Spec was DDR3-1333 and I used DDR3-1600 Even at it's stock speed just fine.

Bottom Line if you want to use the Higer speed Ram, go for it - even at CPU stock speed.
If OCing that voids the warrantee anyway.

On allocating Ram to iGPU (HD4500)
Quote
The card has no dedicated memory of its own; it instead borrows memory from the computer’s main memory (RAM) for graphics use. During normal usage it will draw a negligible amount, and while gaming, the 4500MHD will borrow what it needs to run the game but no more. The 4500MHD will give up memory if the system requires it.
End quote: Ref -...
Just means that any RAM speed above that voids the warrantee, otherwise that RAM does work at the higher Freq. PS SB the Spec was DDR3-1333 and I used DDR3-1600 Even at it's stock speed just fine.

Bottom Line if you want to use the Higer speed Ram, go for it - even at CPU stock speed.
If OCing that voids the warrantee anyway.

On allocating Ram to iGPU (HD4500)
Quote
The card has no dedicated memory of its own; it instead borrows memory from the computer’s main memory (RAM) for graphics use. During normal usage it will draw a negligible amount, and while gaming, the 4500MHD will borrow what it needs to run the game but no more. The 4500MHD will give up memory if the system requires it.
End quote: Ref - http://pcgamingcorner.com/?p=820
 
Solution

Wheel in the Sky

Distinguished
Aug 17, 2013
94
5
18,545
Thanks for clearing that up, Chief. That means I can go with the non "k" version of the 4770, and still use 1866 ram.

As for the iGPU, I was wondering if I can raise the maximum amount of system ram it's allowed to use. It's probably not a big deal, but I may as well look for that option in the bios while I'm setting the ram to 1866.