3770k and PC21300/2666mhz DDR3 - normally feasible?

[SirCanealot]

Hi everyone,

I've recently got 16GB of PC21300/2666mhz RAM to use with my 3770k.

However, I've found that I am unable to get it to POST at 2666, the most I can get away with is 2200.

I'm just wondering, do I just have a crappy memory controller in my 3770k? I've more or less maxed all the voltages I can think to play with and have had no luck. Or are they just crappy sticks? All I can see on the internets is some 3770ks will have trouble reaching the 3000+ speeds, but not 2666

I've set the IMC voltage to the 'safe' max of 1.35v and have had no luck. Tried setting VCCIO/VTT voltage to 1.2v (which seems to be the max on my board). And I've tried setting the VDIMM voltage to 1.75v (as these are 1.65v sticks). No luck at all.

If I set it to 2666 it simply does not POST at all and dumps me back into the BIOS and I'm not sure if 2200 is stable even. I've set the timing to what it states on the sticks (11-13-13-35).

My board is an ASRocks Extreme 6 Z77 and the memory is these sticks:
http://www.overclockers.com/forums/showthread.php/728364-Team-Group-Xtreem-8GB-DDR3-2666-C11

Unfortunately going to be away from home for a few days so won't be able to provide any more information. But just wanted to pose the question — does anyone remember is 3770ks had trouble running up to 2666 normally?

If I should be able to get to 2666 fine under normal circumstances, might need to go give my BIOS a good reset and start again

Thanks so much.

 

[Dasa2]

my 3770k had trouble with 2400mhz
if it booted it was stable but it rarely posted
it was happy at 2133c9
tighten timings up as much as you can at 2133\2200 and it will perform much the same if not better than it would a 2666 anyway

 

[BonzaiDuck]

I'd only add this. Find the same model RAM at the lower speed spec, and try the spec timings -- XMP setting if that's possible.

I don't mess with timings anymore, if I can just buy the speed spec I want and run them that way at stock XMP timings.

But -- especially for a 2x kit of RAM and depending on the manufacture -- see if they run at CMD=1. You may have to boost the IMC voltage a tad, but not at all like the OP mentioned above. I've often thought that I could actually "feel" the slight improvement that a tighter command rate offers. Me? I'm S-O-L. It has only worked well with certain RAM kits or pairs thereof for 4 slots filled. Generally, but for the exceptions I note can be found here and there, that's what you live with for four sticks of RAM.

 

[SirCanealot]

Hey everyone,

Thanks so much for the feedback. I'll be back home tomorrow, so I can hopefully do some more testing on this

See if I can get anywhere with 2100/2200 and tight timings at least...

I sort of got the memory to give me something to play with, but currently it's in the annoying state where nothing is working that should be working, so being less than fun now!