There is some Elpida mem out there, that even when modded with the 1500 strap, that seems only stable at 26-26.5 mhs or so
I experienced this with a 480 4gb nitro (not nitro+)
They do 30Mh as well.. (those nitro's)
Got 2 Elpida 4G's, one nitro and one non nitro, the nitro one does 30+ and the non nitro one does 29.5 stable.
But this is with custom timings.
Greetings
I can post the ROMs that I am using to get 25 mh if you want to try and edit them and I can test, sadly I'm not too comfortable at editing them myself even though I feel the info posted above is more than enough.
I am about a week away from turning my 3 pc's into 1 unit with risers so am in no rush to re flash the cards for the next few days