In short, 32GB will work, yes. See http://rog.asus.com/forum/showthread.php?6851-G74-and-8GB-Memory-DIMMs...&country=&status=

Make sure if you're using windows that you have Professional or Ultimate, since HP is kneecapped to use only 16GB.

It's also worth knowing that maxing out the slots with anything faster than 1333mhz won't take effect, as the fully populated memory slot speed is capped at 1333mhz.

lvfmc wrote:
Ok, Thank you all. So if I buy 4 boards with 8gb each, doesn't matter if they are 1333MHz or 1600, it will run only at 1333, that's right? Even with my CPU (i7 2820QM) which supports 32GB RAM and 1600Mhz? And 32Gb RAM with my G74SX-3DE, i7 2820QM, and Windows 7 x64 Ultimate, will work just fine, right?

Yes to both.....it'll work and it'll run at 1333MHz.

lvfmc wrote:
Thankk you BrodyBoy.
So, the speed is a limitation of the mainbord?
Anyone knows where can I find the specs of the G74SX mainboard?

I don't think its a limitation of the mainboard but rather of ASUS's BIOS. Its likely that the BIOS has some code in it to downclock the RAM if 4 sticks are detected, or it can\t read the SPD settings right on the Plug-n-play sticks when there are four installed. However the fact is I don't think anybody knows whether the limitation is related to what kind of CPU is installed in the G74. The 2630 and 2670QM i7s are by far the most common, and everyone who has ever run aground on the 1333MHz 4-bank RAM limitation has been running one of these. Now of course Intel states that these only support up to 1333MHz, so 1600 would be considered an overclock by asus engineers, who may have thought that 4 sticks overclocked would produce too much heat. But an i7 2820 *may* actually run 4 sticks at 1600, because 1600 is supported by Intel for this CPU and would not be considered an overclock by ASUS engineers. At least that may be what they were thinking.

I guess what I'm saying is that 1600MHz with 4 sticks stands a better chance of working in the G74 with an i7 2820 than it does in any with the 26XXQM variety.

I have my laptop on the way to me with an i7-2760 upgrade, a processor which can indeed run faster RAM than 1333mhz.

I'm wondering why a reputable Asus reseller would recommend the RAM upgrade (4x 4gb 1600mhz) to me if the BIOS downgrades it, so the first thing I'm doing is running CPU-Z to check if I'm getting 1600mhz out of the box (which I doubt very much - someone is having this very problem here)

If not I have a BIOS mod lined up that I'm willing to risk, so watch this space.